Development / installation of permanent downhole capillary Gas Well De-Liquification Workshop Denver, Colorado February 28 - March 2, 2005 injection facilities in gas wells with 07/03/2005 File Title Copyright: Shell Exploration & Production Ltd. sub-surface safety valves Eelco Bakker, Dick Klompsma, Hans van Dijk, Gerben Wieldraaijer Nederlandse Aardolie Maatschappij (Shell Exploration and Production in The Netherlands)
Field example 150 0.4 Hourly 19/12/00 00:00:00 131.25 0.35 112.5 0.3 pressure 93.75 0.25 75 56.25 37.5 0.2 0.15 0.1 flowrate Sudden drop in flow, result of liquids building up and well no longer capable of flowing or flowing intermittently 18.75 0.05 0 0 3-12-00 4-12-00 5-12-00 6-12-00 7-12-00 8-12-00 9-12-00 10-12-0011-12-0012-12-0013-12-0014-12-0015-12-0016-12-0017-12-0018-12-00
90 150 0.6 Field example 75 125 0.5 Hourly 0.09 20-09-02 08:13:56 88.00 47.30? Drop in flowrate L15FA1-CCFI01.PV 0.00 MILJ.NM3/D L15FA1-CCPC1.PV 95.00 BARG L15FA1-CCTI01.PV 35.40 DEG.CELC. 60 100 0.4 45 75 0.3 Drop in temperature while not flowing 30 50 0.2 15 25 0.1 0 0 0 16-9-02 17-9-02 17-09-02 09:41:39 18-9-02 19-9-02 20-9-02
Solutions background European legislation requirement for surface- and subsurface safety valves (SSV + SC-SSSV) No equipment (SC-SSSV+capillary) readily available within industry Conceptual ideas only In-house idea Shell patent (TS 9521 EPC) Principle: use existing C/L to pump down foam solution + modify SSSV to hang off capillary 2-tier follow-up In-house development use of existing equipment / components Foam Insert Sleeve (FIS concept) Request to Halliburton (main supplier completion eqpt.) to modify existing valve (Chemical Injection Safety Valve - CISV) Design criteria» Low cost / standard components / minimal mods existing equipment / cover all tubing sizes 3 ½ 9 5/8 with main focus on 3 ½ and 5 1/2.
Foam Insert Sleeve (FIS) concept Auxiliary equipment 1.Wire-line BOP for sleeve (similar as for SC-SSSV) 2.CT Quad BOP for control valve / hanger 2 ID BOP with slip-type rams for ¼ Existing SV landing nipple (part of existing completion) Sleeve with new SV landing nipple profile and by-pass for foam from C/L inlet to control valve/hanger capillary Capillary string Control valve (hanger) installed at bottom of sleeve
FIS - equipment Standard RQ running / GS pulling tools Guide sleeve Insert sleeve Standard Insert safety valve SV Control valve + hanger
Pull SC-SSSV FIS installation sequence Install insert nipple Install guide sleeve RIH 1/4 capillary + space-out Hang-off string in BOP Cut string & connect to Hanger Install Hanger in Insert Nipple Pull Guide sleeve Install and test SC-SSSV WL operation, wire 0.125 Start Foam Injection CT operation
Begin situation: 5 4 1 2 3 4 Pull SC-SSSV Install insert nipple RIH 1/4 capill. + space-out Hang-off string in BOP 3 6 5 6 Cut string & connect to hanger Install hanger in insert nipple 7 Install and test SC-SSSV 1 2 7
Begin situation: End situation SC-SSSV installed in tubing SV-LN, operated via ¼ controlline SC-SSSV installed in sleeve, foam injection + SV operations via ¼ controlline
time Time (P tbg @ SV depth + P SV full opening P hydraulic C/L + safety margin)
Chemical Injection Safety Valve concept (Halliburton - CISV) Auxiliary equipment 1.Full size Modified BOP for modified SV including rams to hold capillary during make-up existing for 3 ½ size Existing SV Connection capillary to SV Clamp to hold down capillary Capillary string connected to SV
Pull SC-SSSV CISV installation sequence Perform Dummy run RIH 1/4 Capillary string Hang-off string in BOP Cut string & connect SC-SSSV Install SC-SSSV+coil in LN Test SC-SSSV Start Foam Injection WL operation CT operation
Foam Inlet ports CISV equipment (Halliburton) Connection capillary to safety valve By-pass allowing foamer to capillary Capillary clamp construction Conventional Flapper valve Courtesy Halliburton
FIS versus CISV Key differences Halliburton CISV FIS SV integrated with chemical injection Full size capillary deployment BOP s required for different valve sizes System acts as 1 pressure vessel, SV operating pressure driven by depth / wellhead pressure drives setting of downhole injection valve high operating pressure entire system. Pressure range, 200 bar surface, up to 600 bar downhole Possible to install / pull SC-SSSV independent from capillary injection system flexibility in sizes ( 5-9 5/8 ) only 1 size capillary deployment BOP required 2 operating vessels, operating pressure setting control valve/hanger independent of SV operating pressure lower operating pressures Pressure range, 200 bar surface, up to 300 bar downhole
QA / QC item criterion Ensured by All safety critical equipment installed in the well to meet standard requirements (RQ / XO lockmandrels / 2.75 Halliburton FXE wireline retrievable SV) In line with API - 14A 1&2 Critical seals Viton / Chemraz Sh. 90 spec Foam selection Stability / compatibility No outstanding issues from reviews Installation /running procedures of capillary & modified safety valve or modified sleeve+ safety valve Safety Impact of foam systems No outstanding issues after dry run No significant increase in overall risk levels Materials send to location certified (workshop testing acc procedures) function & inflow testing once installed before well taken into production tested in NAM lab (autoclave) tested in NAM lab (autoclave) Multidisciplinary HAZID / HAZOP review (WS/ PT/ Ops/ PC / Eng) All issues closed-out after Zuidbroek testing QRA / RAM approach
Risks mitigation Impact foam injection on well related safety 3 different steps HAZID running & operation of systems Qualitative analysis (RAM approach) Semi-quantitative analysis HAZID running & operation of systems Key challenges identified: Compatibility foam seals Foam stability Compatibility foam solution hydraulic oil Interaction existing ESD-systems Impact on (production) surface facilities Familiarisation with new equipment / services.
Risk Assessment Matrix (RAM) Combines scenario consequence with its probability Experience is used to determine both classifications Focuses on the high impact scenario Not a lot of granularity for comparison Increasing risk The level of control should depend on the level or risk! worst case Likelihood case
Quantitative Assessment Objective Estimate the annual blowout and/or release rates for each of the designs and compare with current background rate Results Industry accepted blowout frequencies (SINTEF, EUB) and failure rate for installed equipment (Wellmaster / Oreda) Intervention frequencies based on actual (historical) data No significant differences between without foam / with foam injection No impact on location related risk level (effect of exposure included!!)
Field installations COV-55 WAV-18 MKZ-3 Tubing 5 1/2" 18#, L-80 Cr-13 3 1/2", 10,2#, CS 7", 32#, Cr-13 Injection valve depth 2850 meter 1760 meter 3880 meter Perforations 2762-3161 meter 1756-1820 meter 3838-3934 meter Deviation @ reservoir 20 42 45 SC-SSSV depth 301 meter 85 meter 103 meter Concept 4.562" FIS 2.75" CISV 5.875" FIS Cap. Type 1/4" 0.035 " Inc. 625 1/4" 0.035 " Inc. 625 1/4" 0.035 " Inc. 625
Learnings Extensive equipment testing incl. dry runs in test well with capillary paid of Equipment behaviour / pressure setting control- and injection valves Operational procedures Accidentally capillary cutting fishing successful Material selection equipment incl. seals critical Foamer composition Well conditions Functioning downhole injection valve critical Accurate dosing of chemicals to optimise well lift Impact on safety valve operations / behaviour Campaign approach All systems tested and installed (1*3 ½, 1 * 5 1/2, 1* 7 ) Further investigations for simplifications future installations
Contributors & acknowledgements Shell Chris Kuyken Hendrik Hindriks Dick Klompsma Hans van Dijk Gerben Wieldraaijer Rob Eylander