METHOD STATEMENT OF PIPELINE PIGGING SERVICES
POLMAZ LIMITED
INTRODUCTION
This report covers pipeline operation (routine) pigging for pipeline maintenance as is the practice in modern pipeline operations. This technical report can also be made a procedure document providing clearly defined and structured guidelines for safe and efficient operations during pipeline pigging and related activities on all liquid, gas ga s pipelines to minimize risk and negative impact upon client’s facilities and the environment. WHAT IS A’ PIG’?
Pigs are devices, hich are inserted into, and travel throughout the length of a pipeline, during the product flo. They fall into to categories! "#T$%$T&’ P$' hich perform a function such as cleaning, separating or deatering the pipeline, and inline inspection or more simply, "$%$ T**%’ (sometimes referred to as "intelligent pigs’ or "smart pigs,) + hich provide information on the condition of the lines as ell as the etent and location of any problems. WHY PIG A PIPELINE
- pipeline is arguably the most efficient method yet devised for transporting fluidshether gases or liquids. $ts relative’s efficiency though depends upon to fundamental requirements! a) b)
$t must ust oper perate con continuously and The required throughput must be obtained ith the least capital investment and the loest operating costs.
Pigs play a ma/or role in both obtaining and maintenance the "to fundamentals’. fund amentals’. 0.
They They hel help to to ens ensur uree con conttinuo inuous us oper operat atio ion n by by! remo removi ving ng any any sub subst stan ance ce hi hich ch migh mightt dam damag agee the the pip pipel elin inee proc proces esss sy system stems s hel helping ping to pre preve vent nt the form ormati ation of cor corrosio osion n cel cellls prov proviiding ding ti timely mely infor nform mati ation of of any any deve devellopin oping g prob probllems ems prov provid idin ing g data data on on any any perc percei eive ved d prob proble lems ms to ena enabl blee info inform rmed ed dec decis isio ions ns to to be 1ade prov provid idin ing g an alt alter erna nati tive ve to to shut shutti ting ng do don n for for sta statu tuto tory ry per perio iodi dicc test testin ing. g.
2.
They They hel help to ensu ensurre maim aimum um eff efficien ciency cy by! by!
rem removi oving any any debr debriis or for foreign eign matte atterr in the the line ne remo removi ving ng any depos deposit its, s, eith either er liqui liquid d or or sol sold, d, hic hich h mig might ht othe other ris isee bui build ld up and restrict the flo monitoring the operating and3or physical conditions of the line.
PIPELINE PIGGABILITY
POLMAZ LIMITED
PROGRESSIVE PIGGING
Pipelines that have never been pigged or have not been pigged for some time may have substantially reduced bores due to build up of deposits3debris. These deposits may consist of sand, corrosion products, a and3or scale. The progressive pigging operation under high flo conditions (above 0m3s) should consist of three (4) steps! (a) To ensure that there are no ma/or obstructions one (0) or (2) soft (foam) pigs should be run. (b) To check piggability, a cup ith open bypass ports and gauging plate should be run (c) To fully dislodge and suspend the debris, bidi pigs ith open bypass ports should be run $f hard scale is present in a pipeline, then studded foam pigs should be used. RECOMMENDED ROUTINE MAINTENANCE PIGS Foam Pig
%east aggressive of all pig types, 5oam pigs are normally used for providing, batching or sabbing. $t is a pig made of open cell polyurethane foam. $t is available in variety of foam densities to suit various applications. $t is available ith polyurethane coating for added durability and also available ith ire brush mats for more aggressive cleaning qualities. Basi S!a"#! Pig
-n industry standard coming in a variety of forms, they are unidirectional and are propelled by conical polyurethane cups, hich tend to ride over debris in the pipeline. pringloaded ire brushes improve cleaning ability. Bi$Di!#%io&a' Pig (Bi$Di)
This type of Piggs are an industry standard ith improved qualities over foam and scrapper pigs. They are versatile pigs, hich can be used for the removal of loose debris, soft a and liquid batching in pipelines. They are bidirectional and are propelled by discs that are efficient at removing debris from the pipeline. They are available ith spider nose bypass facility to reduce risk of the line blockage due to debris accumulation.
POLMAZ LIMITED
I&%#''ig#&% Pig
They are electro magnetically 3 ultrasonic coded tools (pigs) hich provide information on the condition of the pipeline internal as ell as the etent and location of any problems. 6ence, they confirm the pipeline status and integrity. Pig T!a*i&g
- technique used to monitor a pig moving through a pipeline. $n the event that the pig becomes immobilized due to restrictions in the pipeline, or periodic tracking is required, using a pig tracker hich is a transponder capable emitting a signal, and shall be fastened securely to the pig prior to launching. This signal is readily identified from a hand held detector from above ground. WOR+ PRACTICE (R#,#! %o %-# a%%a-#. "ig ,'o/ -a!% a&. sim"'i,i#. "ig %!a") PRE$LAUNCH ACTIVITIES
5or all routine maintenance pigging using approved cleaning pigs and ith velocity not less than 7.8m3s, 879 of the available bypass ports shall be left opened. 6oever, for cases of here the velocity is less than 7.8m3s, all bypassed ports shall be closed to ensure sufficient pressure differential is maintained across the p ig. -ll solid body pigs shall be fitted ith a pig tracking3locating device3transmitter ensuring that batteries are sufficiently charged for the entire run duration. Pigging facilities at both ends shall be inspected and certified suited for safe pigging operations. -ny threat or unsafe condition observed to the pigging operations shall result in suspension of pigging. -ll intermediate pipeline valves including river crossing ball valves shall be checked to ensure that they are in fully open position. $n the event that any intermediate valve is struck in partially closed position, the pig launch shall be suspended until the affected valve is repaired. There shall be diesel transfer pumps, vacuum trucks and trucks3environmental barges of adequate capacity for liquid handling prior to lineup of pig receiver. $t shall be ensured that for delivery lines, the producing flo station as not shut don ithin the last 2: hrs and that for all cases there is enough production to provide the minimum specified fluid velocity required to drive the pig to the receiver. ;o pig shall be launched if it ill not be recovered prior to any planned shut, don of station.
POLMAZ LIMITED
-vailability of functional communication system beteen the ork site and base shall be ensured, in the event of emergency. PIG RECEIVER BARREL LINE$UP
There shall be calibrated and functional pressure gauges ith enough range to cover the maimum alloable operating pressure (1-*P) of the pipeline to be pigged. The gauges shall have a current test certificate. $t shall be verified that no unsafe conditions eist that could affect the 6< aspects of the operation. erify that drain lines are free from blockage. >erify that the vent valves (<) are fully closed ithout leaks. 'radually crack open the kicker line valve (?) to pressurize the barrel using the vent >alve (<) to vent all trapped gas3air. The vent valves (<) shall be closed once all gas3air has been vented from the trap. The barrel shall be fully pressurized hen the pressure gauges on the barrel and mainline are reading same valves. 5ully open kicker line valve (?) and main line valve (=) ?lose the bypass valve (-) to @89 closed position to cater for backpressure in the event of high debris buildup in the barrel. PIG LAUNCHING
5or manifold over ater, a mini boom shall be deployed around the barrel and saver pit areas. ?ertified pressure gauges shall be installed on each side of the barrel isolation valve (=) the gauges shall be such that the epected orking pressure falls approimately mid ay on the gauge range. ?onnect a pressure recorder to the pipeline such that pressure3time may be monitored throughout the travel time of the pig. The range of the recorder shall be such that the epected orking pressure falls approimately mid ay on the recorder range. 5ully open the bypass valve (-) =oth mainline valve (=) and kicker line (?) shall be in fully closed position. 'radually open the drain valve (A)
POLMAZ LIMITED
The vent valves (<) shall be gradually opened to depressurise the barrel hile the drain valve (A) shall be used to completely drain the launcher into the drain pit. ?onfirm that the barrel pressure is zero using the gauge on the launcher barrel prior to gradual and sequential opening of the launcher door (5). Test pit + tracking equipment to ensure proper orking conditions eist. $f the pig cannot be manually loaded safely, load the approved pig into the barrel using the lifting facility provided on the manifold. %oad the approved pit into the barrel ensuring that the pig nose is in front and the front drive cup in contact ith the reducer section of the launcher barrel. (- push rod or ram is to be used to position pigs in long barrels) ?lose the barrel door (5) taking care not to damage the door seal and secure all locking devices tightly. ?lose the drain valve (A) 'radually crack open the kicker line valve ( ?) to fill the barrel ith the liquid hile leaving the vent valve (<) open to displace the air in the launcher barrel until all the air is displaced. ?losed the vent valve (<) and fully pressure gauges on both the launcher barrel using the kicker line valve (? ) and mainline indicate the same reading. 'radually open the main line valve (=) until it is fully opened. 1ain both kicker line valve (?) and mainline valve (=) in fully open position. 'radually closed the bypass valve (-) to direct fluid flo through the launcher barrel until the pig signalers turn to indicate pig travel out of the launcher barrel through the above ground pipeline section into the underground section. Beset both signalers Beturn the launcher barrel to normal operating made by opening the bypass valve (-) close the kicker line valve (?) and close the mainline valve (=) in the sequence indicated. Aepressurise and drain the launcher barrel by opening the drain valve (A) follo by the vent valve (<) in sequence. Cero pressure in the barrel shall be confirmed using the pressure gauge and the end closure safety bleed device prior to opening of the barrel door.
POLMAZ LIMITED *pen the barrel door (5) to confirm that pigs ere actually launched. ?heck the door seal for damages replace the seal if damaged or grease it if in good condition. ?lose the barrel door (5) the drain (A) and vent valve (<) properly.
Arain pit shall be evacuated and aste disposed of safety. PIG RECOVERY
Dhen the pig arrival is confirmed in the receiver by the operation of the pig signalers and3or the pig tracker, the recovery procedure shall be activated.
POLMAZ LIMITED
$nspect the recovered pig for possible damage, record any observation and return to base for appropriate action. ENVIRONMENTAL 0 WASTE HANDLING
$t shall be ensured that the environmental impact of pigging operation is not neglected. -ll activities shall be performed such that liquid and solid astes are treated according to the guidelines set out belo. WASTE HANDLING AND DISPOSAL
-ll liquid aste shall be drained from the barrel via the drain line into the manifold saver pit. There shall be adequate haulage in the savour pit overfloing. Transfer of liquid aste from the barrel to the savour pit shall be accomplished ith moderate pressure such that splashing does not occu r. The savour pit shall completely evacuated before leaving site. -t locations not having an automated recovery system, all liquid aste shall either be collected in suitable atertight sealable containers, collected by vacuum tanker or rein/ected into the pipeline sing purpose built diesel drum pumps. *n no account shall separated ater be evacuated into the environment. *nly suitable hand or diesel driven pumps shall be used for the transfer of saver pit aste. Aecanting from buckets is not encouraged. There shall be absorbent materials for mopping up operations in the event of a minor spill. -ll solid aste shall be collected, categorized and eighed on site. These shall be evacuated to approved and licensed facility. ENVIRONMENTAL CONTIGENCY
Auring all pigging operations, contingencies for the unepected release of product into the environment shall be put in place. 5or all samp operations a boom shall be deployed such that the entire ater surface around the pigging platform is encompassed.
POLMAZ LIMITED -bsorbent materials shall be readily available to remove any traces of oil failing onto the ater surface from the platform.
-ny traces of product shall be cleaned from the manifold structure on completion of operations using absorbent material. PIPELINE PIGGABILITY
Prior to commencement of a pigging operation, it must be ensued that there are no pipeline features that ould impede the travel of the pig. 5or the entire pipeline system route that a pig ill travel (i.e. launcher to receiver), the folloing physical aspects should be checked before the pigging is approved. These checks should be conducted before the pig is ordered, so that the information can be passed on the pig supplier and suitable pigs can be obtained. Pipeline 5eature Dhat to ?heck for $nternal diameter of the The internal diameter should be checked to ensure that the folloing features! pig selected ill be able to pass through. Pigs should be able to traverse the folloings (sub/ect to confirmation by G 5langes supplier)! G Tees G =ends G =idi pigs + up to 079 of nominal $A G >alves G ?up pigs + up to 089 nominal $A G Biser H topsides piping G 5oam pigs + up to 279 nominal $A up to pig trap G =idi cast pigs + up to 089 of nominal $A G Beducers G ?up cast pigs + up to 279 of nominal $A G ;arro pig trap barrels Aesign of tees
5or spheres, sphere tees should be installed 5or other pig types, barred tees should be installed for branch sizes larger than 879 of nominal line size. 1ost conventional pigs can transverse branch sizes up to @79, and intelligent pigs, sizes up to E79.
Aesign of valves
'ate and ball valve on the pipeline should not have bores smaller than I79 of the nominal line size.
1itred bends
1itred bends should have angles of no more than si degrees
*pening of valves
The correct setting of end stoppers shall be checked to ensure that valves are fully opened for the pig runs. -ny valves not fully opened may damage both pig and valve.
Pipelines coating
ith
internal Pigs ith ire brushes may damage internal coating.
%auncher lengths
and
receiver %engths of the launcher and receiver barrels POLMAZ should LIMITED be checked to ensure they are adequate, especially in the case of intelligent pigs.
ROUTINE PIGGING ACTIVIITES
The internal of the candidate pipelines ill be cleaned on monthly routine basis. This ill include pipelines ranging from J inches. *ccasionally, provisions shall be made for the cleaning of pipelines ith gas or crude oil medium for line sizes of :F, EF and :JF hen the need arises. 5or the routine pigging of pipelines, the under listed pigs ill be used. (a) 5orm Pig (b) craper Pig (c) =idirectional Pig The 5orm Pig ill be used to pig lines that have not been pigged for a long time or lines in hich hard scales eist. This ill reduce the changes of stuck pig in the line. 5orm pig is used as a compromise here scraper or =idi pigs cannot be used in the first run. craper Pigs are mandrel pigs ith conical cups and blades or brushes, they perform better than foam pigs in removal of debris from pipelines but they are not as aggressive as bidi pigs. Pipeline that are not descaled are pigged ith scraper and or foam pigs. They only move in one direction hence they are unidirectional. =iAi pigs are most efficient and preferred pigs for pigging of ne or descaled pipeline. - bidi pig comprises of a mandrel ith guide and sealing discs. They are very aggressive in ith bypass nozzles for /etting debris aay from the front of the pig.
GENERAL PROVISION PERSONNEL
1obile 6ouse =oat Bamp =arges Tug =oats ?rane 27 tons Pig Trackers Pigs Personnel, etc.
OF
WOR+
SUPPORT
E1UIPMENT0TOOL0
POLMAZ LIMITED
Boutine Pigging of pipelines and pig maintenance -uiliary pumping of lo flo pipelines >alve greasing 3 maintenance 'reasing 3 stroking of manually operated valves (1*>) $nspecting 3 reports of shallo creeks Beporting of sabotage of client facilities pill containment + drums, ater, pumps, buckets, boats, canoe, shovels, pickup car and Personnel
P!#mo2i'isa%io& ν ν ν ν ν ν ν ν
-rrangement of the base etting up a miniorkshop for the cleaning of pigs and related equipment Procurement of hand tools and bo Procurement of personal protective equipment and 2 first aid boes ?onfirming the date of inspection from ?%$<;T Aefinitions of the various personnel involved 3 organization 5ield /ob reporting formats and activities updates afely training of the technical cre
Mo2i'i3a%io& ν ν ν
electing the actual leasers and inspecting their units before client inspection *rientation of the upervisor 3 foremen on facilities inspection and data gathering 'rouping of the cells for the ork proper