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Home My WebLink AboutCO 335Conservation Order Cover Page XHVZE This page is required for administrative purposes in managing the scanning process. It marks the extent of scanning and identifies certain actions that have been taken. Please insure that it retains it's current location in this file. Conservation Order Category Identifier Organizing RESC~~'' DIGITAL DATA j~ Color items: [] Diskettes, No. [] Grayscale items: [] Other, No/Type [] Poor Quality Originals: [] Other: NOTES: OVERSIZED (Scannable with large plo~ner) [] Other items OVERSIZED (Not suitable for plotter/scanner, may work with ~'/" Logs of various kinds E.~,' [] Other BY: ~ MARIA Scanning Preparation TOTAL PAGES,~ ~ BY: ~ MARIA Production Scanning Stage I PAGE COUNT FROM SCANNED DOCUMENT: YES __ NO BY: Stage 2 IF NO IN STAGE 1, PAGE(S) DISCREPANCIES WERE FOUND: __ YES NO (SCANNING IS COMPLETE AT THIS POINT UNLESS SPECIAL ATTENTION IS REQUIRED ON AN INDIVIDUAL PAGE BASIS DUE TO QUALrrY, GRAYSCALE OR COLOR IMAGES) General Notes or Comments about this Document: 5/21/03 ConservOrdCvrPg.wpd • • INDEX CONSERVATION ORDER NO. 335 Baker #28 1.) Apri14, 1994 UNOCAL Requests a Temporary Waiver 2.) Apri16, 1994 Notice of Public Hearing, Affidavit of Publication 3.) April 18, 1994 Piping and Instrumental Diagram and Hazop Summary 4.) April 19, 1994 Application for Temporary Waiver Conservation Order No. 335 Re~ STATE OF ALASKA OIL AND GAS CONSERVATION COMMISSION 3001 Porcupine Drive Anchorage, Alaska 99501-3192 The Application of Union Oil Company of ) California (Unocal) requesting temporary ) waiver of 20 AAC 25.265(a)(2) to allow ) production ofMGS 17595 No. 28 well. ) Conservation Order No. 335 Middle Ground Shoal Oil Field MGS 17595 No. 28 well. April 29, 1994 IT APPEARING THAT 1. By letter dated April 4, 1994, Union Oil Company of California (Unocal) requested temporary waiver of 20 AAC 25.265(a)(2)to allow production of MGS 17595 No. 28 well. 2. A notice of opportunity for public hearing was published in the Anchorage Daily News on April 6, 1994. 3. No protests were filed with the Commission. FINDINGS: A well with an offshore location must be equipped with a Commission approved fail safe automatic surface control subsurface safety valve (SSSV) system, unless another type of subsurface valve is approved by the Commission; this valve must be in the tubing string and located below the mud line, permafrost, or at some other depth as may be required; the valve must be capable of preventing an uncontrolled flow. 20 AAC 25.265(a)(2). , The MGS 17595 No. 28 well was completed with a dual 3.5 inch tubing string, a Kobe bottom hole assembly (BHA) and a hydraulic pump located at 8436 feet MD. The well is not equipped with a packer. . The MGS 17595 No. 28 well is completed in a similar manner to other recently completed or recompleted Middle Ground Shoal wells, which are not capable of flow to the surface without assist from artificial lift. Unocal anticipated that the MGS 17595 No. 28 well would not be capable of unassisted flow to the surface. . Initial testing ofMGS 17595 No. 28 well shows the well is capable of unassisted flow to the surface from perforations in the 'A', 'B, C, D' and 'E, F, G.' pools. The well appears to have been completed in at least one oil zone with sufficient pressure and associated gas to flow to the surface. 5. The MGS 17595 No. 28 well has been shut-in since April 1, 1994 following initial testing. Conservation Order 335 Middle Ground Shoal Oil Field Page 2 April 29, 1994 . Unocal proposes to install a Baker "XVE" valve in the Kobe BHA. The Baker "XVE" valve is a standard flapper-type SSSV that allows well fluid to travel up the flow string when the flapper is held open by energizing pressure in the power oil string and prevents flow if energizing pressure is removed. The Baker "XVE" valve can be installed without removing the tubing string. 7. Installation of a packer in the MGS 17595 No. 28 well would require killing the well and pulling the existing completion. 8. MGS wells show a history of formation damage by completion and workover fluids. 9. Without a packer, flow up the MGS 17595 No. 28 well annulus is possible in the event of a catastrophic failure or loss of wellhead or surface safety equipment. 10. Installation of a packer would reduce the efficiency of the artificial lift system by forcing gas production through the pump and tubing instead of allowing venting up the annulus. With a packer in the well, production rates would be restricted, reducing ultimate recovery of oil and gas from the MGS field. 11. Unocal expects the MGS 17595 No. 28 well to experience rapid pressure decline and anticipates the flowing condition of the well to be of short duration. 12. The Middle Ground Shoal oil field was discovered in 1962; production began in the 'A' pool in 1967 and in the 'E, F, G' and 'B, C, D' pools in 1965. 13. Initial pressure was 2485 psig at 5500 feet TVD SS for the 'A' pool, 2793 psig at 6000 feet TVD SS for the 'B, C, D' pool and 3975 psig at 9200 feet TVD SS for the 'E, F, G' pool. 14. Before initiation of waterflood, pressure decline in each pool was rapid. By 1969, pressure had declined to 1600 psig in the 'A' pool (Well No. 11) and 1618 psig in the 'B, C, D' pool (Well No. 6). 15. Waterflood operations appear to have restored pressure to near original pressure in each pool. Pressure surveys for the 'A' pool taken in wells No. 17 and No. 6 during 1993 show pressure of 2502 psig and 2161 psig, respectively. Pressure survey for the 'B, C, D' pool taken in wells No. 16 and No. 17 during 1991 show pressures of 2925 psig and 1870 psig, respectively, and 4593 psig and 4843 psig for the 'E, F, G' pool in wells No. 15RD and No. 11. 16. The injection of large volumes of water into each pool results in water cut ratios too high to allow previously completed wells in each pool to flow to the surface unaided by artificial lift. 17. Waterflood operations have been discontinued in the 'A' pool. Conservation Order 335 Middle Ground Shoal Oil Field Page 3 April 29, 1994 18. A pressures gradient survey run in MGS 17595 No. 28 well on April 17, 1994 measured 2462 psig at 5178 feet TVD SS, which extrapolates to 2481 psig at the top of the 'A' pool perforations at 5406 feet TVD SS. 19. Initial well testing of MGS 17595 No. 28 well shows a higher than normal gas-oil ratio, GOR was estimated to range between 2200 scf/bbl and 4500 scf/bbl. 20. Unocal estimates the production potential of the MGS 17595 No. 28 well to be approximately 1000 to 1800 bbl of oil per day. 21. Original GOR was 1000 scf/bbl for the 'A' pool, 650 scf/bbl for the 'B, C, D' pool, and 381 scf/bbl for the 'E, F, G' pool. 22. Unocal proposes to monitor pressure decline during the term of any waiver granted in response to its request, and states that six months of production and pressure data should be sufficient to determine the length of any extension of the waiver, if necessary. 23. If the waiver is approved, Unocal proposes to produce the well through its own automatic surface shut-in valve and separation and testing equipment with high and low pressure and level shut-down capability. Standard Hi-Low pressure shut-in valves will be installed at the wellhead on both the tubing and annulus. The Hi-Low tubing safety valve will be set at 600 psi and 300 psi, respectively, and the annulus valve at 3000 psi and 300 psi. CONCLUSIONS: . The Baker "XVE" valve serves as a secondary safety system to prevent accidental flow up the tubing in the event the surface safety valve fails, but does not satisfy the requirements of 20 AAC 25.265(a)(2) unless a packer is installed in the well to prevent flow up the annulus. 2. The MGS 17595 No. 28 well cannot be produced without modification to its current completion unless the requirements of 20 AAC 25.265(a)(2) are temporarily waived. 3. Installation of a packer will require killing the well, which may jeopardize well productivity and ultimate recovery from MGS. 4. Producing the MGS 17595 No. 28 well for six (6) months should be sufficient to acquire production and pressure data to accurately assess the flow potential of the well. . The high GOR of the MGS 17595 No. 28 well is not representative of MGS wells, and is likely the result of encountering a gas leg in the 'A' pool. The high level of associated gas may be responsible for the well's capacity for unassisted flow to the surface. The gas leg is expected to deplete rapidly once production begins. 6. Based upon performance of past MGS wells and limited pressure maintenance, rapid pressure decline is expected for the MGS 17595 No. 28 well. Conservation Order 33 5 Middle Ground Shoal Oil Field Page 4 April 29, 1994 . Installation of surface and downhole safety equipment as proposed by Unocal is a reasonable and prudent alternative to the requirements of 20 AAC 25.265(a)(2) and is consistent with sound engineering practices. 8. With the additional safety precautions, temporary waiver of 20 AAC 25.265(a)(2) for a period of six (6) months should not cause waste nor jeopardize ultimate recovery. NOW, THEREFORE, IT IS ORDERED THAT the requirements of 20 AAC 25.265(a)(2) are temporarily waived for a six months period for the MGS 17595 No. 28 well. This waiver may be extended by Administrative Approval for an additional six month period upon proper showing to the Commission that pressure is declining in the well and that in all likelihood the well will no longer be capable of flow to the surface prior to expiration of the extension or to allow installation of equipment sufficient to meet the requirements of 20 AAC 25.265(a)(2). The operator shall check and record tubing, power oil and casing pressures at least twice each day. Copies of pressure records and pressure surveys shall be submitted to the Commission monthly during the waiver period. The flow line on the tubing-casing annulus will be equipped with a locked valve to prevent inadvertent flow from the annulus. DONE at Anchorage, __. ~~iDavid V~ Jc~h~tOn' Russell A. Douglass, Comnffssioner AS 31.05.080 provides that within 20 days after receipt of written notice of the entry of an order, a person affected by it may file with the Commission an application for rehearing. A request for rehearing must be received by 4:30 PM on the 23rd day following the date of the order, or next working day if a holiday or weekend, to be timely filed. The Commission shall grant or refuse the application in whole or in part within 10 days. The Commission can refuse an application by not acting on it within the 10-day period. An affected person has 30 days from the date the Commission refuses the application or mails (or otherwise distributes) an order upon rehearing, both being the final order of the Commission, to appeal the decision to Superior Court. Where a request for rehearing is denied by nonaction of the Commission, the 30 day period for appeal to Superior Court runs from the date on which the request is deemed denied (i.e., 10th day after the application for reheating was filed). Unocal Energy I Unocal Corporatk 909 West 9th Ave Anchorage, Alask Telephone (907); Facsimile 263-76! UNOCAL ) Kevin A. Tabler Land Manager Alaska April 19, 1994 Mr. Russell Dou~ .... Alaska Oil and Gas Conservation Commission 3001 Porcupine Drive Anchorage, Alaska 99501 Dear Mr. Douglass: Re: Baker #28 Well - Application Temporary Waiver [20 AAC 25.265(2)] for Enclosed please find the remaining supplemental information provided with respect to Unocal's application for a temporary waiver. This information, together with the PaID and Hazop Summary delivered to your office yesterday, should complete the additional information Unocal agreed to provide in our application dated April 4, 1994. If you have any questions, please contact me at (907)263-7877 or Mr. S. Kurt Bair at (907) 263-7646 for technical information. Enclosure Very truly yours, Elizabeth A.R. Shepherd Project Landman Gas Cons. Commissiot~ Anchorage Unocal Energy Resourcel~ rision Unocal Corporation 909 West 9th Avenue, P.O. Box 196247 Anchorage, Alaska 99519-6247 Telephone (907) 276-7600 Facsimile 263-7698 UNOCAL KevinA. Tabler Land Manager Alaska April 19, 1994 Mr. Russell Douglass Alaska Oil and Gas Conservation Commission 3001 Porcupine Drive Anchorage, Alaska 99501 Re: Baker #28 Well - Application for Temporary Waiver [20 AAC 25.265(2)] Dear Mr. Douglass: Enclosed please find the remaining supplemental information provided with respect to Unocal's application for a temporary waiver. This information, together with the P&ID and Hazop Summary delivered to your office yesterday, should complete the additional information Unocal agreed to provide in our application dated April 4, 1994. If you have any questions, please contact me at (907)263-7877 or Mr. $. Kurt Bair at (907) 263-7646 for technical information. Enclosure Very truly yours, .~ ...... ? , ,. ,~ ~ /.' <. ./ .......... ,.,,," ~;,~,. , Elizabeth A.R. Shepherd Project Landman ~PR ~0 ~994 Gas Cons. C0mmlssl0~ Anchorage SUPPLEMENTAL DATA IN SUPPORT OF UNOCAL'S REQUEST FOR TEMPORARY WAIVER OF 20 AAC 25.265(2) TO ALLOW PRODUCTION OF MGS 17595 NO. 28 i · TRICO INDUSTRIES DIAGRAM OF PROPOSED 3" X 2.312 BAKER "XVE" SSSV IN 3" KOBE B DOUBLE BHA. (ATTACHMENT #1) The Kobe BHA is the receptacle for the hydraulic pump located at 8436', at the bottom of the dual 3.5" tubing strings. The Baker "XVE" valve is a standard flapper-type SSSV installed in a crossover/sealing assembly that allows well fluid to travel up the flow string when the flapper is held open by energizing pressure in the power oil string and prevents flow if the energizing pressure is removed. A lock-down device (shown with fishing neck) is run on top of the assembly to prevent well pressure from pushing it up the hole. 2. WELLBORE DIAGRAM (ATTACHMENT #2) This diagram shows the location of the various casing strings, the dual 3.5" tubing strings, the hydraulic pump BHA, and the perforations and perforating guns hanging in the well. The guns were left in the well to avoid having to kill the well to retrieve them. A more detailed wellbore diagram with casing weights and grades and cementing information is being prepared. 3. MUD LOG (ATTACHMENT #3) The mud log shows the good hydrocarbon indicators that registered in each of the sections of the well that were perforated. Especially good oil and gas shows were logged through the "A" and "B" zones from 8546' to 9175' (5406' to 6008' TVD). Unocal believes that the largest portion of the oil and gas that flowed into the well during initial testing came from these .intervals. 4. PRESSURE HISTORY OF THE TYONEK INTERVALS AT BAKER "A" ZONE: Amoco data lists the reservoir pressure at discovery in 1964 at 2485 psig-'at 5500' datum, or a 0.45 psi/ft gradient. Pressure in the handful of "A" zone wells declined rapidly with production (by February 1969 "A" zone pressure had fallen to 1600 psi at Well #11) and water injection commenced in mid 1969. In 1972, the pressure at wells #9 and #12 was measured at 2857 psig and 2367 psig respectively. That same year, a pressure buildup at well #4 yielded only 1221 psig, showing that pressure maintenance MGS 17595 #28 - SUPPLEMENTAL DATA Page 2 had not yet effected that well. Pressure maintenance continued over the years and in 1993, pressure surveys in well #17 and well #6 measured the datum pressure at 2502 and 2161 psig respectively. Well #17 was open in the combined "A" and "BCD" pools at the time of the test. High water cuts result in wellbore gradients that prevent these wells from flowing unassisted. "BCD" ZONE: Initial pressure in the "BCD" zone was calculated at 2793 psig at 6000' datum, or a 0.466 psi/ft gradient. Pressure decline was swift until the establishment of pressure maintenance in 1969. The pressure was as low as 1618 psig in well ~6 by April of 1969. By 1975, the pressure had only recovered slightly to 1767 psig in well #6. More recent tests in well ~16, 2925 psi in 1991, and well ~17, 1870 psi in 1991, show that the reservoir pressure varies substantially from well to well in the "BCD". However, none of the existing wells completed in the "BCD" is capable of flowing, due to water loading up in the wells. "EFG" ZONE: No separate pressure data exist for the Tyonek (E and F ) portion of this pool. Pressure maintenance is believed to have returned the average pressure in the pool to near the original 3975 psi at 9200'. Water injection falloff tests in 1993 show pressures at injection points between 4593 and 4843 psi at 9200'. In 1991, static pressures in Well # 15RD and ~11 were 4132 psi and 3718 psi after very long shut in periods. Once again, the presence of large amounts of water in the wells with more pressure makes them incapable of flowing unassisted. · HISTORY OF FORMATION DAMAGE DURING WORKOVER OPERATIONS (ATTACHMENT #4 ) Over the life of the Middle Ground Shoal and Granite Point oilfields it has been observed that the Tyonek formations are sensitive to formation damage by completion and workover fluids. The wells have been particularly susceptible to damage by completion brines. It is believed that the primary damage mechanism is the disturbance of formation clays by non-native waters. Disturbed clay particles swell and detach from the walls of the pore spaces and subsequently bridge off in formation pore throats restricting the productive capacity of the reservoir rock. In the mid 1970's Amoco began to use oil based completion fluids at-Middle Ground Shoal and Granite Point Fields to mitigate formation damage during workover operations. Diesel was used in cases where its pressure gradient ( 0.34 psi/ft) was adequate to control formation pressure. Unocal has continued the us~~ diesel in applicable situations. ~tEIVED n~ 2 0 1994 ..... ,~os~ ~,~ & Gas Cons. Commissior~ Anchorage MGS 17595 ~28 - SUPPLEMENTAL DATA Page 3 Currently, weighted brines remain the only option for Unocal to control normal or higher than normal formation pressures in Cook Inlet workover and completion operations. Attachment #4 is a list of known instances where workovers of Tyonek wells requiring killing of the well resulted in substantial losses in productivity. 6. ESTIMATED PRODUCTIVE POTENTIAL OF MGS WELL ~28 Baker well #28 was perforated on March 24, 1994. During initial test production, Unocal was unable to accurately measure the gas rates due to surface equipment limitations. With hydraulic lift being used, the well produced at approximately 800 barrels per day for 11 hours. The well test separator was too small to handle the high gas volume, so the well was shut in. On March 31, the well was routed into the platform's group separation system and the total platform oil shipping rate was monitored. The well began to flow, raising the platform oil rate by 500 to 900 barrels per day before being shut in again on April 1. Flowing tubing pressure was approximately 1300 psig. Once again, equipment limitations, in this case lack of compressor capacity, prevented the gas rate from being accurately assessed. Unocal believes that the well was producing between 2 and 4 MMSCF per day during the test. Shut-in tubing pressure has stabilized at 2050 psig. On April 17, 1994 a pressure gradient survey was run in the tubing to 8300' MD (5178' TVD). The pressure at that depth, 2462 psig, translates to 2481 psi at the top "A" zone perf at 5406' TVD, using the observed wellbore gradient of 0.083 psi/ft (gas). This is equivalent to a reservoir gradient of 0.458 psi/ft, or 8.8 pounds per gallon. Approximately 72 psi of pressure depletion is all that will be necessary for Cook Inlet water (0.444 psi/ft) to be sufficient to kill the well. No accurate estimate of the absolute productive capacity of Baker 28 can be made yet. However, given that the well was being drawn down to 63% of the stable shut-in surface pressure during testing, no more than 1000 to 1800 barrels per day is expected, even under totally uncontrolled flowing conditions. Steep production decline is expected as the local pressure conditions decline to normal field levels. Baker 28 Oompetion Bate: g40,524 0 - 2140' 18 5//8'' OD SURF CSG ':' O- ~8~' 1~ ~/8" OD INT CS(; 0 - 8450' 5.5" OD 2.992" ID'rBG ss 0 - 8462' 3.5" OD 2.992" ID TBG Is 8462 - 8542' 3.5" OD 2.992" ID lB6; 8542 - 8979' 6" OD l'BO cony. guns 8979 - 10483' 4.625" OD I'BO cony, guns O-10565'95,/8" OD 4?,50t/ft PROD KB ELEV:-9999' PBTD: 10502' TB: 10582' 8546- 8554-' PERFS 8560- 8626" PERFS ,8669 - 8680' ERFS 8686 8825' PERFS 8837 - 8888' PERFS 8896 - 891t' PERFS 8924- 8956' PERFS 8945 - 8950' PERFS 8959- 8970' PERB 9054 - 9112' PERF$ 9150:- 9175' PERFS 9200.- 9216' PERFS 9250 9264' PERFS 9287 - 9302' PERFS 9339.- 9486' PERFS 9410 - 9467' PERFS 9482 - 9550~ PERFS 9548 - 9577' PEt~ 96~ - 9652' PERFS 9666 - 9760' PERFS 9779 - 9806' PERFS 10092 -, 10116' PERFS 10155 -10152' PERFS 10544 - 10~52' PERFS 10583 - t0459' PERFS 1045~- 10458' PERFS 10465 - 10475' PERFS ATTACHMENT #2 Unocal Energy Resource. ,vision Unocal Corporation 909 West 9th Avenue, P.O. Box 196247 Anchorage, Alaska 99519-6247 Telephone (907) 276-7600 Facsimile 263-7698 UNOCAL Kevin A. Tabler Land Manager Alaska April 18, 1994 Mr. Russell Douglass Alaska Oil and Gas Conservation Commission 3001 Porcupine Drive Anchorage, Alaska 99501 Dear Mr. Douglass: Re: Baker #28 Well - Application Temporary Waiver [20 AAC 25.265(2)] for Enclosed please find the following supplemental information in support of our application for a temporary waiver dated April 4, 1994: 1. Piping and Instrument Diagram (P&ID); 2. Hazop Summary. We will file the remaining information with you as soon as possible. In the meantime, if you have any questions, please contact me at (907)263-7877 or Mr. Russell Schmidt at (907) 263-7676 for technical information. Enclosure Very truly yours, Elizabeth A.R. Shepherd Project Landman RECEIVED APR 1 8 1994 A~aska 0il & Gas Cons. Commission Anchorage i ill VENT LINE ............... ~.~.: OVERBOARD BYPASS LINE [ij PSE 4~o , {Z~¢h ~'] LC : TEMPORARY X2~2fPOWER FLUlD~OIL - ~' SCRUBBER ,c,I .... SUPPLY '" 'C~~ i, N O NO ~ooo p~b ~4~ J ~~~--- ~. , ......... L~a/ '~ "~ '~-~-- ' NC LC ~ HEADER F~ 1 , , , ,,, , , ,, "-~-"~ ~ BAKER PLATFORH WELL 28 ¢ ............ CBBK INLET, ALASKA ~ CONTRACTOR CONTR. JOB NO. ' UDELHBVEN SERVICES 9305 i i i i i ii i i i i i i i i ii ~ i iii i ~ i i i iii ..... PIPING & INSTR DIAGRAN REFERENCE DRAWINGS .~v..~, ~*~ REVISED .~1~ ~ ~' ~..: APPROVED FOR CONSTRUCTION -*"' ......... WELL ~28 SCRU~3ER p .......... ..... ., ~""" '~ B~4~N¢ ,~.. -- ' .... ' " DA ~ ' i i i i i ii i i i i i ill i i i i i ii i i i i i i i Hazop Summary Platform Baker Well #28 Temporary Separator Installation The designated team met on Monday April 11, 1994, to review the proposed installation of a temporary separator to allow production of baker well #28. A list of the team members follows. All were present. John Amundsen Stewart Brandon Clay Chivers Dwight Johnson Russell Petersen Kriss Wegemer Summary of Proposal Upon completion, Baker well #28 proved to be capable of producing significant rates of both oil and gas. This posed several problems that could not be solved with the existing production equipment configuration on platform Baker. The gas production rates and pressures were such that if well #28 was produced into the oil production unit or test separator, the system was repeatedly shut in on high pressure, unless the well was "pinched back". The oil production rates were high enough that if well #28 was produced into the gas production system, the high pressure dehydration unit was repeatedly shut in on high level of its input scrubber. This situation created two main problems. The first was that the well could not be tested for gas or oil production rates, as the test separator could in no way handle the gas that the well delivered. The second problem was the fact that the well could not be allowed to deliver at its full productivity by any means available. The proposed temporary separator would solve both of these problems. The vessel has the ability to handle both the gas and oil delivered by the well. The vessel is also equipped to be adequately protected from the maximum pressure that well #28 can deliver. Once separated into an oil stream and a gas stream, Baker #28 production can be handled in the same manner as is typical on the platform. The problem of rate testing will also be solved by the fact that the temporary scrubber is equipped with both a gas and a liqUid meter. RECEIVED APR 1 8 1994 Ai~,ska. 0il & Gas Cons. Commission Anchorage Summary of Meetinq Several locked valves were noted. A block valve isolating well #28 from the power oil system will be locked closed. A locked valve will isolate the well's casing annulus from the production header. A locked valve will prevent production from bypassing the temporary scrubber (V-400), FE 401, and PCV 400. For the purpose of introducing a redundancy in isolating Baker #28 from the oil production unit and protecting the 2000 psi mawp production manifold and associated lines, it was recommended that the closing of NSV 335 and NSV 336 should also trigger the closing of NSV 28. NSV 335 and 336 are not shown on the P&ID of the scrubber installation. These control valves are upstream of the two phase and three phase separators and serve to isolate all oil production from platform Baker's oil process. A recommendation was made concerning the installation of some form of gas detection in V-400's relief line, downstream of FE-401 (rupture disk). The recommendation was to investigate the feasibility of such an installation and to install the device if found to be practical. At this point it was recommended that the control logic for the temporary scrubber be such that any general platform shut-in also closes NSV-28. During the discussion of reverse flow, it was noted that oil back-flowing from the production header to V-400 was not checked in any way. Back flow would continue until liquids carried over into the high pressure dehy and resulted in a high level in the dehy scrubber. This would generate a safe shut-in but was identified as avoidable. A recommendation was made to install a check valve in the liquid dump line exiting V-400. This check valve will prevent back-flow into the vessel. A recommendation was also made to consider the installation of a check valve in the gas line exiting V-400. Summary of Recommendations 1. The closing of NSV 335 or NSV 336 should initiate closing of NSV 28 2. Investigate practicality of installing gas detection in V-400 relief line. 3. Configure shut down logic such that any general shut-in closes NSV 28 4. Install check valve in V-400 liquid dump line. 5. Consider installation of check valve in gas flow line exiting V-400 RECEIVED APR I 8 1994 ^~aska Oil & Gas Cons. Commission Anchorage SAFE T CHAR PLatform - Baker We~ ~8 Production Separator NOTES, l) The shut down toglc is to be conFiguped so that any genera~ platform shut-down closes NSV ~) Any s~na[ to close NSV BBS o~ > ~. NSV 336 witt a/so close NSV ~8 ~ 3) PSHL ~8 and PSHL 400 ace set as ~ ~ CoLtows', ~~ High pressure ~hut-in ~t 600 ~~ Low pressure ~hut-ln ot ~00 psi ~ By,, KD~ g~te:4/8/94 PROCESS COMPONENTS ALTERNATE PROTECTION DEVICE iDENTiFiCATiON SAC REF, ALTERNATE DEVICE IDENTIFICATIaN/SERVICE NUMBERS IF APPLICABLE ~ PLC SD Baker ~a8 PSHL ~8 F[ow[ine NSV 335 NSV 336 PSHL 400 Bcker ~8 LSH 400 LC 400 Sepemo~or PC 400 . Hazop Examination Record Baker Well #28 Separator Parameter Guideword Deviation Cause Consequence Safeguards Likelihood Severity/:Rating Recommendation Flow No NSV 428 Closes Lost Production Lact Meter, FE 400 III E 4 FE 401, Operator Rounds LCV 400 Closes High Level V-400, LSH 400, High Press. III D 4 Liquid Carryover into Dehy Scrubber High High Press. Dehy Level Shutdown (PLC), Drain line Bypass PCV 400 Closes High Pressure V-400, PSV 400, PSH 28, III C 4 Gas and Gas Liquids PSE 400, PSH 400 Overboard Block Valve on Oil Same as "NSV 28 Dump Line from V-400 Closed" Closed Block valve on gas Same as "LCV 400 outlet side of scrubber closed" closed Flow More Choke opened or cut High pressure V-400, FE 400, FE 401, Lact II D 4 out High level V-400, high Meter, PSH 400, LSH drawdown (reservoir 400, PSH 28, High damage) Pressure Shutdown /PLC;) NSV 28 Open No new consequences PCV 400 Open High flow, overpress. PSL 400, PSL 28, III D 4 ~ high press, dehy, Iow high press, shutdown r'l-i press. V-400 from high press, dehy ~ (PLC) rtl LCV 400 open Gas to header, Iow level High pressure III C 4 Closing of NSV 335, ~:~ V-400, excess gas to header 336 should also flare close NSV 28 Drawing Title Baker Platform, Piping and Instrument Diagram - Well #28 Scrubber Scribe Kriss We~lemer Line or Vessel V-400 Date 4/15/94 Design Intent To install a vessel to safely separate Baker well ~r28 production into gas and liquid streams Page 1 of 5 Hazop Examination Record Baker Well #28 Separator Parameter Guideword Deviation Cause Consequence Safeguards Likelihood Sevedt)/ Rating Recommendation Flow (cont.) More (cont.) PSV 400 Open High Flow, gas and Current PSV certification IV B 4 gas liquids overboard (11193), line is secured Relief line whipping PSE 400 Ruptures Fasb contents of Visual Inspection IV B 4 Consider gas V-400 overboard detecter in relief line to close NSV 28 on detection All general shut- ins of platform should close NSV 28 Drain Open No new consequences LineJessel rupture Gas release, pos- PSL 28, PSL 400, sible fire pre-startup inspection, hydrotest to 1.5X normal operating pressure Less See "No Flow", no worse than "No Flow" Reverse Production header High level V-400, None II D 4 Install check valve back-flowing into V-400 Liquid carryover into in V-400 liquid dump high press, deh¥ line Gas from high press. No new III E 4 Consider installation ~C7 dehy back-flowing into consequences of check valve in V-400 V-400 gas outlet line Drawing Title Baker Platform, Piping and Instrument Diagram - Well #28 Scrubber Scribe Kd.ss Wegemer Line or Vessel V-400 Date 4/15/g4 Design Intent To install a vessel to safely separate Baker well #28 production into gas and liquid streams Page 2 of 5 Hazop Examination Record Baker Well #28 Separator Parameter Guideword Deviation Cause Consequence Safeguards Likelihood Severity Ratin~] Recommendation Pressure High Choke opened of cut No new out consequences NSV 28 open No new consequences PCV 400 open No new consequences LCV 400 open No new -consequences PSV 400 open No new consequences Low Same as line/vessel rupture Drawing Title Baker Platform, Piping and Instrument Diagram - Well #28 Scrubber Scribe Kdss We~lemer Line or Vessel V-400 Date 4/15/94 Design Intent To install a vessel to safely separate Baker well #28 production into gas and liquid streams Page 3 of 5 Well #28 Se Hazop Examination Record High level in high Parameter Guideword Deviation Cause Consequence Safeguards Likelihood Severity Ratin~ Recommendation Level ~ High LCV 400 closed, High level V-400, LSH 400, high level III C 4 LC 400 failure High level in high shut-in from level press, dehy sensor in dehy scrubber (PLC) Low LC 400 failure, High flow, Iow press. PSL 400, PSL 28, III C 4 Closing of NSV 335, LCV 400 open V-400, high press, high pressure shut-in 336 should also production header, signal from production close NSV 28 excess gas to flare header (PLC) Drawing Title Baker Platform, Piping and Instrument Diagram - Well #28 Scrubber Line or Vessel V-400 Design Intent To install a vessel to safely separate Baker well #28 production into gas and liquid streams Scribe Kdss Wegemer Date 4/15/94 Page 4 of 5 Hazop Examination Record Baker Well #28 Separator Parameter Guideword Deviation Cause Consequence Safeguards Likelihood Severit~t Ratin[I; Recommendation, Temp. Hi/Fire LineNessel rupture Potential structural Personell training, IV B 4 failure fire fighting equipment Lo Freezing across choke Same as "NSV 28 closed" Freezing across PCV Same as "PCV 400 400 closed" = · Drawing Title Baker Platform, Piping and Instrument Diagram - Well #28 Scrubber Line or Vessel V-400 Design Intent To install a vessel to safely separate Baker well #28 production into gas and liquid streams Scribe Kriss Wegemer Date 4/15/g4 Page 5 of 5 Notice of Public Hearing STATE OF ALASKA Alaska Oil and Gas Conservation Commission Re: The application of Union Oil Company of California (Unocal) as operator of the Baker Platform, requesting a temporary waiver of 20 AAC 25.265(2) to allow production of MGS 17595 No. 28. Unocal by correspondence dated April 4, 1994 has requested a temporary waiver to the provisions of 20AAC 25.265(2) requiring an automatic subsurface safety valve (SSSV) capable of shutting off uncontrolled flow in MGS 17595 Well No. 28. Unocal intends to install a SSSV, however, no packer exists in the well, so total shut off of flow from the tubing-casing annulus would not be possible in the unlikely event of catastrophic failure. The waiver is necessary to avoid economic waste and maximize production efficiency and at the same time allow the well to be produced in a safe and prudent manner. A person who may be harmed if the requested order is issued may file a written protest prior to 4:00 pm April 21, 1994 with the Alaska Oil and Gas Conservation Commission, 3001 Porcupine Drive, Anchorage, Alaska 99501, and request a hearing on the matter. If the protest is timely filed and raises a substantial and material issue crucial to the Commission's determination, a hearing on the matter will be held at the above address at 9:00 am on May 9, 1994 in conformance with 20 AAC 25.540. If a hearing is to be held, interested parties may confirm this by calling the Commission's office, (907) 279-1433, after April 21, 1994. If no protest is filed, the Commission will consider the issuance of the order without a Russell A. Douglass Commissioner Alaska Oil and Gas Conservation Commission Published April 6, 1994 STOF0330 A0-08-5770 $61.75 AFFIDAVIT OF PUBLICATION STATE OF ALASKA ) THIRD JUDICIAL DISTRICT ) SS. Eva M Kaufmann being first duly sworn on oath deposes and says that she is the Advertising Representative of the Anchorage Daily News, a daily newspaper. That said newspaper has been approved by the Third Judicial Court, Anchorage, Alaska, and it now and has been published in the English language continually as a daily newspaper in Anchorage, Alaska, and it is now and during all said time was printed in an office maintained at the aforesaid place of publication of said newspaper. That the annexed is a copy of an advertisement as it was published in regular issues (and not in supplemental form) of said newspaper on: Apr/7 6, ,1994 and that such newspaper was regularly distributed to its subscribers during all of said period. That the full amount of the fee charged for the foregoing publication is not in excess of the rate charged private individuals. signed ~'C.~~~~-~~' Eva M. Kaufmann I"') Classified Advertising R'e~. 257-4296 Notice of Public Hearing , STATE OF ALASKA , AlaSka Oil'and ' Gas Conservation Commission Re: The:aPPlication of' union Oil ComPany of California (Unocal)' as,: 'operator, of the Baker Plafform~ ~luestlng' a ~ temporary 'waiver, of 20 AAC~ 2S.2~(t)'ffo allow productioh of, MGS'17~5 No, 20.'" Unbeat. by correspondence. dated .APril, 4,','l~94.'.has re-i questS-a:::femp0rary waiver to' the' Oi;o%iSion'$ .'of 20 "AC 25 265(2) requlri.~ an automat; ic sUbsurfaCe'safetY'valye' (SSSV') C~ipal~l~"'0f shitting off .. uncontro ledflw in MGS 17595 '. Well NO.; 2IL !'.'". ' . Unocalqntends to install a SSSV, ho~veger, no 'packer ex- Isis in the well, so tota Shutoff of fli~v ~fl'om, ~he,tUbing-caslng annoloS'~'~boldl la0t'.be,~o~lble I n .the': Un'likelY, e~nt ' 0f cata- strOPN'c failure. 'T,'h.~ Waiver is "necessary ,'tO'.::avold e~onomlc 'waSte "'and, ,rPaxlmlze,'~ i3ro~uc- ~ , lion efflc~enc~t' and at the ~ame/ · t meail°wtfie wail'robe pro, ',, duced..;~n',,,;~'~::,~afe and .~prudent ' manneL '.' (...::'.': i'~':'?: ". ':..: :'/' ~, A person WllO,,'may.; be ~arm.: ed if..tile.req~st~d ...oraer. issu~d.ma~.::fl ~':.a.:wrl~en Pro.. '.te%t'pflo'i" t0'.4::00 :P~: A'P'ril 21, ' l~14.',withi:'the', "AlaSka,,,OH, and Gas.¢0fis~rVafro~' commission, 30ol. porCUpine Drive, Anchor- age, Alaska. 995ol, and.. reqUest a hearing on the maffer. If the protest is timely filed and raises a substaatlal and mate- ' rial Iss~u~.~ccucia. to :the Com- mis~bh ~' l'det~rmlna'it:bn, 'a hearing on. the matter will be held at .the .above address at 9:00. am :on May 9, 1994 in conformance wlth 20 AAC . 25.540. If a hearing is to be ~. held, interested, par!.ies may confirm thls' by calling the Commission's office; (907) 279-1433, after'April 21, 1994. If "' no protest '.Is filed, the Com- mission will ~:onsider the issu- ante of the Order wifhout a hearlflg. /s/Russell A. Douglass Commissioner Alaska Oil a~ld . Gas Conservation Commi.ssion Pub iSh/.:~Pt,,;i .::6; 1994 ....L..._.[ Subscribed and sworn to before me this ..~.... day of ..... ...(~....~. ...... , 1994 Notary Public in and for the State of Alaska. Third Division Anchorage, Alaska MY COMMISION EXPIRES: ~4'~ Commission Expires: ....... .......... a 9 ...... Unocal Energy Resourc~ !vision Unocal Corporation 909 West 9th Avenue, P.O. Box 196247 Anchorage, Alaska 99519-6247 Telephone (907) 276-7600 Facsimile 263-7698 UNOr. Kevin A. Tabler Land Manager Alaska April 4, 1994 Mr. Russ Douglass Alaska Oil & Gas Conservation Commission 3001 Porcupine Drive Anchorage, Alaska 99501 Dear Mr. Douglass: Union Oil Company of California (Unocal), as operator of the Baker Platform, requests that the Alaska Oil and Gas Conservation Commission (AOGCC) grant a temporary waiver of 20 AAC 25.265 (2), requiring an automatic subsurface safety valve (SSSV) capable of shutting off uncontrolled flow in MGS 17595 Well No. 28. Unocal intends to install an SSSV, however, no packer exists in the well, so total shut off of flow from the tubing-casing annulus would not be possible in the unlikely event of failure of the surface safety systems during an even more unlikely catastrophy. This waiver is necessary to avoid economic waste and maximize production efficiency and at the same time allow the well to be produced in a safe and prudent manner. Background When Unocal applied for a permit to drill the referenced well, it was anticipated that all oil-bearing zones encountered and subsequently completed would not be capable of unassisted flow to the surface These zones included the "A" "BCD" and "EFG" pools While all of these zones were capable of flowing at the time of discovery in 1964, pressure depletion occurred rapidly with production. All recently drilled new wells and recompletions have not had sufficient pressure to flow to the surface unassisted by artificial lift. Baker 28 has apparently been completed in at least one oil zone with sufficient pressure and associated gas to flow to surface. This unexpected good fortune should mean higher than anticipated oil and gas production rates and ultimate recovery from the well. RECEIVED APR - 5 1994 Aiaska 0ii & Gas Cons. Commission Anchorage AOGCC April 4, 1994: Page 2 Production of this zone is expected to result in rapid pressure decline, as seen in the rest of the field, and will soon render the well incapable of unassisted flow and require use of a pump to produce fluid. At that time no packer would be required. In fact, the presence of a packer in a pumping well would have a detrimental effect on the production capacity and economic life of the well. Safety Unocal believes that Baker #28 can be produced in a safe, prudent manner without a packer. A combination of surface and subsurface safety equipment will virtually eliminate the possibility of uncontrolled flow of fluid to the surface. During the short time the well is expected to flow, the level of safety is felt to be approximately the same with or without a packer. Unocal will install subsurface safety equipment on Baker ~28. The well is completed with two parallel tubing strings attached to a hydraulic pump receptacle, or "cavity." The safety equipment will consist of an assembly that seats in the pump cavity and is ported to allow fluid to flow through the cavity and into one of the parallel tubing strings to the surface. Hydraulic pressure applied to the other tubing string will keep a sub-surface safety valve in the open position. The tubing string in this case will serve the same function as the hydraulic control line in a more typical SSSV installation. As with any surface-operated sub-surface safety valve, loss of line pressure for any reason will close the valve and shut the well in. This equipment satisfies the requirement for surface-controlled sub-surface safety equipment. Additionally, we will install automatic surface shut-in valves and separation and testing equipment equipped with high and low pressure and level shut-downs. Standard Hi-Low pressure shut-in valves will be installed at the wellhead on both the tubing and annulus. This combination of equipment will ensure safety in the unlikely event of any mishap that occurs on the surface, from the wellhead through the production equipment, including flowlines, pressure vessels, tanks, and pumps. A packer would only provide additional protection in the event of simultaneous failure of the surface safety systems attached to the annulus and a leak or rupture in the production system; or in case of failure of the casing below the wellhead. This is highly unlikely on a continuously manned, properly lighted and maintained offshore facility such as Platform Baker. No such event is known to have occurred in 28 years of operations at Baker. The casing in the R£C[IV£D APP, - 5 '1994 git & Gas Cons. Commissioa Anchorage AOGCC April 4, 1994: Page 3 well is brand new, and was inspected for defects prior to being run into the well. The 9 and 5/8" casing was tested to 3500 psi surface pressure at the time of completion. Thus no possibility of corrosion or other factors that would lessen the integrity of the casing exists, especially considering the expected brief duration of flowing operations. While Unocal will not rely on it, an additional natural safety factor exists since the reservoir pressure is thought to be low enough that, in the event of a catastrophy, Cook Inlet water rushing into the well would be sufficiently dense to kill it, thereby minimizing the loss of hydrocarbons to the environment. Unocal intends to measure the bottom-hole pressure in the well within seven days to confirm this. The safety margin will increase as the well is produced until it is incapable of unassisted flow. Flow up the tubing-casing annulus requires more reservoir pressure than flow up tubing, so the packer will actually become redundant even before the well ceases to flow. Unocal will monitor the pressure decline in the well by taking frequent pressure measurements during the term of the waiver. Even if the well is still capable of flowing, six months of production and pressure data should be sufficient to determine the length of any extension of the waiver, if necessary. Justification Several reasons for waiving the packer requirement exist. Firstly, the Tyonek "A" and "BCD" pools are comprised of reservoirs that are extremely sensitive to damage by water-based kill fluids. Several wells in the past have been virtually sealed off by damage induced during workover operations. No kill fluid has been found that is not damaging to the formation. A packer can not be installed without killing the well and pulling the existing completion. Therefore, a near certainty exists that a workover will permanently impair productivity and reduce recovery of oil and gas from the well. Also, a packer will negatively affect artificial lift since it will force all gas in the well to be produced through the hydraulic pump and the tubing, instead of being vented up the casing, as the well is currently designed to do. Pump efficiency is severely hampered by gas compression in the pump. With a packer in the well, production rates will be restricted once the well ceases to flow on its own, reducing ultimate oil and gas recovery from Baker #28 and Middle Ground Shoal Field. RECEIVED APR - 5 1994 ~,~aska Oil & Gas Cons. CommissioR Anchorage AOGCC April 4, 1994: Page 4 Finally, since the well is expected to experience rapid pressure decline, the flowing condition should not last long. The unnecessary expense and risk associated with a workover would be avoided by carefully monitored production and depletion of the reservoir. Unocal intends to provide supplemental data on proposed safety equipment, reservoir pressures, pressure decline, formation damage and artificial lift considerations to the Commission within 10 days. Please direct any technical questions regarding this request to Kurt Bair, reservoir engineer at (907) 263-7646. Thank you for your assistance. ~'ncere~l~./~ evin A. Tabler RECEIVED APR -5 1994 A,~ask~ Oil & Gas Cons. Commission Anchorage ATFACHMENT #4 Tyonek Workovers --Examples of Lost Productivity Well Date Operation Before (bopd) After (bopd) Baker #5 Jan '67 Add perfs 450 (BCD) 200 Baker #6 Nov '85 (BCD) Sqz. & add perfs 200 8O Baker # 17 June '92 Shift Sleeve 180 lost annular brine to formation 3O Anna #4* Mar '84 Reperf attempt 303 207 Anna #9 Jan '74 Replace Pump 352 214 Oct '83 Replace BHA 670 Anna 15 june '74 Replace BHA 768 575 633 Anna 23RD* Oct. '82 Replace BHA 550 200 Anna 24 Oct '82 Replace BHA 304 164 Bruce #3 Oct '81 Replace BHA 515 370 Bruce #34 Nov '82 Replace BHA 120 6O * - diesel as well control, all other examples are brine.