The Threaded Style Back

The threaded style Back-Pressure Valve (BPV) and Two-Way Check Valves (TWCV) combine internal running threads, external setting threads and an internal stinger. The type ‘H’ BPV is designed to hold pressure from the wellbore, or below, only. Cameron rates these BPV’s at 20,000 psi. They have an internal, female, right hand running thread that mates with the running, or retrieving tool, and an external, male, left-hand ACME setting thread that mates with the tubing hanger. Please refer to Figure 2E-15, below. The internal plunger consists of a valve and spring assembly that will seal and hold pressure from below. When offset this plunger, see Figure 2E-16, allows pressure to by-pass and equalize above and below the BPV. This plunger also allows fluid to be pumped through the BPV in the event that it is necessary to pump kill fluid into the well with the plug installed. The external external seal is a lip type seal on the O.D. of the BPV. This seal is energized when the plug is rotated into the mating profile in the tubing tu bing hanger. The type ‘H’ BPV should not be overtightened. Over-tightening Over-tightening this type of plug will not help it seal, but can make it hard to remove. Figure4.4 Figure4.4 Running Procedures for Type ‘H’ Plugs Before Starting: Thoroughly clean the plug with solvent. Inspect the lip seal, replace if damaged or cut. Inspect the running threads and setting threads for damage. Inspect the plunger and spring to ensure that they are not damaged. If possible set the plug in the hanger (before the hanger is installed). 4.4.1 Method 1: Installation using the Retrieving/Running Tool (Figure 2E-19) A) Measure Measure from the the lock-screws lock-screws on the top flange flange of the the tubing spool to the top of the tree connection (if installing through a tree), or to the drill floor (if installing through BOPE). To this dimension add 18 to 36 inches. This is the length of polished rod required. B) Assemble the polish rod and attach the Retrieving/Running tool to the bottom piece. C) Thread the plug onto the Retrieving/Running tool (8 to 8-1/2 rounds) rounds) and tighten with two 18” pipe wrenches. The connection should be tight enough that when threading the plug into the hanger it will not break out before it is seated. D) Coat the plug threads and lip seal with an even application of never-seize.

SAUDI ARAMCO WORKO WORKOVER VER M ANU AL Drilling & Workover Engineering Department May 1999 CHAPTER 2 WORKOVER PRACTICES SECTION E WELLHEADS ____________________________________________________ ________________________ _________________________________________________________ _________________________________________________________ __________________________________________ ______________

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E) Lower the assembly through the tree, or BOP, and stab plug into the hanger. F) Turn to the right one turn to align the threads. G) Turn to the left 4 to 6 rounds until the rod becomes hard to turn. This is the break-over point and indicates that the plug has seated. H) With an 18” pipe wrench, continue to rotate the rod to the left until

they become easy to turn. This indicates that the Running/Retrieving tool is now backing out of the plug I) Continue to turn 8 to 10 rounds to completely disengage the Running/Retrieving tool. J) Remove the rod assembly from the tree, or BOP. 4.4.2 Method 2: Installation using the Running Tool (Figure 2E-20) A) Measure from the lock-screws on the top flange of the tubing spool to the top of the tree connection (if installing through a tree), or to the drill floor (if installing through BOPE). To this dimension add 18 to 36 inches. This is the length of polished rod required. B) Assemble the polish rod and attach the Running tool to the bottom piece. C) Thread the plug onto the Running tool and make it up until it bottoms out, no torque is required. D) Coat the plug threads and lip seal with an even application of never-seize. E) Lower the assembly through the tree, or BOP, and stab plug into the hanger. F) Turn to the right one turn to align the threads. Watch for the rod to drop about ½ inch; this indicates that the torque pin has engaged the slot on the top of the plug. G) Turn to the left 4 to 6 rounds until the rod becomes hard to turn. This is the break-over point and indicates that the plug has seated. H) With an 18” pipe wrench, continue to rotate the rods to the left until a maximum of 50 ft lbs. has been applied. Under no circumstances should the plug be over-tightened. I) Pick up the rod about ½ inch and continue to turn to the left to thread the running tool out of the plug. J) Continue to turn 8 to 10 rounds to completely disengage the Running tool. K) Remove the rod assembly from the tree, or BOP.

SAUDI ARAMCO WORKOVER M ANU AL Drilling & Workover Engineering Department May 1999 CHAPTER 2 WORKOVER PRACTICES SECTION E WELLHEADS ___________________________________________________________________________________________________________________________

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5.0 RE-STUBBING CASING: Many of the older Arab-D producers and Power Water Injection (PWI) wells require ‘re-stubbing’ because of internal/external corrosion of the exposed and uncemented casing near surface. This re-stubbing operation includes: Digging out around the wellhead until good 13-3/8” is located. Cutting off the 13-3/8” and 9-5/8” casing (if required) Welding new 13-3/8” and 9-5/8” casing sections back to surface. Installing a new/reconditioned landing base on the 13- 3/8” casing. Landing the 9-5/8” casing with slips in the landing base. Installing new/reconditioned spool(s) and tree. 5.1 Typical Re-Stubbing Procedure for Arab-D Producers Required Isolation Barriers: (2) Mechanical (1) Non-Mechanical

Tubing removal procedure can vary with specific well completion. A) Move in and rig up workover rig. Check/report all wellhead pressures. Bleed off annuli pressures. Dig out around the wellhead and check landing base for corrosion and proper support. Mark/report wellhead and valve operators orientation. Flare gas off tubing and TCA, if any. PT TCA to 1000 psi. Kill well by bullheading kill weight NaCl brine down the tubing. B) RU SAWL. NU/PT lubricator to 2000 psi. Set 3½" PX plug in X nipple (ID 2.75") and PT to 1000 psi. Open 3½" SSD or punch 3½" tubing. RD SAWL. Circulate tubing and TCA with kill weight brine. Set BPV in tubing hanger. Observe and assure that the well is dead and hole is full. ND tree, NU BOPE and PT to 200/2000 psi. Retrieve BPV. C) Unsting from packer and circulate hole with kill weight brine. If seals are stuck, cut tubing above packer. POH and LD tubing. Inspect and report condition of tubing, seal assembly and all nipples. D) RIH with 9-5/8", 36# casing scraper to +1500’ and POH. RIH with 9 -5/8” RBP. Set RBP at +1400’ and PT to 1000 psi. ND BOPE and Tubing Spool.


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Re-stubbing procedure is listed below. A) Cut off 13? " casing right below landing base. B) Dig around 13? " casing until good casing is found. Cut off the landing base and corroded section of 13? " casing. Clean 9? " casing from cement and inspect for corrosion. C) Re-stub cut-off casing(s) and fill the annulus with Class G neat cement slurry. D) Weld new 13? " × 13? " × 2" × 2", 3M Landing Base on 13? " casing. Stab 9-5/8” Casing Spear and engage casing. Land 9? " casing with mechanical slips inside landing base. Re-completion procedure can vary with specific well requirements. A) Dress 9-5/8” casing stub. NU new/reconditioned 13? " x 13? " Casing Spool with new bushing. PO and PT 9- 5/8” bushing to 1000 psi. B) NU new/reconditioned 13? " × 11" × 2" × 2", 3M Tubing Spool. NU BOPE . C) PT 9? " × 13?" annulus to 500 psi with inhibited water with 1% B-1400. If injection is established, fill the annulus with Class G + 2% CaCl2. RIH with cup tester. PT BOPE and wellhead to 200 and 2000 psi with water. Flush annulus valves with fresh water after cementing. D) RIH and retrieve the 9-5/8” RBP. E) Rerun/replace downhole completion equipment as required. F) ND BOPE. G) NU new/reconditioned 11” x 4-½” Tubing Bonnet and 4-½” Tree. H) Report the serial number all new/reconditioned wellhead equipment installed. I) Report the length of casing stub(s), sizes and types of flanges and spools.

SAUDI ARAMCO WORKOVER M ANU AL

Drilling & Workover Engineering Department May 1999 CHAPTER 2 WORKOVER PRACTICES SECTION E WELLHEADS ___________________________________________________________________________________________________________________________

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5.2 Typical Re-Stubbing Procedure for PWI Wells Required Isolation Barriers: (2) Mechanical (1) Non-Mechanical Note: 2 nd Mechanical Barrier is required if oil and gas is present on flow back. Preparation procedure can vary with specific casing program. A) Move in and rig up workover rig. Check/report all wellhead pressures. Bleed off annuli pressures. Dig out around the wellhead and check landing base for corrosion and proper support. Mark/report wellhead and valve operators orientation. Flow well to pit and check for oil and gas. Close 10” Ball Valve and ensure valve is holding well pressure. Reopen Ball Valve B) Kill well by bullheading kill weight CaCl2 brine down the 9-5/8” casing. Observe well is dead. Close 10” Ball Valve and ND Injection Tree. NU BOPE on top of Ball Valve , pumping brine down the wellbore while nippling up. PT to 300/3000 psi. C) RIH with 7", 23# casing scraper to + 6500’ and POH. RIH with 7” EZSV BP. Set EZSV at + 6400’ and PT to 3000 p si. If PT fails, establish injection rate and locate leaks with RTTS. D) RIH with 9-5/8", 36# casing scraper to +1500’ and POH. RIH with 9 -5/8” RBP. Set RBP at +1400’ and PT to 1000 psi. ND BOPE and 10” Ball Valve. Re-stubbing procedure is listed below. A) Cut off 13? " casing right below landing base. B) Dig around 13? " casing until good casing is found. Cut off the landing base and corroded part of 13? " casing. Clean 9? " casing from cement and inspect for corrosion. C) Re-stub cut-off casing(s) and fill the annulus with Class G ‘Neat’ cement slurry. D) Weld new 13? " × 13? " × 2" × 2", 3M Landing Base on 13? " casing. Stab 9-5/8” Casing Spear and engage casing. Land 9? " casing with mechanical slips inside landing base.


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Re-completion procedure can vary with specific well requirements. A) Dress 9-5/8” casing stub. NU new/reconditioned 13? " x 13? " Casing Spool with new bushing. PO and PT 9- 5/8” bushing to 1000 psi. B) NU BOPE. C) PT 9? " × 13?" annulus to 500 psi with inhibited water with 1% B-1400. If injection is established, fill the annulus with Class G + 2% CaCl2. RIH with cup tester. PT BOPE and wellhead to 300 and 3000 psi with water. Flush annulus valves with fresh water after cementing. D) RIH and retrieve the 9-5/8” RBP. E) RIH with mill. Mill out 7” EZSV BP at + 6400’. POH and LD DP.

F) Close Ball Valve. ND BOPE. G) NU new/reconditioned Injection Tree. H) Bullhead casing with + 60 bbls fresh water. Flow back for clean up. Run sinker bar and report fill. I) Report the serial number all new/reconditioned wellhead equipment installed. J) Report the length of casing stub(s), sizes and types of flanges and spools.

SAUDI ARAMCO WORKOVER M ANU AL Drilling & Workover Engineering Department May 1999 CHAPTER 2 WORKOVER PRACTICES SECTION F LOST CIRCULATION __________________________________________________________________________________________________________________________

LOST CIRCULA TION 1.0 INTRODUCTION 2.0 CONVENTIONAL LOSS CIRCULATION MATERIAL 2.1 Characteristics 2.2 Procedures

3.0 ACID SOLUBLE GROUND MARBLE 3.1 Characteristics 3.1.1 Selection of CaCO3 Particle Size Basis 3.1.2 Typical CaCO3 Pill Formulation 3.1.3 Average Properties of CaCO 3 Carrier Fluid 3.2 Recommended Procedures

4.0 GUNK PLUG 4.1 Characteristics 4.2 Procedures

5.0 POLYMER PLUG 5.1 5.2 5.3 5.4 5.5

Types of Polymer Plugs Flo-Chek Temblok-100 High Temperature Blocking Gel Protectozone

6.0 BARITE PLUG 6.1 Characteristics 6.2 Slurry Volume Calculations 6.3 Pilot Testing 6.4 Pumping, Displacement Rates and Equipment 6.5 Procedures

7.0 THIXOTROPIC CEMENT 7.1 Characteristics 7.2 Procedures

8.0 CEMENT PLUG 8.1 Characteristics and Precautions 8.2 Procedures

9.0 FOAM CEMENT 9.1 Characteristics 9.2 Procedures


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LOST CIRCULA TION 1.0 INTRODUCTION 1.1 Loss of circulation occurs when the formation drilled is extremely permeable and a pressure differential is applied toward the formation. The mud loss rate dramatically increases by the excessive overbalance pressures created by the hydrostatic head of the column of mud in the hole. In some cases, decreasing the differential pressure by reducing the fluid density and pumping rate or pressure will stop fluid losses and regain circulation. However, the most effective method for combating lost circulation is to reduce the permeability of the borehole wall by introducing properly sized bridging material, commonly known as loss circulation material (LCM) into the rock pores with a high viscosity pills. Bridging particles contained in the mud will not seal the zone if they are smaller than the formation pores. Potential loss of circulation zones usually encountered in Saudi Aramco’s fields include Pre-Neogene Unconformity (PNU) Umm Er Redhuma (UER) M a jo r l o s s e s Wasia Formation Shuaiba Major losses Arab-D Reservoir M a jo r l o s s e s Hanifa Reservoir Lower Fadhili Resrevoir Haurania Zone Major losses Below the base of the Jilh dolomite 1.2 Loss circulation material (LCM) is normally added to the circulating drilling mud, or in a high viscosity pill to be spotted across the lost circulation zone. The LCM includes, but is not limited to A) Conventional bridging agents; Fibrous Material ........................................... Cedar Fiber Flake Material .............................................. Mica coarse and fine Cellophane Granular Material ......................................... Walnut shells Cotton seed hulls


The Threaded Style Back

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