1 Introduction and Requirements

1.1 Objectives

To replace the leaking completion tubing in oil producer.

1.2 Documentation

1.3 Account Number and Timing

The account number for the workover operation is ___

Operations are expected to commence ____

1.4 Communication

1.5 Reporting

2 Preparation and Background Information

2.1 Background

2.2 Well Data

  • Current production performance ___ m3/day at ___ bar CITHP
  • 'A' annulus pressure during injection xxx bar
  • Reservoir pressure/ temperature
  • Maximum well deviation ___ deg @ __ ft ahbdf
  • Deviation across reservoir __ deg.
  • Perforation intervals ____ ft ahbdf

2.3 Kill Fluid

The kill fluid to be used will be Brine ( ordered at ___ pptf ).

The latest estimate of the reservoir pressure in the area is ___ psi @ ___ ft TVSS.

The reservoir temperature is ___ deg F at this depth.

Pressure at top perforations at ___ ft AHBDF (___ TVBDF) is ___ psi.

Gradient to balance __ psi/ft

100 psi Safety factor ___ psi/ft

4.5% average decrease in density due to temperature effects

Required Brine Gradient ___ pptf

Note this brine gradient is a calculation for ordering purposes. The final gradient will be established after sbhp survey prior to workover

3 Pre Workover Operations

3.1 Important Depths

  • WRSSSV 1,986 ft AHBDF
  • Baker 4.313" Nipple 9,606 ft AHBDF
  • Top of ELTSR Housing 9,609 ft AHBDF
  • Top of 9 5/8" Baker DAB Packer 9,647 ft AHBDF
  • Baker 4.000" AF Nipple 9,677 ft AHBDF
  • Top of 7" PBR 9,688 ft AHBDF
  • 7" Liner Hanger 9,718 ff AHBDF
  • Top Perforation 10,677 ft AHBDF

3.2 Well Kill

3.2.1 Prior to the start of the operations, check annular and tubing pressures and report on the DOR. Soak the tubing hanger tie down bolts in penetrating oil.

3.2.2 Line up cement unit to 'A' Annulus. Kill the well by simultaneously pumping down the tubing and the annulus with brine ( with a determined gradient ).

The tubing volume to the perforations is 258 bbls and the annular volume is 384 bbls. Total volume is 642 bbls.

Monitor well for 2 hours to confirm well is dead, ie fully 'topped up' with zero pressure on the gauges.

3.2.3 Rig up wireline. RIH and pull WRSSSV and set big bore dummy. Test control and balance lines.

3.2.4 RIH and set 4" AF plug and prong in 4" AF nipple at 9677 ft ahbdf. Pressure test plug to 2500 psi ( based upon 9 5/8" leak off gradient with 515 pptf brine in the hole). Ensure 'B' annulus is bled off and open during pressure testing. Record volume pumped. This will test :

  • 4" plug,
  • Packer,
  • Hanger seals.

Bleed off pressure and inflow test plug, liner lap, packer and annulus for 2 hours.

If it not possible to set the plug, or to obtain a good test , run in and set a 4.313" AF plug and prong in the 4.313" AF nipple at 9606 ft ahbdf. Test the plug and prong as above.

3.2.5 Check the integrity of the 7" tubing hanger GS seals and MTM seals by testing to 3,000 psi via the tubing spool test port. Record volume pumped.

Rig up chicksans, to 'A' annulus and pressure test in leak off mode to 1500 psi. Ensure 'B' annulus is bled off and open during test.

3.2.6 Install a 7" PES plug below the hanger. Pressure test the plug to 5000 psi from above and 1500 psi from below ( through tubing leak) via 'A' annulus. Record volumes pumped. This will test:

  • 4" plug,
  • Packer,
  • Hanger seals
  • 7" plug.

3.2.6 Ensure the BOP is pressure tested on stub prior to nippling up.

4 Preparation

4.1 Ensure 'A' , 'B' and 'C' annuli are reading zero pressure and all wellhead/ hanger cavities are zero prior to nippling down Xmas tree. Nipple down and remove the Xmas tree. Check the condition of the thread for pulling the hanger and tubing. If the thread is in poor condition a spear will be used

Ensure the balance and control lines are isolated, in order to prevent pressure bleed off during testing the BOP's.

Check the condition of the tie-down bolts, if in poor condition, change out tie down bolts one at a time.

4.2 At this stage the well barriers in place are:

· 'A' Annulus

· Pressure testedpacke and plug to 1500 psi

· Tubing hanger seals pressure tested to 3,000 psi from above and 1500 psi from below.

· Brine bullheaded to the perforations, well flow checked.

· Tubing

· Deep set bridge plug pressure tested to 2500 psi and inflow tested.

· PES bridge plug set below hanger pressure tested to 5000 psi from above and 1500 psi below through tubing leak.

· Brine bullheaded to the perforations, well flow checked.

4.3 Install 13 5/8", 5,000 psi x 13 5/8", 10,000 psi adapter flange ( L191532), riser and 13-5/8" 5000 psi BOP with rams as follows (from top):

  • Annular
  • Variable bore rams (4 1/2" - 7")
  • Blind rams
  • Variable bore rams (2 7/8" - 5")

Note: Choke and kill lines below blind rams.

4.4 Install a chiksan line from one of the 'A' annulus outlets to a BOP side outlet ( to allow fluid to bypass the hanger when circulating or lowering /pulling the hanger ). Ensure that the chiksan line is tested when the BOP's are tested. Close wellhead valve as soon, as it is no longer required.

4.5 RIH with 5" drillpipe, test tool and crossover. Make up into the tubing hanger threads. If the hanger threads are corroded or are damaged, it will not be possible to make up the crossover tool.

Test lower rams, chicksan loop and adapter flange connection (against closed valve) to 3000 psi. Remove test string. Test blind rams to 3000 psi against PES plug. Monitor volumes pumped.

Run a drift through the BOP stack to ensure clear passage for pulling tubing hanger/seal assembly.

4.6 RIH and retrieve 7" PES plug.

4.7 RIH and retrieve 4" prong and plug body ( or 4.313" plug and prong ).

4.8 Observe well. If losses are obseved bullhead a viscous blocking pill, ie HEC polymer down the tubing. Observe well until stable.

5 Tubulars Removal

5.1 RIH 7" landing joint and engage with the hanger threads (chain tong tight), count the number of turns. Alternatively, depending on the condition of the hanger threads, RIH with 7" casing spear and packoff. Back-out hanger tie-down bolts fully to permit pulling the hanger.

5.2 Unseat the tubing hanger and pick up tubing such that the ELTSR is clear of the extenda joint. Note on the DOR any overpull observed.

NOTE:The calculated weight of the existing completion string 200 klbs. DO NOT EXCEED 150 KLBS OVERPULL. If the string cannot be pulled free, inform the Santa Fe Operations Engineer.

5.3 Pull and lay down the tubing. Observe closely for overpulls which may indicate the loss of control line clamps. Maintain tension on the control line while pulling to give an indication of control line integrity.

Record the number of control line clamps recovered on the DOR. ( 146 clamps - 3 per joint - were recorded for the existing completion ).

Number all the joints sequentially with waterproof paint as they are pulled. Inspect visually and report tubing condition. Any joints with obvious defects should be bundled separately and noted in the DOR .

Completion assemblies are to be bundled seperately

Monitor for LSA scale as per guidelines.

Ensure that an adequate number of protectors are on site.

The offshore well site engineer is to compile a report on the condition of the pulled tubular. Refer to appx 5 for the original tubing tally.

6 WELL BORE CLEAN-UP

IMPORTANT: The success of item 6.4 will determine whether or not the top workover programme is to be cancelled for the full workover.

6.1 Install wear bushing.

6.2 Make up original ELTSR housing (with all seals removed ) 9 5/8" scraper cleanout BHA and RIH on 5" drillpipe to 9,600 ft.

6.3 Circulate the well to clean brine. Be prepared to circulate via production facilities in case there is a crude cap beneath the hanger in the annulus.

Ensure the well is circulated clean as possible by using viscous pill until the solids content reads 0.05% or less. If after 3 circulations it appears the solids content will not reach 0.05% but the graph has flattened out, do not keep circulating unnecessarily

6.4 Carefully lower the ELTSR over the slick joint whilst circulating at a low rate. Accurately establish and record the depth when the ELTSR housing is bottoming out on the slick joint.

NOTE : If the ELTSR does not go over the slick joint, inform the Ops Engineer. The programme will continue from section 8 (full workover ).

6.5 Scrape interval 9,550 - 9,600 ft ahbdf (twice) and circulate well clean with viscous pill and brine.

6.6 POOH and lay out BHA.

7 Completion Running

7.1 Completion running for top workover only

General Requirements:-

(a) Refer to Procedures for general preparation of sub-assemblies, handling and running of tubing, recommended torque and pressure testing.

(b) Wireline BOP must be pressure tested, if possible on test stump, before start up. If not already done, perform pressure testing during rig-up.

(c) Install and test a chicksan loop from the cementing manifold to one of the BOP side outlets to perform all annulus pressure tests.

(d) Prepare the tubing hanger as follows, if not already done at the well services workshop: Install tubing hanger running tool on a tubing joint. Clean and lubricate the tubing hanger threads and the running tool pin thread. Make up the running tool into the tubing hanger hand tight. Clean and inspect, protect the seal area and lay back the assembly.

(e) Sufficient pup joints to be onboard to position packer between collars or space out if incorrect amount of compression is encountered after setting the packer.

(f) Wellservices supervisor to ensure accurate drawings are made of all assemblies. AOWE, Santa Fe Drilling Engineer and WSS to check and agree content of well status diagram.

Completion sub assemblies ( for Top workover only ) :

Assembly 1A:

Assembly 2A:

Assembly 3A:

NOTE:

1) The SABL-3 packer should be fitted with 3 annealed steel shear screws giving a pressure of 800-1200 psi to activate the packer slips.

2) Use a tubing clamp as the weight of the sub-assemblies is insufficient to be held by the slips.

3) Run the tubing and sub-assemblies at a uniform rate. Stop tubing slowly with the brake without jerking before setting the slips.

4) Appropriate fishing tools for the packer and slick joint should be on site.

7.1.1 Pick up and make up the tailpipe sub-assemblies and land off as low as possible in the rotary table. Rig up wireline and run the prong in the 3.688" nipple. Test the tail pipe/packer assembly to 5000 psi for 15 minutes. Clear the rigfloor dring testing. Remove packer test segments and clamp. Pull the prong from the 3.688" AF Nipple.

7.1.2 Pick up the anchor latch and nipple assembly. Stab the anchor seal and latch into the seal bore above the packer and make up wrench tight (LH thread). Back off the anchor ¼ turn after make up as per manufacturer's instructions.

7.1.3 Run an additional joint of 5 1/2" 23 lbs/ft tubing and land off as low as possible in the slips.

Rig up wireline and pull the 3.688 AF plug body as a drift run.

The plug and prong will be re-run prior to setting the packer ( this enables circulation in case of well control problems ).

7.1.4 Run 5 1/2" tubing as required.

Note : the 5 1/2" 23 lbs/ft tubing will be run above the packer up to the TRSSSV.

7.1.5 Install 5 1/2" 23 lbs/ft x 5 1/2" 17 lbs/ft x-over ( assy x). Ensure proper make up torque is applied.

7.1.6 Install TRSSSV assembly without isolation sleeve installed, and one joint of 17 lbs/ft tubiing ( report TRSSSV number on the DOR ).

7.1.7 Connect control line to TRSSSV and pressure test to 7500 psi. Check visually to ensure the valve is fully open. Reduce the pressure to 3000 psi.

7.1.8 Continue running 5 1/2" 17 lbs/ft tubing. Install 2 off control line protectors per joint while running, one to be across coupling, and one mid-joint.

NOTE: Take care when putting in the slips that the control line is not crimped.

Record the total number of protectors run. These quantities should be recorded on the DOR, included on the final well status diagram and in the individual well file.

NOTE: 5 1/2" 17 lbs/ft 13Cr tubing will be run from the TRSSSV to the hanger.

7.1.9 Perform a 4" drift run through the TRSSSV.

7.1.10 Run the 5 1/2" 17 lbs/ft tubing to one joint below the hanger.

Prior to picking up the hanger, check the number of joints remaining on the deck is correct and agrees with the running list.

NOTE: The tubing hanger and running tool will have been prepared in the Well Services Workshop and sent offshore in the completion skip.

7.1.11 Prior to swallowing the slick joint note up and down weights.

7.1.12 Pick up one joint of 5 1/2" tubing, install circulating head. Carefully lower completion over slick joint whilst circulating at a low rate. Accurately establish and record the depth when the ELTSR housing is bottoming out on the slick joint.

7.1.13 The completion should be spaced out in such a way that the packer is not set across a coupling and that the ELTSR housing is +/- 8 ft from the bottom of the slick joint. Ref appx 6 for 9 5/8" casing tally.

The completion is set in neutral so space out should be such that when the hanger is landed off the packer is at packer setting depth.

7.2 Installing Tubing Hanger

7.2.1 The tubing hanger and running tool will have been prepared in the Well Services Workshop and sent offshore in the completion skip. Check dimensions of the tubing hanger. The Cameron CS1 WKI 2 stage manual TPD 4051 should be studied prior to running the hanger and a Cameron engineer should be on site for the space out and hang off operations. Ensure that Cameron container has been called out in time.

7.2.2 Remove the circulating head.

7.2.3 Install hanger and pup joint assembly (assy #x ) on the last joint as per the running tally, (ensure that the tie down bolts are fully retracted).

7.2.4 Bleed off the control line pressure. Cut and terminate the control line. Dress the control line through the hanger as per GUIDEX prcedures. Grease the hanger seal ring, OD and tie down shoulder. Connect a suitable length of control line to the top of the hanger outlet and open the TRSSSV.

7.2.5 Pick up and install the landing joint.

7.2.6 Lower the completion slowly and land off the tubing hanger. Monitor landing of the hanger through the spool side outlets. The groove machined in the lower hanger neck should line up with the outlet center. Mark the landing string at the rotary table.

7.2.7 Report on the DOR the final static string weight. Land off the string carefully.

7.2.8 With the hanger fully landed, make up the upper tie-down bolts, tighten sequentially using the ratchet wrench. Do not apply excessive force at this stage, aim more to initially squeeze the seal, with all tie-down screws taking equal load.

7.2.9 Hook up to the side outlet on the water injection spool and pressure test the 7.5/8" x 5" tubing annulus to 3,500psi for 15 minutes. This will test the G-22 seals and tubing hanger. Throughout the test, the tubing should remain open. In addition, ensure that the test port between the hanger seals is open (should fluid be seen to be leaking from this port, then it can be concluded that the hanger seals are leaking).

Bleed off the test pressure and drain the BOP / riser via the by-pass from the injection spool outlet. Establish the base annular flow (gallons / hour).

7.2.10 Install the pressure test equipment in one upper test port of the spool and a pressure releasing tool in the diametrically opposite test port. This is in preparation for testing the hanger body seals, but will be used initially to determine if pressure applied above the top seal, to assist seal energisation, is blowing past the seal. Ensure side outlet below hanger is open during the following tests.

Close the rams around the tubing landing string and pressurise above the hanger to 1500psi. With the check valve of the test port unseated, ensure that the applied pressure is not leaking past the seal. If leakage is seen, reduce the pressure until the leakage stops. With the pressure above maintained, again tighten the tie-down screws in sequence, this time using the torque wrench, in 50 ftlbs increments up to a value of 400 ftlbs.

Apply 3,000psi, maximum, above the hanger, and again tighten the tie-down screws, in sequence, (50 ftlbs increments) to a maximum of 600 ftlbs. Bleed off pressure above hanger.

With the test port check valve still unseated, apply test pressure through the opposite port, until air has been fully flushed from the system. Close the the port check valve and build up pressure, in stages, to 5,000psi.

If the required pressure in not achieved, release the test pressure and again pressure up above the hanger to 3,000psi. Re-tighten the tie-down screws to 700 ftlbs. Bleed off the pressure above the hanger and re-test the hanger seals.

Bleed off test pressure

7.2.11 Pressure test to 3500 psi between the seals of the tubing hanger by applying pressure at the test port. Observe for returns at the 'A' annulus outlet.

NOTE: Ensure the test fittings and check valves are removed from wellhead test ports. Chicksan loop open. Do not rely on stinger tools.

7.2.12 Rig up slickline complete with surface pressure control equipment and two auxiliary swab valves below a pump-in T piece on top of the landing joint. Run the 4.313" AFH plug and prong and set 4.313" AF nipple. Note the setting depth and check against tally. Pressure test the completion and both auxiliary swab valves seperately to 5000 psi. Close the TRSSSV, bleed off above and inflow test the TRSSSV. Equalise and open the SSSV. Pull the 4.313" AF plug and prong..

7.2.13 RIH and set the 3.688" AFH prong in the 3.688" AFH plug body ( below the new packer ).

7.3 Setting Packer

NOTE: Ensure that ther is no further movement of the completion with the prong installed. Movement of the completion upwards with the plug/prong installed may result in the packer setting due to forces exerted while lifting the fluid column above the plug.

7.3.1 Obtain base annular flow at the "A" annulus side outlet. Slowly increase pressure continuously to 4,000 psi ( 3,000 + diff.pressure ) to set the packer. Closely observe pressure build up, checking volumes pumped to ensure the prong is not leaking.

Fully energise the seal element with 4000 psi, maintain this pressure for 15 minutes. Note the volumes pumped and monitor the casing spool side outlets for returns.

If, required, repeat the above process to verify that the seals have energised.

7.3.2 Pick up to 20 klbs above string upweight to confirm anchor latch and packer slips are set.

7.3.3 Pressure test the complation to 5000 psi. This is the final tubing pressure test. Bleed down the pressure to 1000 psi ( pressure differential ) .

7.3.4 Test the "A" annulus via the side outlets (in leak off mode) to 1500 psi for 15 minutes stable ( ensure the annular bypass is open ).

7.3.5 Bleed off any tubing head pressure ( 1000 psi or pressure differential ) and inflow test the 3.688" AF plug and prong for 2 hours.

7.3.6 Install TWCV in the 7" tubing hanger and pressure test to 5000 psi. Bleed off the control line pressure to close TRSSSV.

7.3.7 Remove the BOP stack and riser having first ensured that the Xmas tree is ready for installation.

At this stage the well control lines of defence are:

  • Annulus
  • Packer pressure tested to 1500 psi from above.
  • Hanger seals pressure tested 3500 psi from above and 1500 psi from below.
  • Annulus filled with xxx brine.
  • Tubing
  • Deep set plug tested to 5000 psi and inflow tested for 2 hours.
  • TWCV installed and pressure tested 5000 psi from above

Additional

  • Closed and inflow tested TRSSSV.

7.4 Installing Tubing Bonnet

7.4.1 Install and Test WKM (Cooper) Tubing Bonnet.

7.4.2 Clean and inspect the BX-157 ring grooves in the unihead spool and the tubing hanger and clean and inspect the sealing surface. Check the condition of the GS seals on the tubing hanger extended neck.

Install a new BX-157 ring gasket in the unihead spool. Remove the adhesive tape securing the control lines and straighten part of the control lines, leaving at least one full turn wrapped around the recessed portion of the hanger neck.

7.4.3 Install a new 7" nominal DT seal in the tubing hanger neck. Lightly coat the seal sub with anti-scuffing paste and also apply the lubricant to the GS seals and the tubing hanger extended neck.

7.4.4 Pick up the tubing bonnet by means of the two lifting eyes provided and carefully lower it over the tubing hanger neck.

7.4.5 Make up the 13 5/8" 5000 psi flange nuts, taking care to tighten down the connection evenly. The final gap between the flange faces should be virtually zero (in any event less than 0.020").

Note: Ensure that the test port in the tubing bonnet is open when lowering over the DT seal sub to avoid pressure lock.

7.4.6 Pressure test the DT seal sub by applying pressure at the upper test port in the tubing bonnet. Test to 5000 psi for 15 minutes.

Pressure test the control line to 7500 psi.

7.4.7 Install the test equipment in the tubing bonnet lower test port and displace the air from the void by pumping fluid until it overflows from the control line exit port.

7.4.8 Install the specially modified Swagelok fittings in the 3/8" NPT control line tapping. Tighten down the ferrule nut to seal off the control line.

NOTE: Only fittings of the same material as the line should be used ( ie Monel 400 or Incoloy 825 ).

7.4.9 Ensure that the tubing bonnet upper test port is open. Apply a test pressure of 5000 psi for 15 minutes at the tubing bonnet lower test port.

7.4.10 On achieving a satisfactory test, remove the test equipment from the tubing bonnet lower test port and bleed all test pressure from the port, allow the test fluid to drain from the void space.

7.4.11 Cut off the control line approximately 1/2" above the ferrule nut of the Swagelok fitting. Clean the BX 151 ring groove and install the BX 151 ring gasket. Install a dual needle valve block on the control line exit, ensure that the flange is pulled down evenly by the four cap screws. It is recommended that the needle valve block be installed on the tubing bonnet such that the caps for the needle valve are pointing downwards. In this position the entry of dirt into the valve will be precluded and convenient access to operate the valve will be made.

7.4.12 To test the BX 151 flanged connection, install the test equipment in the 1/2" NPT port of the needle valve block. Ensure that the lower test port of the tubing bonnet is open and that both needle valves in the block are open. Apply 5000 psi test pressure and hold for 15 minutes.

7.4.13 On completion, remove the test equipment and ensure that bleed fittings are correctly installed in all the tubing bonnet and unitised head ports.

7.5 Installing Xmas Tree & Re-instatement

NOTE: Ref. Cameron Running Procedure Wellhead Manual TPD 4051.

7.5.1 Clean the BX-157 ring grooves and the sealing surfaces for the DT seal sub. Lightly coat the DT seal sub with anti-scuffing paste and install it in the wellhead.

7.5.2 Pick up the solid block Xmas tree and lower it over the DT seal sub down onto the tubing bonnet.

Note: Ensure that the orientation of the Xmas tree is correct for attachment of the flowline.

7.5.3 Make up the CIW clamp until the gap between the clamp hub faces is less than 0.020".

7.5.4 Install test equipment in the test port in the base of the Xmas tree and pressure test the connection to 5000 psi for 15 minutes.

7.5.5 On completion of the test, bleed all pressure from the test ports, remove the test equipment and ensure that all check valves are installed and sealed and that bleeder plugs are installed in all Xmas tree ports and tubing bonnet.

7.5.6 Hook up flow line.

7.5.7 Pressure test the Xmas tree body to 5000 psi against the TWCV in the tubing hanger. Monitor the volume pumped closely.

7.5.8 Pull the TWCV valve.

7.5.9 Rig up wireline and test wireline pressure equipment. Pull and retrieve deep set 3.688" AFH plug and prong from tailpipe.

7.5.10 Hand well over to Production.

** end of top workover programme **

8 Contingency procedures for full workover

The following procedures are to be followed in the event that during the clean out run, the ELTSR outer housing is unable to swallow the slick joint.

8.1 Retrieval of Slick joint/packer and tailpipe

8.1.1 POOH with cleanout BHA. Lay out old ELTSR housing.

8.1.2 Make-up and RIH with the slick joint retrieval assembly to 9,400 ft ahbdf. Verify depths with tally ( appx 5 ) for spacing out. RIH carefully to 9,600 ft ahbdf.

Latch on slickjoint at +/- 9,609 ft ahbdf and apply 5-10 klbs overpull. Rotate K22 latch free. POOH.

8.1.3 Make-up and RIH with a packer-picker assembly to 9,400 ft ahbdf. Verify depth with tally ( appx 5 ) for space out for milling operations. RIH carefully to 9,640 ft ahbdf.

8.1.4 Mill packer at 9,647 ft. Once packer has been milled, observe well. If losses are observed bullhead a viscous blocking pill with no solids, i.e; HEC polymer down to the perforations.

8.1.5 Pull seal mandrel from 7" PBR at 9,688 ft ahbdf and observe well. If losses are observed bullhead a viscous blocking pill with no solids, i.e; HEC polymer down to the perforations. POOH with packer and tailpipe assembly as per GUIDEX.

Losses should be 10 bbls/hr or below before POOH with packer.

8.2 Well Cleanout

8.2.1 Make-up and RIH with a clean-up assembly ( string/taper mill, 9-5/8" scraper). Assembly is to be spaced out such that the string mill will be in th PBR with the Scraper at the new packer setting depth at +/- 9,640' ( 8 ft above 7" PBR ).

8.2.2 Dress off PBR whilst scraping interval 9,650 - 9,600 ft ahbdf (twice). Circulate well clean with viscous pill and brine.

8.2.3 POOH and lay out BHA. Report condition of mill in DOR.

8.3 Completion Running for FULL WORKOVER ONLY

General Requirements:-

(a) Ref: Completion/Tubing Procedures for general preparation of sub-assemblies, handling and running of tubing, recommended torque and pressure testing.

(b) Wireline BOP must be pressure tested, if possible on test stump, before start up. If not already done, perform pressure testing during rig-up.

(c) Install and test a chicksan loop from the cementing manifold to one of the BOP side outlets to perform all annulus pressure tests.

(d) Prepare the tubing hanger as follows, if not already done at the well services workshop:

Install tubing hanger running tool on a tubing joint. Clean and lubricate the tubing hanger threads and the running tool pin thread. Make up the running tool into the tubing hanger hand tight. Clean and inspect, protect the seal area and lay back the assembly.

(e) Sufficient pup joints to be onboard to position packer between collars or space out if incorrect amount of compression is encountered after setting the packer.

(f) Wellservices supervisor to ensure accurate drawings are made of all assemblies.

Completion sub assemblies ( for Full workover only ) :

Assembly 1B:

Assembly 2B:

Assembly 3B:

NOTE:

1) The SABL-3 packer should be fitted with 3 annealed steel shear screws giving a pressure of 800-1200 psi to activate the packer slips.

2) Use a tubing clamp as the weight of the sub-assemblies is insufficient to be held by the slips.

3) Run the tubing and sub-assemblies at a uniform rate. Stop tubing slowly with the brake without jerking before setting the slips.

4) Appropriate fishing tools for the packer and slick joint should be on site.

8.3.1 Pick up and make up the tailpipe sub-assemblies and land off as low as possible in the rotary table. Rig up wireline and run the prong in the 3.688" nipple. Test the tail pipe/packer assembly to 5000 psi for 15 minutes. Clear the rigfloor dring testing. Remove packer test segments and clamp. Pull the prong from the 3.688" AF Nipple.

8.3.2 Pick up the anchor latch and nipple assembly. Stab the anchor seal and latch into the seal bore above the packer and make up wrench tight (LH thread). Back off the anchor ¼ turn after make up as per manufacturer's instructions.

8.3.3 Run an additional joint of 5 1/2" 23 lbs/ft tubing and land off as low as possible in the slips.

Rig up wireline and pull the 3.688 AF plug body as a drift run.

The plug and prong will be re-run prior to setting the packer ( this enables circulation in case of well control problems ).

8.3.4 Run 5 1/2" tubing as required.

Note : the 5 1/2" 23 lbs/ft tubing will be run above the packer up to the TRSSSV.

8.3.5 Install 5 1/2" 23 lbs/ft x 5 1/2" 17 lbs/ft x-over ( assy x). Ensure proper make up torque is applied.

8.3.6 Install TRSSSV assembly without isolation sleeve installed, and one joint of 17 lbs/ft tubiing ( report TRSSSV number on the DOR ).

8.3.7 Connect control line to TRSSSV and pressure test to 7500 psi. Check visually to ensure the valve is fully open. Reduce the pressure to 3000 psi.

8.3.8 Continue running 5 1/2" 17 lbs/ft tubing. Install 2 off control line protectors per joint while running, one to be across coupling, and one mid-joint.

NOTE: Take care when putting in the slips that the control line is not crimped.

Record the total number of protectors run. These quantities should be recorded on the DOR, included on the final well status diagram and in the individual well file.

NOTE: 5 1/2" 17 lbs/ft 13Cr tubing will be run from the TRSSSV to the hanger.

8.3.9 Perform a 4" drift run through the TRSSSV.

8.3.10 Run the 5 1/2" 17 lbs/ft tubing to one joint below the hanger.

Prior to picking up the hanger, check the number of joints remaining on the deck is correct and agrees with the running list.

NOTE: The tubing hanger and running tool will have been prepared in the Well Services Workshop and sent offshore in the completion skip.

8.3.11 Prior to swallowing the slick joint note up and down weights.

8.3.12 Pick up one joint of 5 1/2" tubing, install circulating head. Carefully lower completion over slick joint whilst circulating at a low rate. Accurately establish and record the depth when the seal mandrel is bottoming out on the PBR.

8.3.13 The completion should be spaced out in such a way that the packer is not set across a coupling and that the seal mandrel is +/- 8 ft from the bottom of the PBR. Ref appx 6 for 9 5/8" casing tally.

The completion is set in neutral so space out should be such that when the hanger is landed off the packer is at packer setting depth.

8.4 Installing Tubing Hanger

8.4.1 The tubing hanger and running tool will have been prepared in the Well Services Workshop and sent offshore in the completion skip. Check dimensions of the tubing hanger. The Cameron CS1 WKI 2 stage manual TPD 4051 should be studied prior to running the hanger and a Cameron engineer should be on site for the space out and hang off operations. Ensure that Cameron container has been called out in time.

8.4.2 Remove the circulating head.

8.4.3 Install hanger and pup joint assembly (assy #x ) on the last joint as per the running tally, (ensure that the tie down bolts are fully retracted).

8.4.4 Bleed off the control line pressure. Cut and terminate the control line. Dress the control line through the hanger as per GUIDEX prcedures. Grease the hanger seal ring, OD and tie down shoulder. Connect a suitable length of control line to the top of the hanger outlet and open the TRSSSV.

8.4.5 Pick up and install the landing joint.

8.4.6 Lower the completion slowly and land off the tubing hanger. Monitor landing of the hanger through the spool side outlets. The groove machined in the lower hanger neck should line up with the outlet center. Mark the landing string at the rotary table.

8.4.7 Report on the DOR the final static string weight. Land off the string carefully.

8.4.8 With the hanger fully landed, make up the upper tie-down bolts, tighten sequentially using the ratchet wrench. Do not apply excessive force at this stage, aim more to initially squeeze the seal, with all tie-down screws taking equal load.

8.4.9 Hook up to the side outlet on the water injection spool and pressure test the 7.5/8" x 5" tubing annulus to 3,500psi for 15 minutes. This will test the G-22 seals and tubing hanger. Throughout the test, the tubing should remain open. In addition, ensure that the test port between the hanger seals is open (should fluid be seen to be leaking from this port, then it can be concluded that the hanger seals are leaking).

Bleed off the test pressure and drain the BOP / riser via the by-pass from the injection spool outlet. Establish the base annular flow (gallons / hour).

8.4.10 Install the pressure test equipment in one upper test port of the spool and a pressure releasing tool in the diametrically opposite test port. This is in preparation for testing the hanger body seals, but will be used initially to determine if pressure applied above the top seal, to assist seal energisation, is blowing past the seal. Ensure side outlet below hanger is open during the following tests.

Close the rams around the tubing landing string and pressurise above the hanger to 1500psi. With the check valve of the test port unseated, ensure that the applied pressure is not leaking past the seal. If leakage is seen, reduce the pressure until the leakage stops. With the pressure above maintained, again tighten the tie-down screws in sequence, this time using the torque wrench, in 50 ftlbs increments up to a value of 400 ftlbs.

Apply 3,000psi, maximum, above the hanger, and again tighten the tie-down screws, in sequence, (50 ftlbs increments) to a maximum of 600 ftlbs. Bleed off pressure above hanger.

With the test port check valve still unseated, apply test pressure through the opposite port, until air has been fully flushed from the system. Close the the port check valve and build up pressure, in stages, to 5,000psi.

If the required pressure in not achieved, release the test pressure and again pressure up above the hanger to 3,000psi. Re-tighten the tie-down screws to 700 ftlbs. Bleed off the pressure above the hanger and re-test the hanger seals.

Bleed off test pressure

8.4.11 Pressure test to 3500 psi between the seals of the tubing hanger by applying pressure at the test port. Observe for returns at the 'A' annulus outlet.

NOTE: Ensure the test fittings and check valves are removed from wellhead test ports. Chicksan loop open. Do not rely on stinger tools.

8.4.12 Rig up slickline complete with surface pressure control equipment and two auxiliary swab valves below a pump-in T piece on top of the landing joint. Run the 4.313" AFH plug and prong and set 4.313" AF nipple. Note the setting depth and check against tally. Pressure test the completion and both auxiliary swab valves seperately to 5000 psi. Close the TRSSSV, bleed off above and inflow test the TRSSSV. Equalise and open the SSSV. Pull the 4.313" AF plug and prong..

8.4.13 RIH and set the 3.688" AFH prong in the 3.688" AFH plug body ( below the new packer ).

8.5 Setting Packer

NOTE: Ensure that ther is no further movement of the completion with the prong installed. Movement of the completion upwards with the plug/prong installed may result in the packer setting due to forces exerted while lifting the fluid column above the plug.

8.5.1 Obtain base annular flow at the "A" annulus side outlet. Slowly increase pressure continuously to 4,000 psi ( 3,000 + diff.pressure ) to set the packer. Closely observe pressure build up, checking volumes pumped to ensure the prong is not leaking.

Fully energise the seal element with 4000 psi, maintain this pressure for 15 minutes. Note the volumes pumped and monitor the casing spool side outlets for returns.

If, required, repeat the above process to verify that the seals have energised.

8.5.2 Pick up to 20 klbs above string upweight to confirm anchor latch and packer slips are set.

8.5.3 Pressure test the complation to 5000 psi. This is the final tubing pressure test. Bleed down the pressure to 1000 psi ( pressure differential ) .

8.5.4 Test the "A" annulus via the side outlets (in leak off mode) to 1500 psi for 15 minutes stable ( ensure the annular bypass is open ).

8.5.5 Bleed off any tubing head pressure ( 1000 psi or pressure differential ) and inflow test the 3.688" AF plug and prong for 2 hours.

8.5.6 Install TWCV in the 7" tubing hanger and pressure test to 5000 psi. Bleed off the control line pressure to close TRSSSV.

8.5.7 Remove the BOP stack and riser having first ensured that the Xmas tree is ready for installation.

At this stage the well control lines of defence are:

  • Annulus
  • Packer pressure tested to 1500 psi from above.
  • Hanger seals pressure tested 3500 psi from above and 1500 psi from below.
  • Annulus filled with xxx brine.
  • Tubing
  • Deep set plug tested to 5000 psi and inflow tested for 2 hours.
  • TWCV installed and pressure tested 5000 psi from above

Additional

  • Closed and inflow tested TRSSSV.

8.6 Installing Tubing Bonnet

8.6.1 Install and Test WKM (Cooper) Tubing Bonnet.

8.6.2 Clean and inspect the BX-157 ring grooves in the unihead spool and the tubing hanger and clean and inspect the sealing surface. Check the condition of the GS seals on the tubing hanger extended neck.

Install a new BX-157 ring gasket in the unihead spool. Remove the adhesive tape securing the control lines and straighten part of the control lines, leaving at least one full turn wrapped around the recessed portion of the hanger neck.

8.6.3 Install a new 7" nominal DT seal in the tubing hanger neck. Lightly coat the seal sub with anti-scuffing paste and also apply the lubricant to the GS seals and the tubing hanger extended neck.

8.6.4 Pick up the tubing bonnet by means of the two lifting eyes provided and carefully lower it over the tubing hanger neck.

8.6.5 Make up the 13 5/8" 5000 psi flange nuts, taking care to tighten down the connection evenly. The final gap between the flange faces should be virtually zero (in any event less than 0.020").

Note: Ensure that the test port in the tubing bonnet is open when lowering over the DT seal sub to avoid pressure lock.

8.6.6 Pressure test the DT seal sub by applying pressure at the upper test port in the tubing bonnet. Test to 5000 psi for 15 minutes.

Pressure test the control line to 7500 psi.

8.6.7 Install the test equipment in the tubing bonnet lower test port and displace the air from the void by pumping fluid until it overflows from the control line exit port.

8.6.8 Install the specially modified Swagelok fittings in the 3/8" NPT control line tapping. Tighten down the ferrule nut to seal off the control line.

NOTE: Only fittings of the same material as the line should be used ( ie Monel 400 or Incoloy 825 ).

8.6.9 Ensure that the tubing bonnet upper test port is open. Apply a test pressure of 5000 psi for 15 minutes at the tubing bonnet lower test port.

8.6.10 On achieving a satisfactory test, remove the test equipment from the tubing bonnet lower test port and bleed all test pressure from the port, allow the test fluid to drain from the void space.

8.6.11 Cut off the control line approximately 1/2" above the ferrule nut of the Swagelok fitting. Clean the BX 151 ring groove and install the BX 151 ring gasket. Install a dual needle valve block on the control line exit, ensure that the flange is pulled down evenly by the four cap screws. It is recommended that the needle valve block be installed on the tubing bonnet such that the caps for the needle valve are pointing downwards. In this position the entry of dirt into the valve will be precluded and convenient access to operate the valve will be made.

8.6.12 To test the BX 151 flanged connection, install the test equipment in the 1/2" NPT port of the needle valve block. Ensure that the lower test port of the tubing bonnet is open and that both needle valves in the block are open. Apply 5000 psi test pressure and hold for 15 minutes.

8.6.13 On completion, remove the test equipment and ensure that bleed fittings are correctly installed in all the tubing bonnet and unitised head ports.

8.7 Installing Xmas Tree & Re-instatement

NOTE: Ref. Cameron Running Procedure Wellhead Manual TPD 4051.

8.7.1 Clean the BX-157 ring grooves and the sealing surfaces for the DT seal sub. Lightly coat the DT seal sub with anti-scuffing paste and install it in the wellhead.

8.7.2 Pick up the solid block Xmas tree and lower it over the DT seal sub down onto the tubing bonnet.

Note: Ensure that the orientation of the Xmas tree is correct for attachment of the flowline.

8.7.3 Make up the CIW clamp until the gap between the clamp hub faces is less than 0.020".

8.7.4 Install test equipment in the test port in the base of the Xmas tree and pressure test the connection to 5000 psi for 15 minutes.

8.7.5 On completion of the test, bleed all pressure from the test ports, remove the test equipment and ensure that all check valves are installed and sealed and that bleeder plugs are installed in all Xmas tree ports and tubing bonnet.

8.7.6 Hook up flow line.

8.7.7 Pressure test the Xmas tree body to 5000 psi against the TWCV in the tubing hanger. Monitor the volume pumped closely.

8.7.8 Pull the TWCV valve.

8.7.9 Rig up wireline and test wireline pressure equipment. Pull and retrieve deep set 3.688" AFH plug and prong from tailpipe.

8.7.10 Hand well over to Production Operations.

** end of full workover programme **

9. Appendices

Appendix 1 Well Datasheet

Appendix 2 Current Well Status

Appendix 3 Proposed Top Completion Schematic

Appendix 4 Proposed Full Workover Completion Schematic

Appendix 5 Existing Tubing tally

Appendix 6 9 5/8" Tally

Appendix 7 Sub Assembly Data sheets

Appendix 8 Risk Assessment

Appendix 9 Time-Activity Data Sheet

Appendix 10 Cost Analysis

Appendix 11 Tubing Handling and Examination Procedures