PR-1047 Well Integrity Maintenance

PR-1047, Well Integrity Maintenance Procedure

Petroleum Development Oman LLCRevision: 2.0

Effective: May2007

Revision: 2.0Effective: May 2007Petroleum Development Oman LLC

Petroleum Development Oman L.L.C.

RESTRICTEDDocument ID: PR-1047May 2007Filing Key: Business ControlWell Engineering

Well Integrity Maintenance ProcedureUser Note:

The requirements of this document are mandatory. Non-compliance shall only be authorised by the Document Authority or his Delegate through STEP-OUT approval.

A controlled copy of the current version of this document is on PDO's EDMS. Before making reference to this document, it is the user's responsibility to ensure that any hard copy, or electronic copy, is current. For assistance, contact the Document Custodian" Document Custodian or the Document Controller.Users are encouraged to participate in the ongoing improvement of this document by providing constructive feedback.

Please familiarise yourself with the

Document Security Classification DefinitionsThey also apply to this Document!Keywords:WIT, Wellhead Integrity Test, SIT, Subsurface Integrity Test, Well Failure Model, Well type, gas lift wells, steam injection wells, free flowing wellsThis document is the property of Petroleum Development Oman, LLC. Neither the whole nor any part of this document may be disclosed to others or reproduced, stored in a retrieval system, or transmitted in any form by any means (electronic, mechanical, reprographic recording or otherwise) without prior written consent of the owner.

This document can be accessed via the following link: http://sww3.pdo.shell.om/getdoc?dataid=95049 (PDO Intranet)

This page was intentionally left blank

i Document Authorisation

Authorised For Issue: May 2007

ii Revision History

The following is a brief summary of the 4 most recent revisions to this document. Details of all revisions prior to these are held on file by the issuing department.Note that changes made as part of Document Maintenance (correction of broken hyperlinks) will not be recorded in this Revision Table.Revision No.DateAuthor/ EditorChanges/ Remarks

2April 2007 Obaid Al Farsi (UWXZ/4)

Christian Koepchen (UWH/2),

Robin Gardiner (UPT/2)Alignment of Well Integrity Maintenance Procedures with the Well Failure Model

101/01/2002TWM/92

UOW 1Initial Issue, post merger of Well Services & Well Engineering.1

014/10/1998TM Services OTW/1Initial Issue

iii Related Business ProcessesCodeBusiness Process (EPBM V.4.0)

EP.63Design, Drill, Modify, Service and Abandon Well

iv Related Corporate Management Frame Work (CMF) DocumentsThe related CMF Documents can be retrieved from the CMF Business Control Portal. Other, non-CMF documents and links to information relevant to Well Engineering can be found on the Well Engineering Documentation Page.TABLE OF CONTENTS

3iDocument Authorisation

4iiRevision History

4iiiRelated Business Processes

4ivRelated Corporate Management Frame Work (CMF) Documents

71Introduction

71.1Background

81.2Purpose

81.3Scope

81.4Distribution/Target Audience

81.5Review and Improvement

81.6Step-out and Approval

92Procedure Description

102.1Wellhead Integrity Test (WIT)

102.1.1Suspended Wells

122.1.2Well Type 1 (High Pressure Wells or high GLR or H2S Wells)

202.1.3Well Type 2 (Free Flowing Low Pressure Oil Wells, < 20,000 kPa)

272.1.4Well Type 3 (Gas lift Wells)

332.1.5Well Type 4 (Steam Injection Wells)

402.1.6Well Type 5 (Sub-hydrostatic, pumped wells)

462.1.7Well Types 6 and 7 (Water Injection/ Disposal wells with/ without tubing)

522.2Subsurface Integrity Test (SIT)




852.2.4Well Type 4 (Steam Injection with Packer)



1132.3Subsurface Integrity Test (SIT), Maintenance




1162.3.4Well Type 4 (Steam Injection with Packer)



1192.4Preventive Well Maintenance of Wellhead related Surface Equipment

1192.4.1Preventive Maintenance of OTIS Control Panels

1192.4.2Preventive Maintenance of Beam Pumps

1222.5Corrective Well Maintenance

1222.5.1General Checks

1232.5.2Christmas Tree Change-Out

1272.5.3Corrective Maintenance of Christmas Tree Valves and Components

1272.6Procedure for acid soaking to clean Tubing hanger BPV thread profile

1272.6.1Safety Precautions while attempting acid soak.

1272.6.2Procedure for filling acid in Christmas tree

1273Identified Hazards and Threats

1274Roles and Responsibilities as referred to in this document

1275Appendices

1275.1Appendix 1, Forms and Reports

1275.2Appendix 2, Glossary of Terms, Abbreviations and Definitions

1275.3Appendix 3, Related Business Control Documents and References

1275.4Wellhead Maintenance Guides

1275.4.1Cameron

1275.4.2FMC

1275.4.3Ingram Cactus

1275.4.4McEvoy Model C Style Y Blocks

TABLE OF FIGURES(Double-click to view in presentation mode)127Figure 21, Stem Packing with Check Valve

127Figure 22, Low Pressure Grease Fitting

127Figure 23, Explosion Drawing of Valve

127Figure 51, Valve Drawing Sealant and Body Filler Connections

LIST OF TABLES7Table 11, Well Types and Colour Coding

13Table 21, SCSSSV Control line pressure Limits in kPa

21Table 22, SCSSSV Control line pressure Limits in kPa

53Table 23, Test Pressures for Annuli Tests

127Table 24, FLS Gate Valve, Description of Parts

127Table 41, Roles and Responsibilities

127Table 51, Glossary of Terms, Abbreviations and Definitions

127Table 52, Related Business Control Documents and References

LIST OF EQUATIONSN/A1 Introduction1.1 Background

In April 2004 PDO introduced SP-2017, Well Failure Model as the Standard in which PDOs Well Integrity related requirements are defined, this in line with CP-118, Well Life Cycle Integrity Code of Practice (WLICoP).Since then both these documents have been under continuous development incorporating ideas and challenges brought forward by the members of the Well Integrity Working Group resulting in new versions of these documents.It should be noted that all legacy Well Maintenance related documents, notably PR-1037, PR-1472, PR-1474, PR-1477, PR-1484 shall be deemed withdrawn with the official endorsement of this Procedure.

The Well Failure Model distinguishes the following categories of well integrity related activities and specifies these for 7 well types in terms of frequency and scope. Well Integrity Testing (Preventive / Planned Maintenance) Wellhead Integrity Test (WIT) (See Chapter 2.1 below)

Note:The WIT comprises the flow-wetted parts of the completion

Subsurface Integrity Test (SIT) (See Chapter 2.2 below)

Note:The WIT comprises all the flow-wetted parts of the completion.WIT and SIT are intended to be interventionless. However it has been recognized that, in order to acquire true knowledge of whether or not a valve can be considered a barrier as per the definition given in SP-1217, Well Control Barriers, there may be a need to set plugs in the completion or the wellhead and pressure test against these to establish their integrity. Such a test would be called a Pressure Integrity Test, PIT. It is PDOs aim to move to interventionless integrity testing using novel technologies.

Subsurface Integrity Test (SIT), Maintenance (Chapter 2.3)The seven Well Types are:

Table 11, Well Types and Colour Coding

Well TypesColor Coding in this document

Well Type 1

High Pressure Well - >20,000 kPa (Actual CITHP) or high GLR (>300:1 gas to liquid ratio) or high H2S (>500ppm)

Well Type 2Free Flowing low pressure Oil Well - < 20,000 kPa

Well Type 3Gaslift Well

Well Type 4Steam Injection well

Well Type 5Sub-hydrostatic pumped well, minimum one casing string with or without packer

Well Types 6 and 7

1) Water Injection / Disposal Well (with tubing)2) Water Disposal Well (no tubing)

Suspended Wells (not listed as separate Well Type in the Well Failure Model)

This Procedure further covers:

1) Preventive Well Maintenance of Wellhead related Surface Equipment (Chapter 2.4)2) Corrective Well Maintenance (Chapter 2.5)3) Procedure for acid soaking to clean Tubing hanger BPV thread profile (Chapter 2.6)1.2 Purpose

This Procedure sets out the standards which all Well Maintenance related operations have to conform to.

It forms the framework from which detailed work practice procedures can be developed and maintained by PDO and contractor companies who perform operations on behalf of PDO.

1.3 ScopeThis Procedure is applicable to all Well Integrity related operations conducted either by PDO or Contractor personnel on all PDO well equipment.1.4 Distribution/Target Audience

This document will be distributed to all PDO Section Heads who have interfaces with the Well Services Operations, all Well Services Supervisors and Contractor Supervisors.

1.5 Review and Improvement

Any user of this document who wishes to provide constructive feedback, or who encounters a mistake or confusing entry is requested to immediately notify the Document Custodian.

This document shall be reviewed as necessary by theDocument Custodian, but no less frequently than every four years. Triggers for full or partial review of this Procedure are listed in PR-1444, Well Engineering Management Framework in Chapter 5.2.4, Document Review.

1.6 Step-out and Approval

Step-Outs shall be managed as described in PR-1444, Well Engineering Management Framework in Chapter 5.2.1, Variance from a Standard (Step-Out)The Step-Out Request Form can be downloaded from here.

2 Procedure Description

Whenever a SIT is carried out it shall be combined with a WIT.

Where pressure exists for testing, a differential pressure shall be applied across the valve being tested by blowing down the flow line or downstream fixed volume to the minimum pressure practical. Where it is not possible to blow down the flow line fully, the minimum pressure differential (P) at the start of test shall be 1.2 times the Allowable Leak Rate by valve size as stated above.

Note :The reasoning behind this rule is that the purpose of leak testing valves is to assess their likely performance in the worst case scenario; for a Christmas Tree valve this is isolation of the well in case of a flow line rupture. In a failure situation, a greater pressure differential would exist across the valve than under test conditions; so a pass under test conditions demonstrates integrity. A fail under these conditions will also have occurred before the valve has equalised; therefore this method is deemed to be a valid test method.Where no well pressure exists in lieu of testing, the valve shall be cycled and maintained in accordance with manufacturers instructions; this shall be deemed a test Pass.Note:Whenever a SIT is carried out in conjunction with a WIT, the valves will be tested using applied pressure above LMV, if fitted, or UMV. The decision not to set a Two-Way Check Valve below the tree (which would give information on the integrity of the lowest Master Valve) is based on a Risk/ Cost/ Value judgement; the value of knowing the result of the Master Valves status is outweighed by the effort/ cost of achieving a valid test. In risk term this judgement leads to a rating of C2 on the PDO Risk Matrix.

In situations where CITHP is > 0 but corresponding to < 1.2 x Allowable Leak Rate, pressure equalisation across the valve within the test period will be deemed a test Fail as it demonstrates condition degradation.

The Pressure Measurement Method can be either by Pressure Build-up within an enclosed volume or by Bleed-off from an enclosed volume.

Note:When a valve test is carried out it is vital to maintain a small positive pressure in the cavity to be tested, this to ensure

a. that there is no zero error on the gauge

b. that the cavity to be tested is already filled with fluid2.1 Wellhead Integrity Test (WIT)2.1.1 Suspended Wells

When a well of any type has been suspended, the following test shall be carried out to confirm suspension and valve(s) integrity. Where a tree is still fitted, the standard tree test shall be carried prior to the Suspension Plug test below.2.1.1.1 WIT Task Function/ Leak-off test Suspension Valve(s)

aLL Well TypeS

Task CodeSUVIW/ SUVOW

Task Decription Leak-off test Suspension Valve(s)

1) Ensure the Suspension Valve is closed.

2) Bleed off downstream pressure.

3) Install the Test Manifold and a secured flexible bleed line from the appropriate Valve to a portable waste container in accordance with .

4) Close in the bleed point.

5) Open the Suspension Valve to check for pressure.

a. Where no pressure exists for testing, maintain the valve(s) as per the Maintenance Guide for the appropriate valve type / manufacturer.

b. Where pressure exists for testing, close the Outer or only Suspension Valve.

6) Bleed Suspension Valve downstream pressure.

7) Record the test Start pressure in the WIMS Checklist.

8) Measure the pressure build-up above the Suspension Valve over 10 minutes using a gauge known to be accurate.

9) Record the test Finish pressure in the WIMS Checklist.

10) If the test result is within the Allowable Leak Rate for the tested valves size then record the result as Pass with Start and Finish pressures in the WIMS WIT Checklist; record the number 1 in the Number of Tests done field.

11) If the test results in a Fail on the first attempt, grease and cycle the valve and re-test it until a Pass test result is achieved or no improvement in results is seen.

a. Flush the Valve Cavity after two failed tests using flushing liquid.

12) Record the final test (last test carried out) result in the WIMS WIT Checklist including Start and Finish pressure and number of tests done.

Note:Carry out Steps 6 to 12 for the second valve where two valves are fitted!

2.1.1.2 WIT Task Leak-off Test Down-Hole Plug

aLL Well TypeS

Task CodeSUPW

Task Decription Leak-off test Down-Hole Plug

1) Open the Suspension Valve(s).

2) Bleed off the pressure above the plug in stages to a portable waste drum; monitor returns.

Note:Where returns are gas, bleed off to atmosphere if safe to do so (e.g. no H2S)

3) Where pressure cannot be bled down or where the returns are in excess of available storage capacity, abort the test and record test as Fail.

Note:Record the type of returned fluid in the free text field in the WIMS WIT Checklist to aid the investigation.



6) Measure the pressure build-up in the tubing and the Tree Cavity over 4 hours as described in the note below. Use the Well Failure Model Leak Rate Equation to determine if the leak rate is acceptable.

Note:Where a well is plugged or suspended, first carry out the Tree Valve Leak-off test using any pressure that has built up above the plug. Then bleed off the pressure above the plug, close in the bleed and carry out and extended (4 hour) inflow test on the plug recording the results at hour average over the test period (i.e. one eighth of the observed rise over the 4 hour test period). Simply cycle and maintain the tree valves where no pressure is initially seen above the plug.


Note:WIMS Master Data for the well will be adapted to include allowable leak rates for any plugs fitted. So check WIMS to confirm the calculated allowable leak rate!

2.1.2 Well Type 1 (High Pressure Wells or high GLR or H2S Wells)

The Testing Frequency is as per SP-2017, Well Failure Model2.1.2.1 Safety Precautions2.1.2.1.1 Permit to Work

Ensure that PR-1172, Permit to Work Procedure is followed.

2.1.2.1.2 H2SWell Type 1, High Risk Wells, comprises H2S wells. This Chapter highlights the particularities relating to H2S wells and provides links to Reference Documents. 1) Comply with all items outlined in SP-1219, Drilling Specification Hydrogen Sulphide.

2) A calibrated pressure gauge fitted to the tree cap with bleed facility (in line with H2S controls) maybe bled off to outside fence downwind of the work area.

2.1.2.2 General Preparation

1) Fit a calibrated pressure gauge with bleed facility to the tree cap. Pressure can be bled off to a portable waste drum.2) Establish the Valve Manufacturer, type and size and check same against data recorded in DIMS. For Solid Block Trees also record Part Number and check same against data recorded in DIMS.

3) Pick the correct Wellhead Maintenance Guide from the following:

a. Cameron (see Chapter 5.4.1b. FMC (see Chapter 5.4.2)

c. Ingram Cactus (see Chapter 5.4.3)

d. McEvoy (see Chapter 5.4.4)

2.1.2.3 Notes of Guidance

1. The allowable Leak Rates for Valves are listed by valve size in the Allowable leak rates tab of SP-2017, Well Failure Model.

2. Valve leak test durations are 10 minutes; SCSSSV test leak test durations are 30 minutes.

3. Where a valve to be tested is NOT fitted, omit the respective task.

4. The test pressure can be replenished from the reservoir (by opening the Master Valves) or using an external pump unit. Both methods have advantages and disadvantages as listed below:

a. Pumpingkeeps UMV test barrier intact but introduces HSE risks associated with mechanical tie in to sour HP wellb. Cycling UMVavoids mechanical tie-in risk but breaks UMV tested barrier.Note:Either method can be used provided risks are considered.

5. The tests and the work to be carried out are defined, for each individual well type, in the Well Failure Model, in the worksheet titled Well Integrity Testing/ Maintenance Matrix (ensure work is carried out based on the approved version of the Well Failure Model).

6. Tests must be carried out in the order stated below as the valve status is assumed as left from the previous test

7. Valves must not be greased before testing. Valve maintenance will be carried out after the initial test, not before (irrespective of whether the test results is a pass or fail), this to allow the condition as found to be analysed in terms of failure rates for both as found and as left conditions.

Table 21, SCSSSV Control line pressure Limits in kPaMinimum Pressure to activate flapper to open

3.5, 13.7lbs/ft Completion StringMinimum pressure to activate the flapper to open = expected CITHP + 12,500kPa (Flapper Opening Pressure) + 3,500kPa (Safety Factor for Equalization)

3.5, 10.2lb/ft Completion StringMinimum pressure to activate the flapper to open = expected CITHP + 16,900kPa (Flapper Opening Pressure) + 3,500kPa (Safety Factor for Equalization)

4.5, 16.9lb/ft Completion String Minimum pressure to activate the flapper to open = expected CITHP + 15,200kPa (Flapper Opening Pressure) + 3,500kPa (Safety Factor for Equalization)

The maximum pressure for the control line used in PDO under SAP # 1000004564 is 182,000kPa.

2.1.2.4 Testing2.1.2.4.1 WIT Task Carry out External Leak TestWell Type 1 wit

Task CodeELCW /CAPW

Task DeScriptionCarry out external leak check

1) Check all gaskets, flanged, bolted connections and packings for leakage and rectify as required.

2) Measure and record all annulus pressures and the closed in tubing pressure (CITHP).

Note:Pressure within bolted or flanged connections must be bled off prior to attempting to pull up any minor weeps

2.1.2.4.2 WIT Task Flush Instrument Impulse Lines.

Well Type 1 wit

Task CodeILFW/ PRT/ PRA/ PRB/ PRC

Task DeScription Flush instrument Impulse Lines & Check Pressure Reading Equipment (Local and remote)

1) Shut in production at the choke, close the HIPPS valve (if fitted), shut in FWV, UMV and LMV to isolate the wellhead from the reservoir and the flow line pressure. Use a hand pump and control line fluid to ensure that all pressure reading lines, i.e. those in contact with well fluid, are free from obstruction.

2) Where transmitters are fitted, ensure that actual local pressure gauge readings agree with remote readings. Where differences occur, rectify or note the problem in the free text area of the WIT Checklist.

3) Install a secured flexiline to allow safe pressure bleed-off of sour fluids from the wellhead to a downwind location outside the well site fence area.

4) Check pressure rating, condition and specification of needle valves and replace as required.

Note:Replace all non-standard needle valves with double block and bleed valves.

Attention!

Industry pressure release incidents have been caused by impulse lines being blocked, leading to actual pressures in annuli not being shown on the gauges. The blockages can be due to either ingress of well fluids or build-up of valve grease. It is therefore vital to ensure impulse lines are clear before attempting any tests or maintenance activities.

2.1.2.4.3 WIT Task Function/ leak-off test Flow Wing Valve (Inner or only)Well Type 1 wit

Task CodeFWVIW/ FWVOW

Task DeScription Function / leak-off test Flow Wing Valve (Inner or only)

Note:This method assumes that a combination of LMV and UMV provides a leak-tight seal.

1) Shut in production at the choke and close HIPPS valve (to be done remotely by Production Operations).

2) Zero check the methanol line or flow line pressure gauge, ensuring the line to the gauge is open.

3) Zero check the Swab Valve Pressure Gauge, ensuring that the Swab Valve and the line to Gauge are open.

4) Close LMV and UMV.

5) Open FWV.

6) Bleed off pressure between HIPPS, where fitted, or Location and wellhead through KWV.

7) Close KWV and FWV.

8) Replenish Tree Cavity pressure by either pumping or cycling LMV and UMV.

9) Record Test Start pressure at the swab pressure gauge in the WIMS Checklist.

10) Measure the pressure drop in the enclosed tree cavity over 10 minutes using a gauge known to be accurate.

a. Monitor the pressure rise in the enclosed flow line section between the HIPPS and the FWV, using the methanol line or flow line Pressure Gauge.

Note:If the pressure rise observed on the monitoring gauge exceeds the pressure rise corresponding to the Allowable Leak Rate, specified in the Well Failure Model (Allowable leak rate sheet), the FWV is recorded as a Fail; such a result also suggests that the combination of UMV/ LMV is also a Fail. In this instance, grease all valves and re-test FWV. If the result is the same then the Well Services Supervisor or the Asset Well Integrity Engineer must be informed before taking any further action.11) Record Test Finish pressure in the WIMS Checklist.

12) If the test result is within the allowable leak rate for the tested valves size, record the test as a Pass with Start and Finish pressures in the WIMS WIT Checklist; record the number 1 in the Number of Tests done field.


a. Flush the valve Cavity after two failed tests using flushing liquid.


2.1.2.4.4 WIT Task Function/ leak off test Swab ValveWell Type 1 wit

Task CodeSVW

Task DeScription Function/ Leak-off test Swab Valve

1) Close SV.

2) Open UMV and LMV.

3) Bleed SV downstream cavity.



6) Measure the pressure build-up above the SV over 10 minutes using using a gauge known to be accurate.






2.1.2.4.5 WIT Task Function/ Leak-off test Kill Wing Valve Inner (or only)Well Type 1 wit

Task CodeKWVIW

Task DeScription Function / Leak-off test Kill Wing Valve Inner (or only)

1) Close KWVI if not already closed.

2) Bleed down KWVI downstream cavity and install a pressure gauge and double block and bleed system.

3) Re-pressurize the tree body if required by the chosen method and allow the pressure in the tree body to stabilize.


5) Record test Start pressure in the WIMS Checklist.

6) Measure the pressure build-up downstream of the KWVI over 10 minutes using the installed pressure gauge.






Note:Repeat this Procedure for the KWVO, if fitted.

2.1.2.4.6 WIT Task Function/ Leak-off test the Upper Master Valve UMV

Well Type 1 wit

Task CodeUMVW

Task Decription Function/ Leak-off test Upper Master Valve

1) Close UMV

2) Open SV or KWV (dependent on where the measurement will be taken)

3) Open the bleed facility to bleed down the Tree Cavity to as near zero as possible maintain some positive pressure on the gauge.



6) Measure the pressure build-up in the Tree Cavity over 10 minutes.






2.1.2.4.7 WIT Task Function/ Leak-off test the Lower Master Valve LMV

Well Type 1 wit

Task CodeLMVW

Task Decription Function/ Leak-off test Lower Master Valve

1) Close LMV.

2) Open UMV.

3) Open the bleed facility to bleed down the Tree Cavity to as near zero as possible; maintain some positive pressure on the gauge.



6) Measure the pressure build-up over 10 minutes.






2.1.2.4.8 WIT Task Function/ Leak-off test the Down-Hole Safety Valve

Well Type 1 wit

Task CodeSSSVW/ APRW/ CLA

Task Decription Function/ Leak-off test Down-Hole Safety Valve e.g. SCSSSV/ ICV/ Storm Choke or Plug

1) Open the LMV, record the CITHP.

2) Close the SCSSSV by trip function locally.

3) Open the FWV.

4) Using the choke, bleed off the pressure above the closed SCSSSV in stages to flow line pressure.

5) Close FWV.

6) Bleed off the remaining pressure through the flexiline, hooked up to the KWV.


8) Record the A annulus pressures at the start of the test.


10) Measure the pressure build-up in the tubing and the Tree Cavity over 30 minutes using a gauge known to be accurate; use the Well Failure Model Leak Rate Equation to determine if the leak rate is acceptable.


12) Record the A Annulus pressure at the end of the test.

13) Whilst conducting the above build-up survey, confirm (e.g. by looking, listening and feeling) that there is no communication with the reservoir through the Control Line.

14) If the first test fails, cycle the valve and re-test it until the test results in a Pass or no improvement in results is seen. Ensure that the pressure across the SCSSSV is equalized before cycling. A pump may be required to obtain pressure above the SCSSSV.

15) Record the final test (last test carried out) result in the WIMS WIT Checklist including the Start and the Finish pressure and the Number of Tests done.

16) Bleed off any built-up pressure through the chosen bleed point.

17) Maintain (e.g. grease or lubricate) all Tree Valves.

18) Re-open the SCSSSV.

19) Adjust the Control Line pressure to within the limits stated and record the pressure in the WIT Checklist. Recommend control line pressures, but do not adjust at the Wellhead Panel.

Notes:1.)WIMS Master Data for the well will be adapted to include allowable leak rates for SSSVs. So check WIMS to confirm the calculated allowable leak rate!

2.) Where a well is plugged or suspended, first carry out the Tree Valve Leak-off test using any pressure that has built up above the plug. Then bleed off the pressure above the plug, close in the bleed and carry out and extended (4 hour) inflow test on the plug recording the results at hour average over the test period (i.e. one eighth of the observed rise over the 4 hour test period). Simply cycle and maintain the tree valves where no pressure is initially seen above the plug.

3.) For SCSSSVs with no equalizing feature it will be necessary to equalise the pressure across the valve with inhibited water by means of a high pressure pump hooked up to the kill wing valve.

2.1.2.4.9 WIT Task Visual Inspection of condition/ deflection / clashes / instrumentation or fitting weeps

Well Type 1 wit

Task CodeVIW

Task Decription Visual Inspection of the condition/ deflection / clashes instrumentation or fitting weeps

1) Visually inspect all tree components and report any anomalies or unacceptable degradation through free text format area of the WIT Checklist suggesting possible remedies required.

2) Visually inspect wind socks and other related well site safety equipment; report anomalies and replace equipment as required.

Note:As this section is open to interpretation and has no clear pass or fail criteria it is important to describe the problem noted clearly to allow the Well Integrity Engineer to make the decision whether to request follow-up repair or not.

2.1.2.4.10 WIT Task Function/ Maintain remaining Annulus Valves

Well Type 1 wit

Task CodeMAVW/ MTVW

Task Decription Function / Maintain all Tree Valves and remaining Annulus Valves

1) Lubricate or grease all tree and annulus valves as per Maintenance Guide for the appropriate valve type / manufacturer.

2) Return all valves to operational position.

Note:To ensure the valves ongoing operability, it is vital that all valves (especially tree valves) are maintained in line with Manufacturers Instructions irrespective of test result.

2.1.3 Well Type 2 (Free Flowing Low Pressure Oil Wells, < 20,000 kPa)

The Testing Frequency is as per SP-2017, Well Failure Model2.1.3.1 Safety Precautions2.1.3.1.1 Permit to Work



1) Fit a calibrated pressure gauge with bleed facility to the tree cap. Pressure can be bled off to a portable waste drum.

2) Establish the Valve Manufacturer, type and size and check same against data recorded in DIMS. For Solid Block Trees also record Part Number and check same against data recorded in DIMS.







2. Valve leak test durations are 10 minutes; SCSSSV test leak test durations are 30 minutes.







Table 22, SCSSSV Control line pressure Limits in kPa

Minimum Pressure to activate flapper to open

3.5, 13.7lbs/ft Completion StringMinimum pressure to activate the flapper to open = expected CITHP + 12,500kPa (Flapper Opening Pressure) + 3,500kPa (Safety Factor for Equalization)

3.5, 10.2lb/ft Completion StringMinimum pressure to activate the flapper to open = expected CITHP + 16,900kPa (Flapper Opening Pressure) + 3,500kPa (Safety Factor for Equalization)

4.5, 16.9lb/ft Completion String Minimum pressure to activate the flapper to open = expected CITHP + 15,200kPa (Flapper Opening Pressure) + 3,500kPa (Safety Factor for Equalization)

The maximum pressure for the control line used in PDO under SAP # 1000004564 is 182,000kPa.


Task CodeELCW /CAPW






Well Type 2 wit

Task CodeVIW



2) Visually inspect well site safety equipment; report anomalies and replace equipment as required.



Well Type 2 wit



1) Shut in production at the choke, close the HIPPS valve (if fitted), shut in FWV, UMV and LMV to isolate the wellhead from the reservoir and the flow line pressure. Use a hand pump and control line fluid to ensure that all pressure reading lines, i.e. those in contact with well fluid, are free from obstruction.


3) Install a secured flexiline to allow safe pressure bleed-off of fluids from the wellhead to a portable waste drum.



Attention!



Task CodeFWVIW/ FWVOW

Task DeScription Function / leak-off test Flow Wing Valve (Inner or only)

Note:This method assumes that a combination of LMV and UMV provides a leak-tight seal.

1) Shut in production at the choke (if fitted), close the ESD Valve or the FWV and close the Location Valve.

2) Zero check the flow line pressure gauge (if fitted), ensuring the line to the gauge is open.

3) Zero check the Swab Valve Pressure Gauge, ensuring that the Swab Valve and the line to the gauge are open.

4) Close UMV and LMV, if fitted.

5) Open FWV.

6) Bleed off pressure between the Location Valve and the Wellhead through the fixed flexible bleed line.

7) Close KWV and FWV.

8) Replenish Tree Cavity pressure by either pumping or cycling UMV and LMV, if fitted.

9) Record Test Start pressure at the swab pressure gauge in the WIMS Checklist.

10) Measure the pressure drop in the enclosed tree cavity over 10 minutes using a gauge known to be accurate.

a. Monitor the pressure rise in the enclosed flow line section between the FWV and the Location Valve using the Flow line Pressure Gauge.

Note:If the pressure rise observed on the monitoring gauge exceeds the pressure rise corresponding to the Allowable Leak Rate, specified in the Well Failure Model (Allowable leak rate sheet), the FWV is recorded as a Fail; such a result also suggests that the combination of UMV/ LMV is also a Fail. In this instance, grease all valves and re-test FWV. If the result is the same then the Well Services Supervisor or the Asset Well Integrity Engineer must be informed before taking any further action.11) Record Test Finish pressure in the WIMS Checklist.






Task CodeSVW


1) Close SV.

2) Open UMV and LMV.




6) Measure the pressure build-up above the SV over 10 minutes using a gauge known to be accurate.







Task CodeKWVIW



2) Bleed KWVI downstream cavity and install a pressure gauge and double block and bleed system.

3) Re-pressurize the tree body if required by the chosen method and allow the pressure in the tree body to stabilize.










Well Type 2 wit

Task CodeUMVW


1) Close UMV












Well Type 2 wit

Task CodeLMVW

Task Decription Function/ Leak-off test Lower Master Valve (if fitted)

1) Close LMV.

2) Open UMV.

3) Open the bleed facility to bleed the Tree Cavity to as near zero as possible; maintain some positive pressure on the gauge.









2.1.3.4.9 WIT Task Function/ Leak-off test the Down-Hole Safety Valve

Well Type 2 wit


Task Decription Function/ Leak-off test Down-Hole Safety Valve e.g. SCSSSV

1) Open the LMV or UMV, record the CITHP.

2) Close the SCSSSV by trip function locally.

3) Open the FWV.


5) Close FWV.

6) Bleed off the remaining pressure through the secured flexiline.




10) Measure the pressure build-up in the tubing and the Tree Cavity over 30 minutes using a gauge known to be accurate; use the Well Failure Model Leak Rate Equation to determine if the leak rate is acceptable.



13) Whilst conducting the above build-up survey, confirm (e.g. by looking, listening and feeling) that there is no communication with the reservoir through the Control Line.

14) If the first test fails, cycle the valve and re-test it until the test results in a Pass or no improvement in results is seen. Ensure that the pressure across the SCSSSV is equalized before cycling. A pump may be required to obtain pressure above the SCSSSV.

15) Record the final test (last test carried out) result in the WIMS WIT Checklist including the Start and the Finish pressure and the Number of Tests done.


17) Maintain (e.g. grease or lubricate) all Tree Valves.

18) Re-open the SCSSSV.

19) Adjust the Control Line pressure to within the limits stated and record the pressure in the WIT Checklist. Recommend control line pressures, but do not adjust at the Framo Panel.

Notes:1.)WIMS Master Data for the well will be adapted to include allowable leak rates for SSSVs. So check WIMS to confirm the calculated allowable leak rate!

2.) Where a well is plugged or suspended, first carry out the Tree Valve Leak-off test using any pressure that has built up above the plug. Then bleed off the pressure above the plug, close in the bleed and carry out and extended (4 hour) inflow test on the plug recording the results at hour average over the test period (i.e. one eighth of the observed rise over the 4 hour test period). Simply cycle and maintain the tree valves where no pressure is initially seen above the plug.

3.) For SCSSSVs with no equalizing feature it will be necessary to equalise the pressure across the valve with inhibited sea water by means of a high pressure pump hooked up to the kill wing valve.


Well Type 2 wit

Task CodeMAVW/ MTVW





2.1.4 Well Type 3 (Gas lift Wells)

The Testing Frequency as per SP-2017, Well Failure Model2.1.4.1 Safety Precautions2.1.4.1.1 Permit to Work











2. Valve leak test durations are 10 minutes.

3. If CITHP drops to below the required P (1.2 times the Allowable Leak Rate) during the test, then replenish CITHP using gas lift pressure.

Note:Valve tests shall be carried out with gas lift supply isolated to prevent annulus overpressurization or bullheading into the reservoir.

4. FWV and KWV tests can be carried out at the same time to reduce deferment but SV should be monitored during test to see any decay.








Task CodeELCW /CAPW






Well Type 3 wit

Task CodeVIW






Well Type 3 wit



1) Shut in production at the choke, close FWV, UMV and LMV to isolate the wellhead from the reservoir and the flow line from the gas lift supply. Use a hand pump and control line fluid to ensure that all pressure reading lines, i.e. those in contact with well fluid, are free from obstruction.





Attention!



Task CodeFWVIW

Task DeScription Function / leak-off test Flow Wing Valve

1) Shut in production at the choke (if fitted) and the FWV.

2) Isolate the gas lift supply by closing the annulus valves.

3) Close the Location Valve.



Note:Monitoring CITHP during FWV test makes test pressure decay noticeable.

6) Bleed off pressure between the Location Valve and the Wellhead through a fixed flexible bleed line into a portable waste drum.

7) Record Test Start pressure at the flow line pressure gauge in the WIMS Checklist.

8) Measure the build-up in the flow line between the FWV and Location valve using the flow line Pressure Gauge.

Note:If the integrity of the FWV is suspect continue the Integrity test with the Master Valve.

9) Record Test Finish pressure in the WIMS Checklist.






Task CodeSVW


1) Close SV.











Task CodeKWVIW













Well Type 3 wit

Task CodeUMVW


1) Close UMV












Well Type 3 wit

Task CodeLMVW


1) Close LMV.

2) Open UMV.











Well Type 3 wit

Task CodeMAVW/ MTVW





2.1.5 Well Type 4 (Steam Injection Wells)

The Testing Frequency as per SP-2017, Well Failure Model2.1.5.1 Safety Precautions2.1.5.1.1 Permit to Work












3. FWV and KWV tests can be carried out at the same time to reduce deferment but SV should be monitored during test to see any decay.

4. Where a valve to be tested is NOT fitted, omit the respective task.5. The well to be tested must be closed in well in advance prior to the test in order to cool down sufficiently to allow intervention by personnel. Experience shows that the required cooling period may vary between over night in the winter and up to three days in the summer. This must be taken into account when planning a WIT or SIT on a steam well.

6. The test pressure must only be replenished from the reservoir (by opening the Master Valves). If a fluid was used and subsequently accidentally trapped in any valve cavity, temperature increase during production could lead to fluid evaporation, associated with an uncontrolled pressure increase. This in turn could lead to compromising the well integrity.





Task CodeELCW /CAPW






Well Type 4 wit

Task CodeVIW






Well Type 4 wit



1) Shut in production at the choke, close FWV, UMV and LMV to isolate the wellhead from the reservoir and the flow line from the gas lift supply. Use a hand pump and control line fluid to ensure that all pressure reading lines, i.e. those in contact with well fluid, are free from obstruction.





Attention!



Task CodeFWVIW


Note:This method assumes that the Master Valve provides a leak-tight seal.

1) Shut in production at the choke (if fitted) and the FWV.

2) Close the Location Valve.



Note:Monitoring CITHP during FWV test makes test pressure decay noticeable.

5) Bleed off pressure between the Location Valve and the Wellhead through a fixed flexible bleed line into a portable waste drum.

6) Record Test Start pressure at the flow line pressure gauge in the WIMS Checklist.

7) Measure the build-up in the flow line between the FWV and Location valve using the flow line Pressure Gauge.

Note:If the pressure rise observed on the monitoring gauge exceeds the pressure rise corresponding to the Allowable Leak Rate, specified in the Well Failure Model (Allowable leak rate sheet), the FWV is recorded as a Fail; such a result also suggests that the Location Valve is also a Fail. In this instance, grease all valves and re-test FWV. If the result is the same then the Well Services Supervisor or the Asset Well Integrity Engineer must be informed before taking any further action.8) Record Test Finish pressure in the WIMS Checklist.






Task CodeSVW


1) Close SV.











Task CodeKWVIW










b. Flush the Valve Cavity after two failed tests using flushing liquid.



Well Type 4 wit

Task CodeUMVW


1) Close UMV












Well Type 4 wit

Task CodeLMVW


1) Close LMV.

2) Open UMV.










2.1.5.4.9 WIT Task Function/ Leak-off test Downhole Plugs (if fitted)

Well Type 4 wit


Task Decription Leak-off test Down-Hole Plug (if fitted)

1) Open the LMV or UMV, record the CITHP.

2) Open the FWV.


4) Close FWV.

5) Bleed off the remaining pressure through the secured flexiline.




9) Measure the pressure build-up in the tubing and the Tree Cavity over 4 hours as described in the note below. Use the Well Failure Model Leak Rate Equation to determine if the leak rate is acceptable.

Note:Where a well is plugged or suspended, first carry out the Tree Valve Leak-off test using any pressure that has built up above the plug. Then bleed off the pressure above the plug, close in the bleed and carry out and extended (4 hour) inflow test on the plug recording the results at hour average over the test period (i.e. one eighth of the observed rise over the 4 hour test period). Simply cycle and maintain the tree valves where no pressure is initially seen above the plug.




Note:WIMS Master Data for the well will be adapted to include allowable leak rates for any plugs fitted. So check WIMS to confirm the calculated allowable leak rate!


Well Type 4 wit

Task CodeMAVW/ MTVW





2.1.6 Well Type 5 (Sub-hydrostatic, pumped wells)

Pumped water supply wells are included in this well type.

The Testing Frequency as per SP-2017, Well Failure Model2.1.6.1 Well type specific risks

Flow is controlled electrically rather than hydraulically Peforming a test with the pump running on the SV and KWV.2.1.6.2 Safety Precautions2.1.6.2.1 Permit to Work









4) Ensure that the pump has been electrically isolated prior to start of the WIT in accordance with PR-1172, Permit to Work Procedure and SP-1104, Electrical Safety Rules.


1. On pumped wells, pressure is unlikely to exist for testing purposes; the primary purpose of a WIT on this well type is therefore to assess the condition and maintain the valves.2. The allowable Leak Rates for Valves are listed by valve size in the Allowable leak rates tab of SP-2017, Well Failure Model.


4. Where a valve to be tested is NOT fitted, omit the respective task.5. The tests and the work to be carried out are defined, for each individual well type, in the Well Failure Model, in the worksheet titled Well Integrity Testing/ Maintenance Matrix (ensure work is carried out based on the approved version of the Well Failure Model).



2.1.6.5 Testing

2.1.6.5.1 WIT Task Adjust Stuffing Box Seals

Well Type 5 wit

Task CodeSPSA

Task Decription Adjust Stuffing Box Seals

This task is specific to rod-pumps

1) Monitor the external leakage from the stuffing box with the pump running.

2) If the Leak rate exceeds those specified in the Well Failure Model, stop the pump and adjust the stuffing box, this to give optimum sealing capability without binding.

3) Restart the pump and re-check leakage.

4) Continue steps 2 to 3 until the observed leak rate is within limits or no further improvement is achieved.

5) Record the result as Pass or Fail in the WIMS Checklist.

6) Inspect the vitraulic joint and report any condition degradation in the Free Text box in the WIMS Checklist.

7) Inspect the polished rod and report any condition degradation in the Free Text box in the WIMS Checklist.

2.1.6.5.2 WIT Task Carry out External Leak TestWell Type 5 wit

Task CodeELCW /CAPW






Well Type 5 wit

Task CodeVIW






Well Type 5 wit



1) This test shall be carried out with the pump running.

2) Use a hand pump and control line fluid to ensure that all pressure reading lines, i.e. those in contact with well fluid, are free from obstruction.





Attention!



Task CodeSVW


Note:This test applies to pumped wells without rods

1) This test shall be carried out with the pump running!

2) Close SV.


4) Close in the bleed point and install Test Manifold.







The pump must be isolated for greasing and/ or flushing!



Task CodeKWVIW


Note:This test applies to all types of pumped wells1) This test shall be carried out with the pump running!

2) Close KWV.

3) Bleed KWV downstream cavity.

4) Close in the bleed point and install Test Manifold.


6) Measure the pressure build-up above the KWV over 10 minutes using a gauge known to be accurate.





The pump must be isolated for greasing and/ or flushing!



Task CodeFWVIW


1) Shut down and electrically isolate the pump

2) Function and maintain the valve in line with the relevant Maintenance Guide.

a. Enter Pass in the WIMS Checklist where the valve functions correctly.

b. Enter Fail in the WIMS Checklinst where the valve fails to function and where this condition cannot be rectified by the test crew.


Well Type 5 wit

Task CodeUMVW


Warning: Do NOT function any Master Valve on a rod-type pumped wellA: Task Description for non-rod type wells



b. Enter Fail in the WIMS Checklinst where the valve fails to function and where this condition cannot be rectified by the test crew

B: Task Description for rod type wells

1) Close the valve a maximum of 2 turns to confirm the valve is not seized. Do NOT apply more than 2 turns to the valve as the valves gate may impinge on the rod.

2) Maintain the valve in line with the relevant Maintenance Guide.

3) Re-open the valve.

2.1.6.5.9 WIT Task Function/ Leak-off test the Upper Master Valve LMV

Well Type 5 wit

Task CodeLMVW


Warning: Do NOT function any Master Valve on a rod-type pumped wellA: Task Description for non-rod type wells



b. Enter Fail in the WIMS Checklinst where the valve fails to function and where this condition cannot be rectified by the test crew

B: Task Description for rod type wells

1) Close the valve a maximum of 2 turns to confirm the valve is not seized. Do NOT apply more than 2 turns to the valve as the valves gate may impinge on the rod.

2) Maintain the valve in line with the relevant Maintenance Guide.

3) Re-open the valve.


Well Type 5 wit

Task CodeMAVW/ MTVW




Note:To ensure the valves ongoing operability, it is vital that all valves (especially tree valves) are maintained in line with Manufacturers Instructions irrespective of the test result.

3) Hand over the well to Production Operations for De-isolation and re-start (if required).

2.1.7 Well Types 6 and 7 (Water Injection/ Disposal wells with/ without tubing)

The Testing Frequency as per SP-2017, Well Fai

PR-1047 Well Integrity Maintenance

Documents

Transcript of PR-1047 Well Integrity Maintenance