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Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021
Version: 03
JACK-UP RIG MOVE MANUAL Copy No. 01
Volume 1/1
This manual is the property of SEADRILL and for the use of designated staff only
THIS IS A CONTROLLED DOCUMENT
Revision requests and comments should be forwarded to: Seadrill Corporate Attn.: Operations Excellence
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Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021
Version: 03
TABLE OF CONTENTS 1. INTRODUCTION ........................................................................................................................................................ 4 1.01 1.02 1.03 1.04
PURPOSE........................................................................................................... 4 SCOPE AND APPLICABILITY ...................................................................................... 4 RESPONSIBILITIES................................................................................................ 4 DEFINITIONS OF TERMS.......................................................................................... 4
2. PLANNING AND SEQUENCE OF OPERATION ................................................................................................... 6 2.01
STEP 1 TO 12..................................................................................................... 6
3. GENERAL REQUIREMENTS................................................................................................................................... 8 3.01 CONDUCT OF OPERATION ........................................................................................ 8 3.01.01 Drills and exercises................................................................................................................................ 9 3.01.02 Maintenance and repair work ................................................................................................................ 9 3.01.03 Safety organisation................................................................................................................................. 9 3.01.04 Operational planning meetings............................................................................................................ 10 3.01.05 Damage control.................................................................................................................................... 10 3.01.06 Storm preparedness.............................................................................................................................. 10 3.02 ATTENDING PERSONNEL ....................................................................................... 10 3.02.01 OIM ..................................................................................................................................................... 10 3.02.02 Marine Section Leader......................................................................................................................... 11 3.02.03 Rig Mover............................................................................................................................................. 11 3.02.04 Seadrill appointed Marine Warranty Surveyor (MWS)........................................................................ 12 3.02.05 Client Representative ........................................................................................................................... 12 3.02.06 AHTSV Master ..................................................................................................................................... 13 3.02.07 Positioning Surveyor............................................................................................................................ 13 3.02.08 Manning - Crewmembers ..................................................................................................................... 13 3.03 ATTENDING AHTSV ........................................................................................... 16 3.03.01 Minimum bollard pull requirements..................................................................................................... 17 3.03.02 Criteria for rotating around one pinned Leg (walking the Jack-up).................................................... 17 3.04 SITE SPECIFIC PROCEDURES .................................................................................. 17 3.05 WEATHER ........................................................................................................ 18 3.05.01 Weather window standard requirements.............................................................................................. 18 3.05.03 Measuring sea conditions .................................................................................................................... 19 3.06 GENERAL SOIL AND LOCATION SURVEY REQUIREMENTS ................................................... 20 3.06.01 Potential risks and survey methods...................................................................................................... 20 3.06.02 Location categories.............................................................................................................................. 21 3.06.03 Location coordinates ......................................................................................................................... 21 3.06.04 Water depth at location........................................................................................................................ 22 3.06.05 Survey line spacing .............................................................................................................................. 22 3.06.06 Bathymetric survey............................................................................................................................... 23 3.06.07 Seabed debris survey............................................................................................................................ 23 3.06.08 Shallow seismic survey......................................................................................................................... 23 3.06.09 Geotechnical investigations ................................................................................................................. 23 3.06.10 Sampling and testing ............................................................................................................................ 24 3.06.11 Site investigation requirements ............................................................................................................ 24 3.06.12 Geophysical site survey requirements.................................................................................................. 24 3.06.13 Requirements to individual subcontractors.......................................................................................... 25 3.07 LOAD AND STABILITY CALCULATIONS ........................................................................ 26 3.08 PASSAGE PLAN AND NAVIGATIONAL PROCEDURES .......................................................... 26
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Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021
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3.09 SECURING FOR THE TOW ...................................................................................... 27 3.10 TOWING GEAR .................................................................................................. 28 3.10.01 Emergency towing gear........................................................................................................................ 30 3.11 CONTINGENCY PLANS AND PROCEDURE ...................................................................... 30 3.12 COMMUNICATION ............................................................................................... 31 4.
OPERATION ....................................................................................................................................................... 31 4.01 MOVING OFF LOCATION ........................................................................................ 31 4.01.01 General procedures.............................................................................................................................. 31 4.01.02 Jacking operation................................................................................................................................. 32 04.01.03 Jetting................................................................................................................................................... 33 4.01.03 Use of towing vessels ........................................................................................................................... 33 4.01.04 Use of anchors ..................................................................................................................................... 34 4.02 TRANSIT ......................................................................................................... 34 4.02.01 General procedure ............................................................................................................................... 34 4.02.02 Watch keeping ...................................................................................................................................... 35 4.02.03 Weather observations........................................................................................................................... 36 4.02.04 Position reporting ................................................................................................................................ 37 4.02.05 Crane operations.................................................................................................................................. 38 4.02.06 Minimum bunkers of diesel and portable water for passage................................................................ 38 4.03 GOING ON LOCATION .......................................................................................... 38 4.03.01 General procedures.............................................................................................................................. 39 4.03.02 Conditions on location ......................................................................................................................... 39 4.03.03 Approach.............................................................................................................................................. 40 4.03.04 Anchor operations................................................................................................................................ 41 4.04 PRELOADING .................................................................................................... 42 4.05 SPECIAL SOIL CONDITIONS .................................................................................... 44 4.06 JACKING TO FINAL AIR GAP .................................................................................... 44 4.07 CLAMPING AND SKIDDING OF DERRICK ...................................................................... 45
5.
REPORTING AND FORMS............................................................................................................................... 45 5.01 5.02
CHECKLISTS ..................................................................................................... 45 TEMPLATES ...................................................................................................... 45
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Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021
Version: 03
1. INTRODUCTION 1.01
Purpose The purpose of this manual is to outline and provide minimum requirements to ensure that planning, towage, positioning and preloading of Seadrill Jack-ups are carried out in a safe and efficient manner.
1.02
Scope and applicability This manual contains requirements and information that is needed to perform the activities as per above and sets minimum standards to ensure that each operation is performed in such a way that it complies with Seadrill’s policies and directives. This rig move manual is issued by Seadrill Corporate and shall be considered as a set of minimum requirements. In addition to these requirements, all international and local country rules and regulations shall be implemented and included in the site specific rig move and preload procedures issued for each rig move operation.
1.03
Responsibilities This manual and its subsequent revisions shall be approved by the COO. The local Marine Superintendent (or Marine Responsible) is responsible for ensuring that these requirements are incorporated into the site specific procedures. Seadrill Corporate is responsible for the continuous review and update of this manual based on lessons learned and feedback from the rigs and regional offices.
1.04
Definitions of terms Definitions in this manual are in accordance with ISO 8402 standard. Those definitions which are not included in that standard are in accordance with the terms of ISO 9004 or the Company's own definitions. AHTSV Bathymetric Survey BP Certificate of Location Approval (COLA)
Cone Penetration Test (CPT) Extended field move Field move
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Anchor Handling Towing supply Vessel To determine the water depth and any slope of the seabed at the desired location site and to ensure a safe navigable approach to the site. Bollard Pull. The document which verifies that a specific offshore unit can be safely installed on a specific location and be safely operated within the limitations of the Jack-up Marine Operation Manual (MOM) applicable to the unit and the planned operations. The COLA will be issued by a recognised Marine Warranty Surveyor. To obtain soil resistance data to enable the prediction of leg penetration. A move where the duration of towage exceeds 12 hours and standby location(s) are required. A move where the duration of towage is below 12 hours.
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Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021 Grab Samples Jack-up Emplacement of a Jack-up
Magnometer Survey Marine Section Leader Marine Warranty Surveyor (MWS)
Ocean tow Rig Mover ROV Shall, Should & Can
Shallow Seismic Survey Side Scan Sonar Survey SNAME
Soil Bore (Coring) Swiss Cheese drilling Tow Bridle
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Version: 03 To confirm the composition of the seabed sediments and provide Coring Survey information on scour potential. A mobile platform that stands on the seabed on supporting legs. The act of bringing an offshore unit onto a new location and includes placement of the structure/anchors and the load tests required to verify the capability of the soil to withstand the maximum forces induced. A survey carried out in order to identify and map sub-seabed metallic objects. Barge Master or Stability Section leader A company approved by Seadrill’s underwriters which have been nominated by the COO to issue the COA for installation of a Seadrill Jack-up and the issuance of verification documents (Towage Certificate, Tie-Down Certificate etc) on the accomplishment of intermediate stages of the operation. A move where the duration exceeds 12 hours and no stand-by locations are available. Tow Master Remote Operated Vehicle Any text which does not describe how work Shall be carried out shall be confined to guidelines. The following definitions apply to all documents Shall: A requirement which is mandatory. Should: Refers to a recommendation. Alternative solutions of the same functionality or quality may be applied. Can: Refers to one of several solutions of equal functionality or quality. A subsea survey carried out to identify and map possible shallow gas accumulations and to obtain information about the configuration of the sub-seabed soil within the foundation zone. A subsea survey carried out to detect any objects or obstructions and to map the seabed in order to investigate it's topography and variations in sediment cover. The Society of Naval Architects & Marine Engineers (Publisher of the standard: Site Specific Assessment of Mobile Offshore Drilling Units 5-5A) To provide sufficient data to calibrate and ensure proper geotechnical and geophysical analysis. Perforation drilling, which is drilling a specified number of holes below the intended spud can location to weaken the formation. Main towing arrangement used in connection with the lead tug of the tow.
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Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021
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2. PLANNING AND SEQUENCE OF OPERATION In order to maintain regularity during the planning and issuance of the operation site specific rig move procedures as well as the preload procedures, it is recommended to follow the planning and sequence of operation as outlined below.
2.01
Step 1 to 12 The planning and sequence of operations have been divided into the following 12 steps: Preparation
1. 2. 3. 4. 5. 6. 7.
Execution
8. 9. 10. 11. 12. 13.
Client location request? Requesting soil and seabed information from client Geotechnical investigation Preparing site specific procedures Requesting Location Certificate of Approval (COA) Marine Warranty Surveyor’s requirements (MWS) Onboard review of the site specific procedures Preload simulation Onshore pre-move meeting Preparing for rig move Rig move Preloading and final accepting Post Rig Move report
Step 1 – Client location request? This step will be the result of successful negotiations leading to a drilling contract, and does normally not include anything else than collecting various operational information which may be required by the Seadrill Regional Office. Step 2 – Requesting soil and seabed information from client This step will under normal circumstances be handled by Seadrill Regional Office. It is essential that this data is requested in such a time that all geotechnical examinations and calculations can be carried out in a professional and satisfactory manner. Especially in areas with special soil conditions which could lead to rapid penetration and/or punch-through. (See section 3.06). Step 3 – Geotechnical investigation In order to have the full understanding of the sub-seabed soil all available data shall be forwarded to the Seadrill Marine Engineering Group or geotechnical subcontractor for analysis. That will result in a foundation assessment being issued, giving estimated penetrations and ascertain any risk of rapid penetration and/or punch-through. The sub-contractor shall be approved as per section 3.06.13
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Rig Move Manual
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Step 4 – Preparing site specific procedures The Seadrill Regional Office will at this stage start preparing the site specific rig move and preload procedure. For the rig move procedure see section 3.04. For the preload procedure see sections 4.04 and 4.05 Step 5 – Requesting Certificate of Location Approval (COLA) Upon receipt of the results of the geotechnical examinations and calculations, the Seadrill Regional Office has to forward all documentation to an approved MWS for review and issuance of a COLA for the site specific location and covering the emplacement of the specific Jack-up in question. For approved Marine Warranty subcontractor see section 3.06.13 Step 6 – Marine Warranty Surveyor’s requirements (MWS) Upon receipt of the COLA the Seadrill Regional Office will implement any recommendations and requirements into the site specific rig move procedure and preload procedure and these shall be fulfilled, this is to satisfy the requirements of our underwriters For the rig move procedure see section 3.04. For the preload procedure see sections 4.04 and 4.05. Step 7 – Onboard review of the site specific procedures When the draft procedures have been completed by the Seadrill Regional Office, they have to be forwarded to the Rig Manager, OIM, Marine Section Leader, Rig Mover and, if deemed necessary, the MWS, for review and comments. If relevant, the comments shall be implemented into the procedures by the local Marine Superintendent or Marine Responsible person. The procedures will have to be finally approved as per section 3.06.02. Step 8 – Preload simulation When the preload procedure has been agreed between the Seadrill Regional Office and the Jack-up, the Jack-up has to prepare a preload simulation based on the procedure and actual/ estimated deck load. The preload simulation shall be approved by the Seadrill Regional Office. See section 3.06.02, 4.04 and 4.05. Step 9 – Onshore pre-move meeting When all procedures are completed within the Seadrill Regional Office all involved parties have to attend an onshore/offshore pre-move meeting by means of a teleconference call at which each procedure shall be reviewed and agreed upon. Minutes of this meeting form part of the post rig move report.
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Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021
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When agreement has been reached, any comments or corrections shall be implemented into the procedures and forwarded to the designated responsible persons for acceptance and signature. If any comments or corrections arise after the final acceptance, a non-conformance shall be forwarded and approved by all involved parties. See location categories and approval level in section 3.06.02. For non-conformities, please refer to TMS, Directive DIR-00-0011 – “Handling of non-conformities”. Step 10 – Preparing for rig move At this stage the Jack-up should prepare for rig move according to the Marine Operations Manual and to the satisfaction of the MWS. In this respect the MWS shall issue a Seaworthiness / Tow Approval Certificate stating that the Jack-up is ready for the planned rig move and that all criteria in the rig move procedure are fulfilled prior to commencement of the rig move. Step 11 – Rig move The rig will now commence the actual rig move by jacking down at present location, pull off, transit, emplacement at the new location, preload and jack up to final air gap. Please see sections 4.1, 4.2 and 4.3. Step 12 – Preloading and final accepting When the final position has been accepted by the operator’s representative the Jack-up will be preloaded according to the preload procedure and to the acceptance of the attending MWS. Upon completion of preloading and acceptance by the attending MWS, the Jack-up will be jacked up to the operational air gap as required by the operator however always higher than the minimum required operational air gap as stipulated in the location approval. The final air gap has to be accepted by the operator’s representative before commencement of drilling operations. Please see section 4.06 and 4.07.
3. GENERAL REQUIREMENTS 3.01
Conduct of operation While Jack-ups are departing a location, in transit or during emplacement at a new location they operate outside their normal mode wherefore the OIM shall be aware of the requirements set in the specific rig move procedure. Furthermore, it is of paramount importance that the attending AHTSV and other involved services have been verified to have the capability and capacity to perform the functions required to accomplish the operation. The MWS plays a vital and central role in this verification process.
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Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021
Version: 03
With exception of the check lists in section 5 of this manual, the directions in this Rig Move Manual are minimum requirements and guidelines based on good offshore marine practices and marine standards supplemented by the experience gained by Seadrill’s organization during the years. This Rig Move Manual shall not substitute any mandatory rules and regulations issued by a Continental Shelf Authority, Flag State or any other authority having legal rights on the Jack-up concerned. 3.01.01
Drills and exercises
Drills and exercises shall be carried out as specified in TMS. Additional special drills may be required if the rig move operation involves a number of non-regular crew members. Where alterations to the Station Bill are required for the intended voyage or upcoming operation, they shall be prepared in due time and the crew shall be instructed accordingly. Drills shall be carried out to ensure that all crew members have understood the changes and are able to act promptly. Exercises and drills should always be recorded in the appropriate log book. 3.01.02
Maintenance and repair work
Maintenance and repair work during the rig move shall be planned with the responsible parties, i.e. Rig Manager, OIM, Marine Section Leader, Technical Section Leader and the Rig Mover. Care shall be exercised to ensure that all systems and equipment vital to sea-worthiness remains unaffected throughout all phases of the operation. • Heavy equipment shall only be used or dismantled when conditions are such that safe handling can take place within the pitch/ roll and heave imposed on the Jack-up. • Large modification work should be conducted only by a dedicated Project Manager, who works in close contact with the OIM, Marine Section Leader, Technical Section Leader and Rig Mover. • The Permit to Work System shall be strictly followed and all permits to be signed by the OIM. • If work has been commenced and cannot be completed prior to adverse conditions, the work shall be suspended and the area shall be secured with adequate barriers and signage. 3.01.03
Safety organisation
During rig moves the number of personnel on board will be reduced and the OIM shall ensure that the valid Station Bill, and the positions stated herein, can be manned with the personnel available on board. If this is not the case, the OIM and the rig management must, prior to commencement, create an alternative safety organisation and Station Bill addressing the situation. The personnel onboard has to be instructed and trained accordingly.
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Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021 3.01.04
Version: 03
Operational planning meetings
The operation plan is acknowledged by the Client in the formal pre-move meeting conducted onshore. Prior to commencing each step of the operation, it is important that the OIM conducts meetings with management of the rig move as well as TBRA (Task based risk assessment) and Toolbox Talks with the participating crew. 3.01.05
Damage control
The OIM shall have damage control equipment readily available on board the Jackup to facilitate temporary repairs. 3.01.06
Storm preparedness
During the transit of a Jack-up, the weather can change rapidly wherefore close monitoring is essential. Despite weather reporting services being arranged, the unit shall be prepared at all times for adverse weather conditions. If the weather situation deteriorates in such a way that safe jacking on an alternative location cannot take place, the OIM must, in consultation with the MWS and Rig Mover, evaluate the possibility of lowering the legs to a predetermined position to improve the stability and reduce the stress imposed on the legs. This decision should be carefully evaluated and executed well in advance before reaching the limitations stipulated in the Jack-ups Marine Operations Manual especially for units with leg fixation systems as these can take several hours to disengage. The maximum towing speed when lowering the legs shall be adhered to. Whenever the weather deteriorates, additional monitoring shall be undertaken to confirm the watertight integrity and to verify all lashings and tie downs are still in place and secure.
3.02
Attending personnel All work related communication shall be in English.
3.02.01
OIM
The OIM has a total responsibility for the safety of the rig and personnel at all times as per statutory requirements and he/she is responsible for ensuring that all operations are conducted in such a manner as to safeguard the integrity of all Seadrill assets and third party equipment. The OIM decides when it is safe and practical to commence operations within the limitations of the Marine Operations Manual, having consulted with the Marine Section Leader, Rig mover, MWS and Client Representative. The OIM approves commencement of jacking operations. The OIM reports the progress of the operation to the onshore management every 6 hours as a minimum.
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Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021 3.02.02
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Marine Section Leader
The Marine Section Leader is responsible for ensuring that all aspects of the rig move are performed safely and efficiently. He/she liaises with the OIM, MWS, Rig Mover and Client Representative on all matters concerned with the move. He/ she is responsible for operating the jacking control panel. He/she ensures that the stability complies with the Marine Operations Manual at all times, including making any adjustments to trim or heel as necessary in consultation with the MWS. He/she ensures that the watertight integrity of the unit is not impaired and that all watertight closing devices are functioning properly, reference is made to 4.02.02. Note: - It is essential that watertight openings are kept closed, whilst the unit is afloat, or during jacking operations. If it is necessary to open a watertight opening to allow passage between one compartment and another - this may be done, but the opening shall be closed immediately after passing through. He/she ensures that the towing and emergency towing gear are in place, in good condition, complete with certification and ready for immediate deployment. He/she ensures that competent Seadrill personnel are available for the safe deployment of the rig’s towing gear to the AHTSV. He/she ensures that all jacking and jetting systems are function tested prior to commencement of the operation and that all pumping systems are fully operational. All bilges and strum boxes are to be checked and cleaned if required. He/she ensures that the sea fastenings of all equipment and cargo are adequate and completed to the satisfaction of the Marine Warranty Surveyor. The Marine Section Leader is responsible for verifying that all checklists pertaining to the move have been completed and signed off prior to commencement of the move. 3.02.03
Rig Mover
The Rig Mover liaises with the Seadrill OIM, MWS, Technical Section Leader and Client Representative on all matters concerned with the operation. He/she confirms that the rig's towing equipment is suitably certified and in good condition and that all communication systems are functioning correctly. He/she is responsible for the conduct and safety of the rig during the tow and will give instructions to the towing vessels with respect to tow wire deployment, passage planning, courses and speeds, after consultation with the Seadrill OIM, MWS and AHTSV Masters.
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Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021
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He/she liaises with the AHTSV Masters on all manoeuvres from hooking up boats, under tow, disconnecting, moving to stand off position, running of anchors prior to moving to the final positioning including direct communication with the jacking control room. He/she requests commencement of jacking operations and preloading operations in consultation with the OIM, Marine Section Leader, Marine Warranty Surveyor and Client Representative. 3.02.04
Seadrill appointed Marine Warranty Surveyor (MWS)
The MWS liaises with the Rig Mover, Marine Section Leader and OIM on all aspects of the move to ensure the operation is carried out in compliance with the Marine Operations Manual and site specific procedures. The MWS issues a Towage Approval Certificate when he is satisfied that the Jack-up and attending AHTSV(s) are in a seaworthy condition and can commence the tow in a safe manner. Th e MWS will veri fy t hat t h e t owing eq uip m en t is i n g ood con dition an d t hat all communication systems are functioning correctly. The MWS, in conjunction with the OIM, Marine Section Leader and Rig Mover, decides when it is safe and practicable to commence operations within the limitations of the unit's Marine Operations Manual and the long range weather forecast(s). The MWS monitors jacking, rig move and pre-loading operations. The MWS liaises when necessary with the Client Representative as required on all matters concerned with the rig move operation. The MWS verifies that the rig has acceptable stability at all times and he shall advise on making adjustments to trim or heel as necessary. The MWS verifies, in consultation with the Marine Section Leader and the Rig Mover, that the rig has sufficient positive stability and water depths throughout all stages of the operation. 3.02.05
Client Representative
The Client Representative is responsible for protecting the Oil Company’s assets. He/she verifies compliance with the site specific and approved rig move and preload procedures. He/she verifies that the operation is carried out in accordance to the client’s procedures where required when approaching a platform or subsea structure/pipeline.
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He/she liaises with the survey positioning contractor, Rig Mover and Marine Section Leader with respect to the navigational equipment status and position confidence at the final approach to a location. He will also keep the onshore drilling manager updated with ongoing and future planned operations. The Client Representative is responsible for the acceptance of the final position of the Jack-up. 3.02.06
AHTSV Master
The AHTSV Master is responsible for the safety of own vessel. He/she is responsible for ensuring that all towing operations are conducted in a safe manner with due regards to safe navigation, safe working practices and good seamanship. He/she has the obligation to request for a consultation with the Rig Mover, OIM, Marine Section Leader, MWS, and Client Representative to turn the tow and head for shelter in the event of an increasing weather forecast or encounters unexpected bad weather. The OIM is overall responsible and may instruct the Rig Mover to inform the vessels to head for shelter should he deem the situation warrants it. He/she ensures that AHTSV crew is familiar with the towing operation. By the use of a risk assessment process, he/she shall ensure that all hazards have been identified and communicated to the crew prior to each towing operation. He/she reports on any known damage to equipment or vessel to the OIM, Marine Section Leader and Rig Mover at the time of being aware of the damage or at the earliest opportunity thereafter. This information will be communicated to all other relevant parties by the OIM. He/she ensures that appropriate navigation warnings, similar to below, are transmitted on the hour or on approach of other vessels on the Safety Distress VHF Channel 16 or appropriate navigational channel for specific area. 3.02.07
Positioning Surveyor
The Positioning Surveyor is responsible for the proper operation of the positioning equipment and providing constant data showing the position of the unit at all times during the tow and at the proposed location including the stand-off position. He/she performs system checks to prove navigation system confidence prior to departure from the present location and at intervals during the tow and during location positioning operations. He/she will immediately report failures and/or shortfalls in navigation equipment to the OIM, Marine Section Leader, Rig Mover and Client Representative. 3.02.08
Manning - Crewmembers
The minimum manning shall comply with the requirements stipulated by the Country of Registration (Flag State) and the Continental Shelf Authority. The
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requirements of the Flag State are stipulated in the Safe Manning Certificate which is part of the Jack-up certification record. The number of crew members carried on board the Jack-up during the move shall be limited to essential personnel only with due consideration to the evacuation means available (helicopters, boats etc.). The maximum number of People on Board (POB) shall not exceed the capacity of one lifeboat or 60 persons onboard, which ever is the lower number. This applies to “Extended” field moves and Ocean tows. For infield moves this POB limit can be adjusted based on compliance of the table below. ADDITIONAL MITIGATIONS THAT CAN BE IMPLEMENTED, AS PART OF "DISPENSATION FROM NORMAL OPERATING PROCEDURES", TO EXCEED 60 POB (UP TO ULTIMATE MAXIMUM OF 90 POB) TWO HELICOPTERS SUPPORT AVAILABLE in < VESSEL (or 60mins away, or ONE SPARE AHTS) HELICOPTER AT ALL TIMES (60mins away) & (plus OTHER FACILITIES operational
ACTIVITY & SERIOUS HIGH-POTENTIAL POB OF UP HELICOPTER AVAILABLE ALWAYS WITHIN 15 RISKS PRESENT DURING ACTIVITY TO 60 in < 60mins MILES radius
Cranes & Billy Pugh on Rig)
1. Jacking Down a. Wind above operational limits
YES
b. Sea-state above operational limits
YES
c. Structural failure of legs
YES
d. Failure of jacking gear
YES
e. In-field vessel collision
YES
f. Errant passing vessel collision
YES
g. Live pipeline(s) in vicinity of platform
YES
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60 POB + capacity of chopper 60 POB + capacity of chopper 60 POB + capacity of chopper 60 POB + capacity of chopper 60 POB + capacity of chopper 60 POB + capacity of chopper
Approved by: Per Wullf
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
No POB above 60 allowed
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Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021
Version: 03
2. Wet Tow/Positioning a. Wind above operational limits
YES
b. Sea-state above operational limits
YES
c. Loss of tow (hawser/tug failure)
YES
d. Loss of stability (shifting loads)
YES
e. Loss of water-tight integrity
YES
f. Shallow water depth (unknown)
YES
g. Extreme water depth (unknown)
YES
h. In-field vessel collision
YES
i. Errant passing vessel collision
YES
60 POB + capacity of chopper 60 POB + capacity of chopper 60 POB + capacity of chopper 60 POB + capacity of chopper 60 POB + capacity of chopper 60 POB + capacity of chopper 60 POB + capacity of chopper 60 POB + capacity of chopper 60 POB + capacity of chopper
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
up to 90 POB
3. Jacking Up a. Wind above operational limits
YES
b. Sea-state above operational limits
YES
c. Structural failure of legs/jacking gear
YES
d. Failure of jacking gear
YES
e. Punch through
YES
f. Rapid penetration
YES
g. Collision with platform
YES
h. In-field vessel collision
YES
i. Errant passing vessel collision
YES
j. Live pipeline(s) in vicinity of platform
YES
60 POB + capacity of chopper 60 POB + capacity of chopper 60 POB + capacity of chopper 60 POB + capacity of chopper 60 POB + capacity of chopper 60 POB + capacity of chopper 60 POB + capacity of chopper 60 POB + capacity of chopper 60 POB + capacity of chopper
No POB above 60 allowed
A TBRA Shall be completed and signed by the participating persons including the client rep for carrying more persons than 60 POB. That is to ensure definite conformation of helicopters, boats, etc. will be available. The signed TBRA shall be included in the appendix to the rig move procedure. The minimum core crew recommended on board a Jack-up during a field move or ocean tow should consist of following: • 1 OIM • 2 (two) Marine Section Leaders depending on duration of preloading operations. • 1 Maintenance supervisor • 2 (two) Electricians
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Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021 • • • • • • • •
2 2 2 1 2 2 1 3
Version: 03
(two) Mechanics (two) Motorman two) Radio Operators (one) Cook (two) Stewards (two) Crane Operators (one) Welder (optional) (three) Seaman skilled persons
It is not always required to have a Marine Warranty Surveyor attending during the entire move, however, in order to issue a COLA the Marine Warranty Surveyor shall attend the Jack-up prior to commencement of the move for surveying the unit and issuing the COLA.
3.03
Attending AHTSV All AHTSV shall be fit for the purpose for the intended operation. All involved vessels shall be in compliance with standards stipulated in the COLA, the Jack-up Marine Operations Manual and recommendations issued by the attending MWS. All trading certificates shall be valid and all vessels shall be able to communicate in English around the clock. The AHTSV and its equipment shall be inspected and approved prior to commencement of the towing or any anchor handling operation. In situations when this inspection is not practicable, the record from a previous inspection should be consulted and/or a valid certificate from a recognized MWS shall be presented e.g. Marine Warranty Towing Vessel Approval Certificate. The inspection shall as a minimum include the following items: • Bollard pull/ BHP meet the minimum requirements for the particular unit • Towing and work winches – primary and secondary • Auxiliary winches • Stern rollers and mechanic stoppers (E.g. Shark Jaws / Karm Forks) • Main and spare towing wires • Work wires, shackles, connecting links and any other equipment planned to be utilized during intended work scopes • Crew list including position on board and qualification notes • All vessels shall be suitable manned in accordance to legislation and work scope and shall be capable of operating on a 24 hours continuously basis, if required within the work scope The following certificates shall be available and presented upon request. All certificates shall be valid without any notation of restrictions which could affect required performances and have an impact on intended operations: • Certificate of Registration • Class Certificates for Hull and Machinery • Safety Construction Certificate • Safety Equipment Certificate
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Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021 • • • • • • • • •
Version: 03
Radio Safety Certificate MARPOL Certificates ISPS Certificate Tow Wire Certificate including spare wire Bollard Pull Certificate Various Certificates for Towing and Anchor Handling Equipment Latest survey report shall be available for review Outstanding conditions of Class BHP of engines
Verification shall be obtained to ensure that sufficient fuel, lube oil and potable water are available for the expected duration of operation including 25% spare. General suitability check shall be performed to confirm that communication and navigation equipment are suitable, sufficient and operational. In shall be confirmed that there are no operational limitations placed on the vessel. 3.03.01
Minimum bollard pull requirements
The minimum required bollard pull, as specified for the individual Jack-up, shall be stated in the rig move procedure. Refer to TMS doc for more details on bollard pull requirements 3.03.02
Criteria for rotating around one pinned Leg (walking the Jack-up)
Positioning any Jack-up by rotating around a pinned leg is not normally allowed and can only be approved by the COO. Such approval • • • • •
3.04
will require information and calculations as follows: Maximum pull applied from the AHTSV Maximum penetration of the leg which the Jack-up is rotating around Maximum seabed torsion resistance Maximum torsion arm Angle of rotation (degrees of turn) shall be minimized and stated in the approval.
Site specific procedures For every Jack-up rig move a site specific rig move procedure and a site specific preload procedure have to be developed. Both shall be in English. The purpose of these procedures is to assist and guide the OIM, Rig Mover and other personnel involved in the move. The contents of the site specific procedure shall address: • Introduction and purpose of the operation • Personnel responsibilities • Environmental conditions • Navigation package and communication • Departure from present location • Tow and assist vessels
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Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021 • • • •
Version: 03
Tow route and waypoints Positioning (open locations) Preloading Piracy/Rig security
The content of the site specific pre-load procedure shall address: • Summary of precautionary standard operations • Summary of precautions for punch through potential • Settlement and rapid penetration • Action in the event of slow settlement • Action in the event of rapid settlement or punch through • Contact details • Soil foundation assessment • Pre-loading sequence • Precautions during pre-load operations Where plans are forwarded by the client, the details shall be reviewed by the regional Marine Responsible and incorporated into Seadrill procedures. The final site specific procedures will be forwarded to all involved parties for their approval and signature and constitute the basic guidelines for the rig move to be executed.
3.05
Weather The establishment of good quality weather forecasting, which should be both site and route specific, is essential for identifying the weather window required and for the safe conduct of the operation. The established arrangement should as a minimum provide forecasting twice a day and the arrangement has to include immediate update if there is a significant change (e.g. gale warning) in the predictions. It is advisable to commence the forecasting timely thus having a possibility of evaluating the development of weather pattern etc. and making the necessary comparison between the forecasted and actual weather. Besides the established forecasting all other available meteorological data and information related to the area of operation and route should be studied closely. Units that do not have a weather facsimile installed should consider taking a portable instrument in use, especially where ocean tow is being planned. The decision to commence a rig move shall be based on a suitable window.
3.05.01
Weather window standard requirements
During Field Moves two independent weather centres shall have identified and documented a weather window suitable for: • The safe lowering of the unit on location of departure • The safe transit from location to location • The safe installation of the unit and preloading • The safe elevation of the unit on location of arrival
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Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021 During Extended and documented • •
Version: 03
Field Moves two independent weather centres shall have identified a weather window suitable for: The safe lowering of the unit at the location of departure The safe transit from the location of departure to a nominated and accepted location of refuge on the route where the tow can be in a sheltered area or the unit can safely jack out of the water and take the required preload on board.
During Ocean Tow two independent weather centres shall have identified and documented a weather window suitable for: • The safe lowering of the unit at the location of departure and a minimum of three days route forecast where acceptable weather conditions prevail. • There should be no indication that a tropical cyclone is under development which could have a severe impact on the tow. 3.05.03
Measuring sea conditions
Weather forecasts should always be compared with the actual weather observations made onboard the Jack-up. If instrumentation for recording weather and sea condition is available, data should be captured frequently and logged. Self-elevating units, which are not equipped with instrumentation for wave recording, can besides the general observation and recording use the following method for establishing sea-conditions as wave height, period and length: • Observe from a suitable position in the leg well, the ladder steps or rack teeth at the waterline. • Observe and note for 10 minutes at hourly intervals the number and height of waves passing and record the number of waves and their respective heights. • List the number of waves 2', 3', 4', 5', 6', etc. When a 10 minute period of observation has been noted calculate as follows: •
Multiply the wave height by the number of waves to obtain multiplier.
•
Add all the multipliers together.
•
Divide by the number of waves, which will give the average wave height.
•
Divide the number of waves by 600; this being the number of seconds in 10 minutes. This will give you the average wave period per second.
The average wave height and period should then be plotted on an hourly graph. After several hours a trend will become apparent and this could predict a potential jacking period well in advance.
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Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021 3.06
Version: 03
General soil and location survey requirements The objective of this section is to provide specific “Terms of Reference” for the MWS appointed to issue the COLA and for those involved with the planning of the emplacement of the Jack-up. Actual requirements will vary based on the type of Jack-up, the nature of the operation and the features of the area and seabed concerned. Information shall be made available in sufficient time to allow for the COLA authorization process, and for Seadrill to prepare site specific procedures, issue instructions and authorization to the attending Rig Mover. Note: All stand-off and emergency locations shall be surveyed in accordance with this procedure.
3.06.01
Potential risks and survey methods
Risk
Evaluation and Prevention Methods
Installation obstacles
Bathymetric / Seabed surveys.
Punch-Through
Shallow seismic survey. Geotechnical site investigation and soil testing. Bearing capacity analysis to determine risks of punch through. Recommend the various methods of preloading to minimise punch through.
Bearing failure & settlement under storm loading conditions
Shallow seismic survey. Geotechnical site investigation and soil testing. Bearing capacity analysis to determine risks of bearing failure or settlement. Preload to full capacity Shallow Seismic survey. Geotechnical site investigation and soil testing. Bathymetric survey. Determine seabed current strength. Carry out regular inspections and maintain records of the spud can to check for scour. Consider installing sand /gravel bags to protect against scour. Increase spud can penetration.
Site specific assessment to be carried out Sliding failure
Scour
Legs stuck in the formation
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Geotechnical site investigation and soil testing to determine risk. Use and testing of jetting system, educator pipe etc.
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Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021
Version: 03
Foot prints of previous jack ups
Review location records. Consider filling old foot prints. Consider re-orientation of the jack up to avoid foot print holes.
Submerged metal objects / wrecks pipelines and cables Shallow gas / Gas pockets
Magnetometer survey. Seabed Survey by ROV / Diver.
Sub-surface faults
Geophysical survey.
Geological hazards
Soil sampling and geotechnical analysis Seabed surface survey.
Seabed faults (depressions), reefs, rock pinnacles, wrecks etc.
Side scan sonar. ROV inspection. Diver’s visual inspection.
3.06.02
Geophysical survey.
Location categories
The various locations have been divided into four categories as follows:
Note:
•
Category A A COLA has previously been issued for this particular Jack-up at this location.
•
Category B A COLA has previously been issued for similar type of Jack-up and all soil and location survey data is available for this location.
•
Category C Any type of Jack-up has previously been emplaced on this location.
•
Category D No JACK-UP has previously been emplaced at this location.
Of above four location categories Type A & B can be approved by the Seadrill Regional Office. Categories C & D can be approved by the Regional Office unless these locations have a risk of rapid penetration or punch through, in which case Seadrill Corporate shall approve the site specific pre-load procedure. Corporate approval could involve third party review of all procedures as well as attendance by an observer (Marine Surveyor) appointed by Corporate.
3.06.03
Location coordinates
The location coordinates are expressed by latitude and longitude in degrees, minutes and seconds and should be at least 2 but preferably 3 decimal places for accuracy and shall include the datum used. I.e. international spheroid, WGS 84 ED50 etc. and the projection used UTM zone.
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Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021 3.06.04
Version: 03
Water depth at location
This should be provided in relation to chart datum, meaning sea level or lowest astronomical tide stating which reference has been used. 3.06.05
Survey line spacing
In general, the surveyed area shall as a minimum be 1 x 1 km square centered on the designated location. Two line grids each consisting of a minimum of 11 lines, spaced at 100 meters intervals shall be acquired in orthogonal directions to cover the survey area. The centre lines of the line grids shall intersect at right angles at the designated location. The program of lines shall total be (11+11) x 1= 22 kilometers, excluding any necessary extensions to accommodate towed equipment or to enhance data interpretations. Line separations shall be reduced to a maximum of 50 meters within 200 meters of the designated location, where indicated, by the complexity of seabed relief and sub seabed soil conditions. The grid may be modified in accordance with the characteristics of the equipment used. However deviations from the overall orthogonal grid pattern should be avoided. The survey grid orientation shall be defined to optimize data coverage based on pre-existing knowledge of seabed and morphology, geology and local environmental conditions. Tie lines to other known locations and geotechnical borehole sites shall be included in the survey line plan whenever possible.
For Category A and B locations, a surveyed area of minimum 300 x 300 meters square centered on the designated location can be accepted. Two line grids each consisting of a minimum of 7 lines, spaced at 50 meters intervals shall be acquired in orthogonal directions to cover the survey area. The centre lines of the line grids shall intersect at right angles at the designated location. The program of lines shall total (7+7) x 300= 4200 meters, excluding any necessary extensions to accommodate towed equipment or to enhance data interpretations. The grid may be modified in accordance with the characteristics of the equipment used and local site conditions; however deviations from the overall orthogonal grid pattern shall be avoided. The survey grid orientation shall be defined to optimize data coverage based on pre-existing knowledge of seabed and local environmental conditions.
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Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021 3.06.06
Version: 03
Bathymetric survey
The water depth shall be measured over the entire length of each grid line using a high precision echo sounder. The measured depths shall be reduced to the Lowest Astronomical Tide Datum. The tolerance for water depth measurements is 0.5 meters. Swathe bathymetry techniques should be used to survey rig access routes. 3.06.07
Seabed debris survey
Seabed surface surveys should be carried out using side scan sonar, Swathe bathymetry and high resolution echo sounder techniques. The survey should be such that it covers the immediate area around the location (1 km squared) and identifies seabed features and obstructions. The site survey should also include a magnetometer (this may be waived based on the type of side scan and echo sounder used) survey to identify objects below the mud line such as pipelines, wrecks and other metallic objects. Seabed surveys that are older than 6 months prior to rig emplacement should not be used. 3.06.08
Shallow seismic survey
This is required to provide the general near surface geological structure to identify reflectors which may represent changes in the soil characteristics. The data may also indicate any shallow gas within the vicinity of the location. The seismic equipment shall be able to provide detailed information to a minimum depth of 50 meters below the mud line or to the anticipated penetration + 2.5 times the spud can diameter. The report shall include at least 2 vertical cross sections passing through the location showing all relevant reflectors and any other pertinent information that will assist in carrying out analysis. The shallow seismic survey shall be interpreted by the competent persons who carried out the survey and every effort shall be made to comment on the types of soil and their strengths. This will require correlation with the results from the borehole / coring. Note: Seismic surveys alone are not normally sufficient to enable an analytical appraisal of the foundation with regards to predicted leg penetration. 3.06.09
Geotechnical investigations
These are site specific and required in areas where no soil data is available or where the foundation conditions are known to be hazardous. As a minimum at least one borehole should be made to a depth of 30 meters or to the anticipated leg penetration + 1.5 times the spud can diameter and as close to
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Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021
Version: 03
the centre of the leg pattern over the intended location as possible. The actual number of boreholes will depend on the nature of the soil. It should be noted, that the soil in certain areas can change within one leg centre displacement or less in which case soil boring (coring) under each spud can is required. For Category A, B and C Locations the minimum requirements for collecting geotechnical information shall be as follows: • •
• •
One CPT (Cone Penetration Test) at each leg location 1 (One) soil boring (coring) at a minimum distance of 2 meters (to avoid interference) and at a maximum distance of 5 meters from one of the CPTs. If none of the leg positions in question are appointed in advance, the coring contractor can select among them. Relevant laboratory tests to calibrate/define strength variations with depth. If soil conditions do not allow for the proper execution of one or more of the required CPTs, the CPT(s) in question shall be replaced by soil borings.
For Category D Locations and where no other geotechnical information is available one bore sample (coring) shall be taken under each spud can All layers should be investigated so that the properties of all layers are known with confidence and that there is no uncertainty in the formation record. The site investigation report should include but not be limited to the following: • Profile of undrained shear strength versus depth for cohesive soils • Effective stress strength parameters for cohesion-less soils • Piezocone penetration test (PCPT) records • Appropriate soil classification tests including Atterberg limits (clays), water contents, particle size distributions, unit weights, relative densities (sands) and Sensitivity (clays) • The over-consolidation ratio (OCR) for cohesive soils should be determined especially where foundation fixity is an issue. 3.06.10
Sampling and testing
The site investigation should comprise undisturbed soil sampling and/or Piezocone penetrometer testing or a combination of both.
3.06.11
Site investigation requirements
Review all known Geotechnical and Geophysical field data and compare with selfelevated Jack-up historical performance data (Desk Study). 3.06.12
Geophysical site survey requirements • •
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BATHYMETRY survey using echo sounder, tuned transducer & swathe techniques SEABED SURFACE SURVEY divers, side-scan sonar, ROV or scanning radar
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Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021 • • •
Version: 03
MAGNETOMETER SURVEY to identify metallic objects below the mud line SUB SURFACE / SHALLOW GAS SURVEY Pinger, Boomer, airgun etc. GRAB / CORE SAMPLING to assist with the geophysical analysis of the formation
ADDITIONAL SURVEYS FOR SPECIFIC LOCATIONS MAY BE REQUIRED AS FOLLOWS: • 3D SUB-SURFACE PROFILING • SINGLE OR MULTIPLE BOREHOLES Sufficient geotechnical and geophysical data shall be available to ensure a proper analysis can be carried out to ensure the safe emplacement and operation of the Jack-up. Site specific assessments may be required to be undertaken depending on the results of the foundation assessments and may require a reduced max preload value and Variable deck load value to enable the rig to be safely positioned on the location. This would require the assessment to meet the requirements of SNAME. 3.06.13
Requirements to individual subcontractors
Marine Warranty Surveyor A Surveyor representing a company approved by the Underwriters and which has been authorized by the COO of Seadrill to issue both the COLA for emplacement of the self-elevating drilling rig and verification documents (Towing Certificate, Tie Down Certificate etc.) on the accomplishment of intermediate stages of the operation. Geotechnical Contractor The approved contractor(s) shall be well recognized within the industry and be acceptable to the underwriters and MWS. The approved contractor(s) shall operate a formal quality management system, specifically encompassing seabed survey and/or soil investigation procedures, processing and reporting. The approved contractor’s quality management system(s) should have been audited and be accredited by a third party to international standards. The approved contractor’s documented procedures and records of competency assessment shall be available to the MWS and to Seadrill Corporate upon request. The surveys and investigations completed shall satisfy all legal, regulatory and statutory requirements in force in the area of operations. Site survey work will normally adhere to the current UKOOA Guidelines for the Conduct of Mobile Drilling Rig Site Surveys. (Volumes 1 and 2) These documents are to be supplied to all clients by Seadrill.
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Version: 03
Soil investigation work shall be conducted in accordance with current relevant ASTM and BSI procedures and codes of practice. Soil investigation assessments shall be made in accordance with SNAME (2nd edition JAN 2002) Bulletin 5-5A. Positioning services provided during surveys and soil investigations must, as a minimum, adhere to the current UKOOA Guidelines for the Use of Differential GPS in Offshore Surveying. Only contemporary equipment and methods shall be used during the surveys and investigations and during the analysis of results. These documents are to be supplied to all clients / Survey companies by Seadrill.
3.07
Load and stability calculations The following instruction has to be carried out using the onboard stability computer well in advance of the rig move date: • • •
•
•
3.08
The instructions contained in the Jack-up’s Marine Operations Manual for the particular type of rig move shall be strictly adhered to. The calculated maximum draft shall be within the limitations stated in the unit's Load Line Certificate. It should be checked that no load or stability limitations have been placed on the unit by local authorities, Classification Society, flag state or other authorized party. The OIM and Rig Mover should also be observant to any limitations recommended by the designated MWS, especially when extended field moves (greater then 12 hours) are taking place. Where closures are open and only have to be closed during bad weather conditions, special care should be taken to instruct the rig crew how and when these closures have to be secured.
Passage plan and navigational procedures A transit passage procedure shall be established and included in the site specific rig move procedure before commencement of a rig move. It shall be confirmed that the charts and nautical publications required for the planned voyage are of the latest revision and readily available. The route to be followed should be plotted and agreed upon with the Master(s) of the attending towing vessel(s), the MWS and the unit’s Senior Mariner during a meeting prior to the actual rig move. Attention should be given to any navigational hazards on the route and sufficient distance shall be maintained from offshore installations and pipelines. Where passage through safety zones enforced around installations is unavoidable, permission shall be obtained from the relevant authorities. The characteristics of the wind and current at time of being underway have to be taken into account when planning the route. Keeping a safe distance from the leeward coastline or shallow areas is one of the precautions that shall be taken.
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Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021
Version: 03
Short field moves where the Jack-up maintains an operational draft or the legs are not fully retracted should always be planned in such a way that a minimum clearance of 15 metres is assured to the seabed and from all subsea hazards. Such operations shall always be in accordance with the MOM. When planning extended field moves or ocean tows, it is necessary to take extra precautions when the route is chosen. The Jack-up should plan to maintain a route that permits pinning of the legs on the seabed within a 10 – 12 hours’ period. However, other extended periods can be planned where local conditions are such that agreement is reached with the involved parties, and detailed studies reveal that no imminent danger exists for the tow. When applicable, designated stand-by/ emergency location(s) will be identified in the passage plan and shall be surveyed according to the requirements of this manual. A listing of positions or ports that can be used as locations of refugee should be prepared and distributed to the Master(s) of the towing Vessels. Where the route necessitates the crossing of deep ocean where the rig cannot jack safely out of the water, these crossings should be made at an angle which minimizes the exposure time with due consideration of all other navigational risks. Attention shall be paid to local conditions e.g. confused sea states when navigating close to areas of extreme depth range or where strong tidal ripples may occur. Prior to departure the towing vessel(s) shall be informed about the draft and stability conditions of the Jack-up. Any significant changes in these conditions during the voyage shall, without delay, be passed on to the Master(s) on the towing Vessel(s). The navigational procedures during the voyage shall be discussed extensively and agreement made with the Master of the lead tug on the frequency and means of reporting positions to the Jack-up. When more than one vessel is engaged in the towing operation, the Rig Mover should always appoint one vessel as the lead tug and request the Master of this vessel to coordinate the navigation and manoeuvring of the towing vessels during the sea passage. The lead tug should preferably be the most capable vessel and be connected to the main towing bridle. The time or position when the Rig Mover transfers the safety of navigation to the Master of the lead tug, and the return of the same to the Rig Mover, shall be agreed upon and logged in the Rig Move Daily Log.
3.09
Securing for the tow The following instruction shall be carried out prior to commencement of the tow and shall be verified on a regular basis not exceeding 3 hours:
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Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021 •
•
•
•
•
•
•
•
• •
3.10
Version: 03
Equipment and material carried on deck should be limited to a minimum and arranged in such a way as that they do not interfere with safe passage for the crew and under no circumstances become a hindrance on the escape routes. Equipment and material above or below deck has to be sea fastened to the satisfaction of the attending Rig mover and Warranty Surveyor. The Rig Mover should generally refrain from accepting command of the unit before satisfied with the way that the unit is secured in every respect. Verification that the securing has taken place in accordance with instructions contained in the Operation Manual and other guidelines can be given by submittal of signed checklists and/or visual inspection by the Rig Mover and Warranty Surveyor. Sea-fastening should be designed to withstand the extreme motions which can be expected during the contemplated move period and has to include provision to withstand wave slam and buoyancy loads due to boarding sea. Special attention is required when items are placed at vulnerable positions near ventilators, tank air vents or hatch covers where breaking loose in heavy weather could have a hazardous impact on the water-tight or weather-tight integrity. Likewise a safe distance should be maintained to all life-saving and fire-fighting facilities in order not to hinder the rapid activation, should this be requested. Prior to a rig move a Certificate of Approval of the securing has to be obtained from the attending Warranty Surveyor and be readily available on board the unit. This Towing Certificate of Approval shall verify compliance with both the general requirements to securing and any pertaining requirements stipulated in a designated Towing Recommendation applicable for the operation. Spare securing equipment should be readily available on the unit. This is also to include welding equipment or cutting gear. Even if the MOM states that the rig is capable of carrying drill pipe in the derrick during an in field rig move, this shall be approved on a case by case basis. The duration of the move the expected weather conditions and the risk of punch through will be the deciding factors.
Towing gear The following guidelines cover technical and marine r eq u i r e m en t s t o t h e Ja c ku p ' s towing gear and its use. All equipment required for the passage or operation shall be confirmed fully functional and operational. General guidelines: • All towing gear like tow lines, tow line connection points, chain, bridle legs, bridle apex and shackles shall be certified by a 3rd party inspection company. • The equipment used shall correspond with the maximum bollard pull which can be obtained from the most capable attending towing
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Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021
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•
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• • • •
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vessel. However, in cases where very powerful vessels are involved it shall be ensured that the force applied will not exceed 50% of minimum breaking load (MBL) of the weakest part in the towing assembly. A maximum average working load at 1/3 of the MBL giving room for load peaks up to 50 % of MBL. The breaking load of the shackles used in the towing configuration should always be at least 10% above the breaking load of the towline in use. The breaking load of the weakest point in the towing configuration should never be less than twice the continuous certified bollard pull of the towing vessel. Towing connection points (Smitt Brackets) on the jack-up should be quick release type fittings. This to ensure that under extreme conditions clearing of fouled tow gear can take place. Chafing of wire pennants should be avoided, mainly by use of chain from the connecting point to the edge of the deck or past the fairleads. Where this is not possible other anti-chafing measures are to be taken. All towing pennants shall be equipped with hard eyes. Where towing bridles are used the angle at the apex should be within a range of 45-60 degrees. Emergency towing gear should have strength equal to the main towing arrangement. Arrangements have to be made for recovery of towing bridle or towing pennants.
Towing bridles shall be construed as follows: • The bridle leg should consist of either stud link chain or a combination of chain and wire rope. If the latter is used, the chain part should as a minimum reach from the connecting point beyond the deck edge to prevent chafing of the wire rope. • The end of all chains shall be equipped with enlarged links to fit into connecting points on deck and allow easy application of shackles. • The connection points on deck have to be of the Smitt-Bracket type. The bridle legs (chain or chain and wire) shall be connected to a Delta plate or towing ring. • An intermediate pennant wire can be attached to the delta plate or towing ring for easier handling when connecting the towing vessel. • This wire has to have a sufficient length to enable the vessel to connect or reconnect at safe manoeuvring distance from the hull. • The breaking strength of the intermediate pennant shall not be less than that of the main tow line. • The use of fuse wire or weak links is not recommended. However, if unavoidable due to local requirements the reduction on the fuse wire should never exceed 10% of the main tow line strength. • Synthetic springs shall not be accepted in connection with towing with the exception of harbour towing. • In order to obtain sufficient spring load the use of anchor chain length as weight is recommended.
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Field move guidelines: For field moves, which are defined as rig moves where the duration of towage is below 12 hours and no standby location is required or manoeuvring in restricted areas like harbours or on locations within a field, the same stringent guidelines and requirements need not necessarily be adhered to. Auxiliary towing vessels used for positioning and with restricted bollard pull can be accepted tied onto connecting points without quick release only if cutting gear is readily available in the vicinity. Extended field move guidelines: When rig moves categorised as extended field move, which is defined as rig moves where the duration of towage exceeds 12 hours and standby location(s) are required, are to take place, the requirements for ocean tow shallbe enforced. However, when weather information and the routing permits and the agreement is reached to reduce the requirements with the attending underwriter’s MWS, minor deviation from ocean tow requirements can be accepted. Ocean tow guidelines: • The main towing connection should always consist of a towing bridle arrangement installed at the bow of the unit. • There shall be an emergency towing bridle having the same strength as the main bridle. • Arrangements have to be made for recovery of both the main and the emergency towing arrangements. 3.10.01
Emergency towing gear
Emergency towing wires shall be installed in addition to the main tow bridle and shall be secured to the edge of the unit’s deck outside all obstructions for easy deployment in an emergency The securing shall be with soft lashings at sufficient intervals but not exceeding 3 meters, enabling release by strong pulling of a towing vessel. The emergency tow connection can be supplied with an extension wire long enough to ensure safe handling and avoid chafing. A messenger line should be attached and extended one unit length aft of the stern. A conspicuous plastic float should be attached and trailed.
3.11
Contingency plans and procedure The rig shall have a Contingency Plan consisting of a Station Bill covering relevant emergencies. The Station Bill will be supplemented by extra instructions, e.g. tropical cyclone/severe storm contingency or H2S Contingency Plans, whenever extraordinary circumstances warrant such. Local authorities generally require the Rig Operator to maintain an overall contingency plan for the area or units being utilized. In this case the unit’s contingency plan forms part of the Client’s Contingency Plan. This will generally be the case during contractual periods involving field moves and in rare cases extended field moves.
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It is the duty of the OIM to be conversant with the Client’s plans and to ensure that the rig crew and participating vessel crews are adhering to the contingency requirements. The crew participating in the rig move shall be instructed as to their duties prior to commencement of the rig move. The proper co-ordination of procedures between the vessels participating in the tow should be considered and agreed upon between the Masters, however, without interfering with the integrity of the Masters to act in an emergency as dictated by the relevant rules for vessels in distress.
3.12
Communication Jack-up’s are equipped with several means for both internal and external communication. Maintaining a radio link between the rig and the attending Vessels shall be confirmed prior to departure including primary and secondary methods. Communication links shall be maintained on a 24 hour basis. The primary link should be a marine VHF working channel. VHF channel 16 shall be monitored continuously. Agreed alternative links shall be maintained. These links may be provided by any other communication means available on all units concerned. If direct phone lines are not available, Satellite communication should be the primary media for contacts to shore and for data transmission. Where available and as a supplement to VHF communication, it may be practicable to utilize portable UHF radios. This can have the advantage of communication without interference where heavy traffic on VHF-channels is dominating. It is a good practice to establish a list of radio stations, which may be utilized by the participating vessels or by shore contacts in an emergency.
4.
OPERATION
4.01
Moving off location
4.01.01
General procedures
The general procedures for moving off location are influenced by several factors and require widely differing approaches, which cannot be covered in the Marine Operations Manual for the Jack-up. Upon completion of the preparation for the rig move it is the responsibility of the OIM to inform the relevant authorities and/or other involved parties about the intended rig move. Requirements that pertain to the area of operation can be extensive and it is recommended to coordinate the information that needs to be transmitted with both the local shore base and the Client's Representative.
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Confirmation that the attending vessels have been inspected by the MWS and approved fit for purpose are available, prepared and ready to commence the rig move should be verified. Acceptance by the MWS, is confirmed through a Certificate of Tow Approval (COTA) in connection with all rig moves including extended field moves or ocean tow/transport, as required by the underwriters. Any delays, caused by reasons which cannot be considered part of the moving off location procedure or which could give reason for dispute in relation to the contract or part of the contract, e.g. applicable rates, should be duly noted and reported either as part of the rig move report or, if deemed necessary, in separate documentation. 4.01.02
Jacking operation
Moving off location should only commence when the conditions are in compliance with the limitations stated in the Marine Operations Manual. However, jacking to a more convenient air gap waiting the final decision can be of advantage and is acceptable. If the air gap is reduced below the minimum requirements for the area and time of the year, it shall be possible to resume safe air gap within the time limit dictated by the advance warning system for excessive weather. Units equipped with leg clamping systems or other means of securing the legs in a fixed position can commence deactivating the system in preparation for jacking prior to completion of the securing, if approved by the OIM and subject to no extreme weather being imminent or anticipated for the rig move period. The period between jacked and afloat condition of a Jack-up should be kept to a minimum, as this is an especially vulnerable exposure position. Extra emphasis on reducing this period should be made where/when marginal conditions exist. Connecting of towing vessels should take place at a safe air gap meaning that the vessels are given the optimum conditions for manoeuvring without restrictions imposed by the hull and/or helicopter-deck. Prior to the Jack-up reaching the afloat condition (preferable when having reached a draft of 2-3 meters) the jacking should be halted and a thorough check of the water-tight closures will be conducted. Only if/when the water-tight integrity has been confirmed, the final jacking and leg retrieval should be attempted. The time of confirmation of the water-tight integrity shall be noted and reported in the rig move report. The retrieval of legs and spud cans can be achieved by jacking the hull to a draft in excess of the calculated displacement. The limitations allowed are stated in the Marine Operations Manual.
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04.01.03 Jetting When soil conditions and/or deep penetration restrict the timely retrieval or even keep the spud cans fixed, the high and low pressure jetting systems arranged on the spud can should be utilised. The freeing of one leg at a time can be of advantage as the water flow can be maintained at a higher capacity, however, caution should be exercised when this approach is used to avoid unnecessary strain in the leg or leg guides resulting from hull rotation when one leg breaks free. Guidance and information that could assist in evaluating the risk when using alternative methods should be tried obtained from any available source either locally or from the Seadrill Regional Office. When retrieving the legs a leg responsible person shall be sited at the leg well and in radio communications with the jacking control room to give immediate warning to the Jacking Control Room about any damages or hazards that can been seen. This could be loose pipes, damaged bracings or debris caught in the leg structure. In addition there shall be sufficient personnel for greasing the leg racks/ guides. Special attention should be paid to the accumulated soil on top of the spud cans when approaching the final stage of retrieval. Especially when deep penetration has been achieved in clay, the accumulated amount could become critical and result in damage to the hull. Close observation of power consumption or pressure indicators at the control stations can likewise indicate that a hazardous situation is under development. Accumulated soil on top of the spud cans can be washed off by utilising the high pressure system installed (top of spud cans) or by towing the legs in a partly lowered condition, subject to weather and sea conditions. The Rig Mover should advise the towing vessels of his decision and position of the legs/ spud cans enabling in safe navigation route due to excessive draft, reduced speed or drifting of the tow due to current or wind. 4.01.03
Use of towing vessels
Assisting vessels should be utilised to the extent possible to keep the unit in position during the leg retrieval. Where only one assisting vessel is available, the most convenient position should be chosen taking into account the wind, sea and current conditions during the period of time needed. During very short field moves the assisting vessel(s) can be kept in their position at the starboard or port quarter, however, if reconnection to assist at the bow is required, this should only be attempted at a safe distance from any obstructions in the area. During reconnection of the towing vessels the unit should be kept at a stable position without making headway.
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The towing vessel shall always be connected to the main bridle prior to attempting going into the water and retrieving legs. The vessel should be ready in position to pull as soon as the unit is afloat. When moving off platform installations the application of pull should be exercised prior to coming afloat to ensure that neither drift nor setting to the stern takes place; this is done to avoid any contact between the unit and the platform. When more than one vessel is used for towing, the most powerful or suitable vessel should be placed on the main bridle and be the lead tug. The towing vessels shall not commence towing at full power before the legs have been fully retrieved or the OIM/Rig mover has accepted this. The time period for going off location is considered completed when the unit is at a safe distance from location of departure and towing vessel(s) are connected ready for tow. The time will be noted as commencement of tow (start of Sea Passage). The time when sea passage is commenced should be logged on board the attending vessels as well with the clear understanding that the Master of the towing vessel or where more than one vessel is used the Master of the Lead Tug, has taken the full responsibility of the navigation in accordance with the applicable legislation. This includes coordination of the towing vessel's pull and change of heading and manoeuvring in compliance with the collision regulations. 4.01.04
Use of anchors
The use of anchors for moving the unit off location is not considered a standard requirement but can be advantageous where special circumstances warrant this or it is required by the Operator or attending MWS. The anchors shall always be secured in their anchor racks during field moves. In connection with extended field move extra securing with chain or wire together with quick release should be added. For ocean tow and upon request by the MWS for extended field move in adverse weather areas, the anchors should be double secured on the bolster to prevent movement or loss.
4.02
Transit The period to be considered as towing period will be the time from completion of going off location to commencement of the going on location time.
4.02.01
General procedure
During the towing period the OIM and Rig Mover shall ensure:
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• • • • • •
4.02.02
Version: 03
That the unit is towed and navigated safely and that the unit’s position, the weather and sea conditions are recorded at regular intervals. That the loading condition and stability criteria are maintained throughout the voyage. That rotation of a watch is established to perform and record water integrity checks. That necessary drills and exercises to maintain the crew ready and prepared for contingencies are held. That details and information concerning the voyage required by authorities or relevant entities is submitted. That proper seamanship is exercised in every respect. Insurers notified of commencement of tow and at completion of emplacement.
Watch keeping
Radio communication is maintained with the attending vessels 24 hours of each day. During the tow a sea watch, enabling an around-the-clock (24 hours) control of the safety and integrity of the unit, is maintained in all respects as dictated by regulations and proper seamanship. The duties of the engine watch will be to maintain the needed power supply and other necessities as dictated by the circumstances, and be prepared to respond to any emergency that might develop. The deck watch shall maintain communication with the attending vessels and establish a routine tour on the unit to check that the weather-tight integrity is maintained, that securing is maintained and that re-securing takes place should this be necessary. Observation of the navigational lights and signals are exhibited properly shall also form part of the tour. The towing gear shall, weather permitting, be inspected for chafing or other damage that could have an undesired impact on the safety of the established towing connection. The tour shall, as a minimum, take place at intervals of 2 hours. However, when deemed necessary by the OIM, a higher frequency should apply. The watch shall, during the tour, carry a portable radio enabling immediate contact with the control room. As part of the daily routines the Person in Charge or his delegate shall keep records of all occurrences or observations that could be of interest to the safety of the unit. This includes but is not limited to: • 2 hourly water tight integrity checks including checking /sounding all spaces/tanks/voids below deck. • Daily calculation of the water and fuel supplies.
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Daily updating on the stability to ensure that the unit remains within the limitation in accordance with the approved criteria. Any shortcomings observed shall if at all possible be corrected as soon as the situation permits.
Note: In certain areas the potential for activity by pirates warrants the use of extra personnel for the sea watch. This shall be included in the planning of the day-to-day work to ensure that excessive working hours are avoided and alertness is at the optimum at the most crucial hours. 4.02.03
Weather observations
The motion characteristics of the vessel shall be observed closely and where/when weather limitations are approached, corrective actions shall be taken e.g. by altering the heading of the tow or altering the pull exercised by the towing vessel(s) or altering length of tow wire. Should the unit be unable to maintain the motions within the values derived from the critical motion curves, steps shall be taken to minimize the danger for the crew and damages to the unit. The influence on tows by weather and the dangers of adverse conditions are wellknown and documented, thus the observation of weather and especially the changes compared to predictions can give trained observers early indication of potential upcoming risk. As a minimum, a record at intervals of 4 hours of the following shall be maintained during all rig moves: • Position and speed • Wind force • Wind direction • Sea height • Sea period • Swell height • Swell period • Barometric reading • Temperature • Cloud observation Actual weather shall be monitored and compared to the forecasted weather prior to the move to gauge the accuracy of the forecasted weather. The observation shall be compared with the forecast received from the weather bureaus and where development is in contradiction to the forecast, contact with the bureaus should be made for verification or clarification. Alternative weather forecasting sources can be sought to obtain further details. Whenever adverse weather (gale warning) is forecasted for the planned route, the frequency for observation shall be increased.
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When utilising special routing forecast, it is necessary to support the predictions by reporting the actual weather experienced. It shall thus be endeavoured to arrange for one daily submittal (noon observation) of the relevant observation to the routing service. Weather Forecaster shall be informed of the routing and advised of the tow’s position every 12 hours. Subtropical or tropical cyclones Whenever a situation requires, the rig move of a Jack-up through areas or during periods where these storms pose a risk, the special cyclone procedure adapted for the area shall be adhered to and arrangements with the routing forecast office shall reflect the increased risk. 4.02.04
Position reporting
Generally, all Jack-ups have equipment on board to determine the unit's position at any given time. During field rig moves in some parts of the world, the operator will provide position survey companies who, with their equipment and expertise, will assist the Rig Mover by providing exact information concerning the position, and other relevant navigational details, in order for the Jack-up to perform a safe transit from one location to the next. The navigational experience of the Rig Mover and visual observations, supplemented with survey companies’ and towing vessels’ information, will enable the Rig Mover to perform safe manoeuvring between locations. If the positioning equipment of the Jack-up fails for any reason, during an extended field move or ocean tow it is a requirement that the Rig Mover establishes the necessary routines to have the rigs position and any navigational information recorded by obtaining information from the towing vessel(s). The position of the tow shall be recorded at a minimum interval of four (4) hours, depending on transit area. The Marine Section Leader and Rig Mover shall ensure that the unit’s own navigational means are utilised to the greatest possible extent and any deviation observed, shall be brought to the attention of the Master(s) of the towing vessels and clarification obtained. During extended field move or ocean tow the daily position, together with other information, shall be forwarded to the shore base with copy to Seadrill Regional Office. Where Operators or local authorities require advice about the transit of Jackups either directly or through the local shore base, the OIM will ensure that data as requested is submitted either directly or through alternative routes. Even if such local reporting is not requested, it is advisable to report the intended move and frequent position to the local authorities that could have an interest,
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e.g. Rescue Centres, coastal radio or harbour authorities/Vessel Traffic Centres, especially where the approach is restricted. When under tow, navigational warnings (stating position, course, speed and total length of tow) shall be issued (preferably VHF transmittal). Warnings shall be issued with due consideration to the speed of the tow, surrounding traffic and circumstances which require special caution. When the tow is planned to pass through narrow straits, heavily congested traffic areas, traffic separation schemes etc., arrangements shall be made to issue navigational warnings on NAVTEX via marine rescue co-ordination centre (MRCC) or local maritime authorities in due time prior to the passage. 4.02.05
Crane operations
Crane operation during the rig move shall be limited to an absolute minimum, and, as a general rule, the cranes shall remain in the support structure secured against vertical or lateral movement. Any use of the cranes during a rig move has to be approved on a case-to-case basis by the OIM and a PTW issued. Where the situation permits the use of a crane, this shall be limited and the return to the support structure shall be executed immediately upon completion of the crane operation. For ocean tow and where required by the MWS’s recommendation for an extended field move, the cranes have to be secured to avoid revolving. When crane operation is required over the side during rig move, e.g. in case of personnel transfer (injuries) or if equipment has to be transferred from attending vessels, the Jack-up has to be stopped or kept into the wind without making headway. Attention to the dynamic forces and manoeuvrability of the vessel will always have to be evaluated carefully prior to any crane operation while under tow. 4.02.06
Minimum bunkers of diesel and portable water for passage
The Marine Section Leader shall ensure that adequate bunkers of diesel fuel and potable water are on board prior to the rig move. Bunkered volumes will take into consideration the number of personnel on board, the duration of the rig move, the possibility of the move being extended due to inclement weather or diverting to a stand by location or near by port of refuge and elevating the rig above the wave crests.
4.03
Going on location Going on Location, on completion of the sea passage the Rig Mover shall be responsible for manoeuvring the rig into final position by providing the tow vessels with detailed instructions on vessel headings and engine power to be applied.
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General procedures
Before commencing the final approach, certain items have to be checked or verified as follows: • Positioning equipment installed and confirmed operational. • Location marking confirmed placed in position as agreed for both location and obstructions. • Auxiliary vessels and/or assisting tow/ anchor handling vessel(s) in readiness. • Platform(s) advised of the approach and installation of the Jack-up and confirmation obtained that 'hot' platform(s) is (are) ready to shut-in if required. • Final approach to a platform shall normally commence during the hours of daylight. Final approach to platform during the hours of darkness can be allowed provided the following criteria are met: o The platform, its surroundings and the Jack-up are well lit providing adequate visibility to the rig move team (Rig Mover, Warranty Surveyor, Offshore Installation Manager and Barge Master) onboard during the final approach. o Positioning equipment to be verified to be fully functioning by the positioning surveyor and the rig move team when the rig is at the standoff position. o Anchor winches to be tested at the standoff position to verify they are in satisfactory condition prior departing from standoff position. o Should any adverse situation arise during the final approach to the platform, all operations will be stopped and the rig soft pinned until the situation is resolved. The Rig Move Team will then decide, depending on circumstances, to resume with the approach during darkness or wait till daylight. • Weather and sea conditions within limitation as stated in the Marine Operations Manual. • Acceptance from the Marine Warranty Surveyor is obtained for commencing the approach. • The crew of the Jack-up and other personnel are instructed about duties and advised about the operation. 4.03.02
Conditions on location
Whenever approaching the final location, whether an open sea location or a platform or other installation, the Rig Mover shall have in his possession the COLA issued by the appointed Marine Warranty Surveyor. The details contained in the same shall be checked and verified and particular attention shall be given to any recommendations or limitation incorporated in the approval. In case of vessels being observed within the exclusion zone (500 metres) of final location or in the approach channel, radio warning about the imminent approach shall be broadcasted with a request to clear the area.
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If available, a standby vessel could be dispatched well in advance and clear the area for the approach of the Jack-up. Verification of tidal or other current information shall be requested if available. A bridging document will be required detailing the requirements for simultaneous operations if other vessels are engaged in authorized operations within the location area (safety zone) or the anchor pattern. For normal supply vessel operations the supply vessel shall report in to the installation and request permission to enter the 500 metre exclusion zone. 4.03.03
Approach
The approach to a Wildcat Location should be made in a manner that maintained the rig’s heading in the direction of the prevailing weather. In certain cases, the operation of helicopters and supply vessels require that the rig is emplaced on a heading that is not in the direction of the prevailing weather. This is only acceptable when the rig’s stability remains within the limitations set out in the MOM. Prior to final approach to the location, the Rig Mover Shall ensure that there is sufficient power available, a spare generator should be on standby for immediate use. The tow should reduce the speed in time for the re-positioning of the towing vessel and the lowering of the legs. The crew shall be alerted in due time and a TBRA and tool box talk shall be performed involving all participants. Positioning equipment and jacking system shall be checked and confirmed in satisfactory operational conditions. The spud cans shall always be kept sufficiently above the seabed during the final approach within the surveyed area to ensure a minimum clearance of 5 meters above any seabed obstructions or to compensate for inaccuracy in the water depth expected. The legs shall only be lowered to 1.5 metres once the rig is within 100 metres of the location with minimal headway. The final lowering of the legs and engagement of the seabed with the spud cans shall preferably be executed with the unit making no/very limited headway. Where some headway is unavoidable, it shall preferably be ensured that the first bottom engagement is made by the two stern legs. Single leg touch down shall be avoided at all times. Furthermore this approach will minimize the change of the heading during the bottom engagement period. Even though the approach of a Wildcat Location generally does not require the greatest accuracy in positioning, it might be necessary to use anchors for the final and accurate positioning. The Seadrill Regional Office, Marine Section Leader and
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Rig Mover shall plan this in detail and take into account the number and size of the vessels available and other conditions like e.g. wind, sea, current and tidal parameters. Note: Approach of a Wildcat Location with one or even two vessels could necessitate the use of stern anchors for stopping headway or drifting off location. In these situations it could be of advantage to have an anchor ready and the anchor buoy trailing on the final approach. In general, positioning a Jack-up at platforms or re-entering subsea locations requires deployment of anchors for safe and accurate final positioning. The running of anchors will have to be planned in detail with all involved parties, taking into account the current situation and prevailing conditions, at the time of operation. As a general rule, the Jack-up should be pinned or positioned temporarily in an area approximately one rig length off the final location on a heading preferably close to the intended final true heading. In this position the Jack-up will run anchors, await the allowable weather conditions and, where required, await production shut-down and final approval for the approach. WARNING: Experience has shown that when a Jack-up is in transit from afloat to bottom supported condition, extreme gyrating of the hull may occur, especially where low but long swell exists. To avoid damage to both the unit and the installation from contact, the maximum safe distance with due consideration of drill floor reach of wells shall be attempted. Where only marginal distance can be maintained, it is advantageous to have a towing vessel connected and pulling away from the installation thus reducing the gyration. Also constant jacking of the legs shall be maintained to minimize the period of time where this phenomenon is apparent. It is the responsibility of the Operator's representative to accept the Final Position. 4.03.04
Anchor operations
The running of anchors shall take place based on a pre-agreed anchor pattern, which has the acceptance of the Operator and the Marine Warranty Surveyor. The anchor pattern shall, whenever possible, be laid in such a way that crossing of pipelines, cables or other subsea obstructions is avoided. If necessary, the maximum safe distance from such obstructions shall be obtained by means of spring buoys. Close attention shall be paid to the fact that the anchor handling vessel is maintaining sufficient pull to ensure vertical clearance of pipelines and cables while running anchor moorings.
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In case of interference with already established anchor patterns by another offshore unit, it shall be ensured that deployment of anchors does not interfere with the operation of the other unit. When running anchors only equipment used is equipment which has been checked and found to be in a good operational condition prior to use and the anchor wire or chain shall be examined for any damage such as broken wires or loose/missing studs in chain etc. If, due to the local circumstances, the exact positioning of anchors is of paramount importance, it is required to have the location marked by buoys or use highly accurate positioning equipment and Tug Management System. The Rig Mover and Marine Section Leader shall ensure that proper recording is kept on all anchor operations. The recording shall include position, distance and headings during deployment, thus making the search for equipment lost on the seabed, whether intentional or by mishap, as easy as possible. For the exact general pattern of deployment of anchors special mooring analyses that have been made for the area of operation shall be consulted. Either on request from the Operator or by other authorized parties. When a Jack-up has deployed the anchors, prior to going afloat for final positioning, the winches have to be pulled to stalling capacity and held for minimum 15 minutes to ensure that proper holding force has been obtained. If this is not the case, resetting of the anchors should be attempted with slight alteration of distance and/or heading. If this does not result in proper holding , the use of piggy-back anchors should be used. As an alternative and where piggy-back anchors are difficult to obtain, the use of towing vessels afloat or at anchor could, together with the unit's own anchor but at reduced holding capacity, give ample resistance to achieve a sufficient pull to move the Jack-up safely onto location. Note: Where pipelines and/or cables have been crossed with the anchors, dragging of anchors can result in costly legal proceedings if damage is claimed. It is thus a serious consequence if the Rig Mover and Marine Section Leader have failed to keep an accurate record of the circumstances around the anchor handling operation. Any observed discrepancy shall be noted in a Statement of Fact and signed by the Client Representative.
4.04
Preloading The Jack-up has to be preloaded to the minimum required seabed reaction as stated in the Marine Operations Manual and in accordance with the Certificate of Location Approval (COLA) and strictly in accordance with the site specific pre-load procedure issued by the Seadrill Regional Office. Preloading shall only commence when the final acceptance of the location has been received from the Client's representative.
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Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021
Version: 03
This preload shall be based on the year-round operational requirements, and only where special circumstances have been accepted prior to going on the location, a deviation will be incorporated in the location approval. The on board Marine Section Leader shall carry out a preload simulation and forward same to the Seadrill Regional office for approval. Preloading shall not commence unless there is a minimum weather window of 72 hours. As an alternative to the 72 hours requirement, a procedure for dumping the preload water and jacking up to safe height should be considered. Depending on the expected duration of the preload operation it may be necessary to have an even longer weather window or at least be in a position to have taken on sufficient preload to allow it to be dumped and the hull jacked above the wave crests to await the next suitable weather window to complete the preload operation. The default method of preloading shall be single leg with the hull in the water. Preload holding time will depend on the type of formation soil which is described in the foundation site assessment report. The minimum acceptable preload holding time is three (3) hours without any settlement. This may be reduced to 1 hour if previous experience of the area is known. Preloading shall take place with a minimum air gap, taking into account the tidal influences and the actual and expected weather criteria during the preload period. When an acceptable minimum air gap cannot be maintained, the Marine Section Leader and Marine Warranty Surveyor shall evaluate the overall situation and, if deemed necessary, abandon the operation and await improved conditions. If, due to weather conditions, a preload operation has to be abandoned, dump as much preload as possible and jack the unit to a height which ensures that the waves will not reach the bottom of the hull. The unit shall thus maintain alertness to any change in the weather and be prepared to adjust on short or immediate notice to any development in the wave action. The preload shall preferably be taken on board in an uninterrupted sequence to avoid thixotropic effect (building a crust). This effect has relevance in soil of clay or clay nature and shall be considered a high risk for punch-through. If the above effect is allowed to develop, it can become necessary to abandon the location or reposition the unit on a virgin soil. Preload shall be taken on board in a pre-planned sequence ensuring equal distribution on the legs. It is recommended to prepare a written instruction based on the approved simulation of the preload operation. When the Jack-up is positioned close to a platform and where a potential risk of punch-through or rapid penetration is apparent, extra care shall be exercised
Doc. Owner: H. M. Hansen Printed date: 18/08/2011
Approved by: Per Wullf
Approved 18.08.2011 Page 43 of 45
Risk level:
Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021
Version: 03
when taking onboard preload water. In this context it is advisable to give the forward leg a slight head load, thus forcing the unit to heel towards the bow, should unequal or rapid penetration occur. When a Jack-up is positioned close to a platform single leg preloading shall be adopted. The single leg preloading shall start with the bow leg followed by the stern legs. This will reduce the risk of contact between unit and platform and minimize possible damage.
4.05
Special soil conditions In special situations, e.g. when knowledge concerning soil gives reason to believe that rapid penetration or even punch-through is a risk, it is acceptable after consultation with the Marine Warranty Surveyor to carry out sequential (leg-by-leg) preload at draft. However, sequential preload at various drafts ending up with preload at air gap will be covered under these special soil conditions – In this respect the periods of holding the preload at each step shall be no less than 3 hours and the final simultaneous preload at minimum air gap shall be no less than 6 hours.
4.06
Jacking to final air gap After completion of the preloading and a satisfactory result of the settlement period have been recorded, the preload water shall be dumped before commencing the final jacking to the minimum required air gap as stipulated in the location approval. It shall be verified that lifeboat/raft wires and raw water towers have sufficient length at extreme operating air gaps. During final jacking the Marine Section Leader shall ensure that the raw water supply system is under strict surveillance by a responsible supervisor equipped with a communication means to the jacking control room for immediate alarm to stop jacking. This is necessary in order to avoid damage to the piping or cables in the raw water supply system. The air gap can be adjusted to a higher figure to achieve improved stress distribution by placing bracing or connecting points in or close to the leg guides. Likewise, it is permitted to adjust to a higher air gap for fixed installation levels or conductor pipe measurements. The final position of the Jack-up, however, shall never exceed the approved maximum allowable air gap. The required leg reserve of (1.5 metres) shall not be used without the explicit approval from the Seadrill Regional Office and the attending MWS. During jacking the hull shall be kept at an even level, but as a minimum within the allowable 0.3 degree where even level is not achievable.
Doc. Owner: H. M. Hansen Printed date: 18/08/2011
Approved by: Per Wullf
Approved 18.08.2011 Page 44 of 45
Risk level:
Rig Move Manual
Title: Jack-up rig move – general requirements Doc. No: DIR-37-0021
Version: 03
When reaching the final air gap, the hull shall always be placed at an even level and the level alarm (if available) should be checked and left in operational position. The final air gap shall be confirmed and accepted by the Client Representative and the time recorded. Final measurements of the leg position and “rack phase differentials” shall be carried out and noted in the Rig Move log book and report. At final air gap and during the drilling operation, monitoring for gas bubbles and hull elevation shall be carried out on a daily basis. On completion of preloading all preload water shall be dumped from the preload tanks by either opening the docking plugs or by means of pumping the tanks dry. If for any reason this is not possible then the weight remaining on board shall be verified and included in the daily calculations for the units VDL. On completion of dumping preload all dump valves and docking plugs shall be closed.
4.07
Clamping and skidding of derrick For units equipped with leg clamping system, clamping of the legs and load shifting shall be carried out prior to skidding out the cantilever.
5.
REPORTING AND FORMS
5.01
Checklists .01 .02 .03
5.02
Pre-jacking Rig move Post jacking
Templates .01 .02 .03 .04 .05 .06
Rig move procedure Preload procedure End of rig move report Daily positioning reports during tow Rig move log book Final position record
Doc. Owner: H. M. Hansen Printed date: 18/08/2011
Approved by: Per Wullf
Approved 18.08.2011 Page 45 of 45
