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 aninternal stinger. The type ‘H’ BPV is designed to hold pressure from thewellbore, or below, only. Cameron rates these BPV’s at 20,000 psi. Theyhave an internal, female, right hand running thread that mates with therunning, or retrieving tool, and an external, male, left-hand ACME settingthread that mates with the tubing hanger.Please refer to Figure 2E-15, below. The internal plunger consists of a valveand spring assembly that will seal and hold pressure from below. Whenoffset this plunger, see Figure 2E-16, allows pressure to by-pass andequalize above and below the BPV. This plunger also allows fluid to bepumped through the BPV in the event that it is necessary to pump kill fluidinto the well with the plug installed. The external seal is a lip type seal on theO.D. of the BPV. This seal is energized when the plug is rotated into themating profile in the tubing hanger. The type ‘H’ BPV should not be overtightened.Over-tightening this type of plug will not help it seal, but can makeit hard to remove.Figure4.4 Running Procedures for Type ‘H’ PlugsBefore 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 (Figure2E-19)A) Measure from the lock-screws on the top flange of the tubingspool to the top of the tree connection (if installing through atree), or to the drill floor (if installing through BOPE). To thisdimension add 18 to 36 inches. This is the length of polishedrod required.B) Assemble the polish rod and attach the Retrieving/Running toolto the bottom piece.C) Thread the plug onto the Retrieving/Running tool (8 to 8-1/2rounds) and tighten with two 18” pipe wrenches. The connectionshould be tight enough that when threading the plug into thehanger it will not break out before it is seated.D) Coat the plug threads and lip seal with an even application ofnever-seize.

SAUDI ARAMCO WORKOVER MANUALDrilling & Workover Engineering Department May 1999CHAPTER 2 WORKOVER PRACTICESSECTION E WELLHEADS___________________________________________________________________________________________________________________________

29 of 33E) Lower the assembly through the tree, or BOP, and stab plug intothe 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 hasseated.H) With an 18” pipe wrench, continue to rotate the rod to the left until

they become easy to turn. This indicates that theRunning/Retrieving tool is now backing out of the plugI) Continue to turn 8 to 10 rounds to completely disengage theRunning/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 tubingspool to the top of the tree connection (if installing through atree), or to the drill floor (if installing through BOPE). To thisdimension add 18 to 36 inches. This is the length of polishedrod required.B) Assemble the polish rod and attach the Running tool to thebottom piece.C) Thread the plug onto the Running tool and make it up until itbottoms out, no torque is required.D) Coat the plug threads and lip seal with an even application ofnever-seize.E) Lower the assembly through the tree, or BOP, and stab plug intothe hanger.F) Turn to the right one turn to align the threads. Watch for the rodto drop about ½ inch; this indicates that the torque pin hasengaged 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 hasseated.H) With an 18” pipe wrench, continue to rotate the rods to the leftuntil a maximum of 50 ft lbs. has been applied. Under nocircumstances should the plug be over-tightened.I) Pick up the rod about ½ inch and continue to turn to the left tothread the running tool out of the plug.J) Continue to turn 8 to 10 rounds to completely disengage theRunning tool.K) Remove the rod assembly from the tree, or BOP.


30 of 335.0 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 anduncemented 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 ProducersRequired 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 checklanding base for corrosion and proper support. Mark/report wellheadand valve operators orientation. Flare gas off tubing and TCA, if any. PTTCA to 1000 psi. Kill well by bullheading kill weight NaCl brine down thetubing.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. RDSAWL. Circulate tubing and TCA with kill weight brine. Set BPV intubing 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 arestuck, cut tubing above packer. POH and LD tubing. Inspect and reportcondition 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 TubingSpool.


31 of 33Re-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 landingbase and corroded section of 13? " casing. Clean 9? " casing fromcement and inspect for corrosion.C) Re-stub cut-off casing(s) and fill the annulus with Class G neat cementslurry.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 withmechanical 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? " CasingSpool with new bushing. PO and PT 9-5/8” bushing to 1000 psi.B) NU new/reconditioned 13? " × 11" × 2" × 2", 3M Tubing Spool. NUBOPE .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. RIHwith 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 equipmentinstalled.I) Report the length of casing stub(s), sizes and types of flanges andspools.

SAUDI ARAMCO WORKOVER MANUAL

Drilling & Workover Engineering Department May 1999CHAPTER 2 WORKOVER PRACTICESSECTION E WELLHEADS___________________________________________________________________________________________________________________________

32 of 335.2 Typical Re-Stubbing Procedure for PWI WellsRequired Isolation Barriers: (2) Mechanical(1) Non-MechanicalNote: 2nd 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 checklanding base for corrosion and proper support. Mark/report wellheadand valve operators orientation. Flow well to pit and check for oil andgas. Close 10” Ball Valve and ensure valve is holding well pressure. ReopenBall ValveB) 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. NUBOPE on top of Ball Valve , pumping brine down the wellbore whilenippling up. PT to 300/3000 psi.C) RIH with 7", 23# casing scraper to + 6500’ and POH. RIH with 7” EZSVBP. Set EZSV at + 6400’ and PT to 3000 psi. If PT fails, establishinjection 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” BallValve.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 landingbase and corroded part of 13? " casing. Clean 9? " casing from cementand inspect for corrosion.C) Re-stub cut-off casing(s) and fill the annulus with Class G ‘Neat’ cementslurry.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 withmechanical slips inside landing base.


33 of 33Re-completion procedure can vary with specific well requirements.A) Dress 9-5/8” casing stub. NU new/reconditioned 13? " x 13? " CasingSpool 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. RIHwith 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. Runsinker bar and report fill.I) Report the serial number all new/reconditioned wellhead equipmentinstalled.J) Report the length of casing stub(s), sizes and types of flanges andspools.

SAUDI ARAMCO WORKOVER MANUALDrilling & Workover Engineering Department May 1999CHAPTER 2 WORKOVER PRACTICESSECTION F LOST CIRCULATION__________________________________________________________________________________________________________________________

LOST CIRCULATION1.0 INTRODUCTION2.0 CONVENTIONAL LOSS CIRCULATION MATERIAL2.1 Characteristics2.2 Procedures3.0 ACID SOLUBLE GROUND MARBLE3.1 Characteristics3.1.1 Selection of CaCO3 Particle Size Basis3.1.2 Typical CaCO3 Pill Formulation3.1.3 Average Properties of CaCO3 Carrier Fluid3.2 Recommended Procedures4.0 GUNK PLUG4.1 Characteristics4.2 Procedures5.0 POLYMER PLUG5.1 Types of Polymer Plugs5.2 Flo-Chek5.3 Temblok-1005.4 High Temperature Blocking Gel5.5 Protectozone6.0 BARITE PLUG6.1 Characteristics6.2 Slurry Volume Calculations6.3 Pilot Testing6.4 Pumping, Displacement Rates and Equipment6.5 Procedures7.0 THIXOTROPIC CEMENT7.1 Characteristics7.2 Procedures8.0 CEMENT PLUG8.1 Characteristics and Precautions8.2 Procedures9.0 FOAM CEMENT9.1 Characteristics9.2 Procedures


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LOST CIRCULATION1.0 INTRODUCTION1.1 Loss of circulation occurs when the formation drilled is extremely permeableand a pressure differential is applied toward the formation. The mud loss ratedramatically increases by the excessive overbalance pressures created bythe hydrostatic head of the column of mud in the hole. In some cases,decreasing the differential pressure by reducing the fluid density and pumpingrate or pressure will stop fluid losses and regain circulation. However, themost effective method for combating lost circulation is to reduce thepermeability of the borehole wall by introducing properly sized bridgingmaterial, commonly known as loss circulation material (LCM) into the rockpores with a high viscosity pills. Bridging particles contained in the mud willnot seal the zone if they are smaller than the formation pores.Potential loss of circulation zones usually encountered in Saudi Aramco’sfields includePre-Neogene Unconformity (PNU)Umm Er Redhuma (UER) Major lossesWasia FormationShuaiba Major lossesArab-D Reservoir Major lossesHanifa ReservoirLower Fadhili ResrevoirHaurania Zone Major lossesBelow the base of the Jilh dolomite1.2 Loss circulation material (LCM) is normally added to the circulating drillingmud, or in a high viscosity pill to be spotted across the lost circulation zone.The LCM includes, but is not limited toA) Conventional bridging agents;Fibrous Material ........................................... Cedar FiberFlake Material .............................................. Mica coarse and fineCellophaneGranular Material ......................................... Walnut shellsCotton seed hulls


the threaded style back

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