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Home My WebLink AboutCO 236Conservation 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. ~-~ ~_2- Conservation Order Category Identifier Organizing RESOAN [] Color items: [] Grayscale items: [] Poor Quality Originals: [] Other: NOTES: DIGITAL DATA [] Diskettes, No. [] Other, No/Type OVERSIZED (Scannable with large plotter/scanner) [] Maps: [] Other items OVERSIZED (Not suitable for plotter/scanner, may work with 'log' scanner) [] Logs of various kinds [] Other BY: ARIA Scanning Preparation Production Scanning Stage I PAGE COUNT FROM SCANNED DOCUMENT: ~ PAGE COUNT MATCHES NUMBER IN SCANNING PREPARATION: ~ YES NO 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 QUALITY, GRAYSCALE OR COLOR IMAGES) General Notes or Comments about this Document: 5/21/03 ConservOrdCvrPg.wpd STATE OF ALASKA ALASKA OIL AND GAS CONSERVATION COMMISSION 3001 Porcupine Drive Anchorage, Alaska 99501-3192 Re: THE APPLICATION OF SHELL ) WESTERN E & P INC and THE ) AMOCO PRODUCTION COMPANY ) for a revision of Rule 7 ) Conservation Order No. 44 ) which specifies field rules ) for the Middle Ground Shoal ) Field. ) Conservation Order No. 236 Middle Ground Shoal Field MGS Oil Pools A, B, C, D, E, F, & G June 2, 1988 IT APPEARING THAT: · Shell Western E & P Inc. submitted the reference application dated May 11, 1988 to allow changes to the surface casing setting depth. · Notice of opportunity for public hearings on this request was published in the Anchorage Daily News on May 4, 1988 pursuant to 20 AAC 25.540. 3.' No protest to the application was filed. FINDINGS: 1. · · When Rule 7 was established in 1967, wells were drilled from surface casing depth to total depth and then cased. Most wells drilled since 1976 have been completed by cementing an intermediate casing string above the productive zone. Ail formations encountered between the surface casing shoe and the top of the productive zone are normally pressured. 4. Competent formations exist as shallow as 800'TVD. Conservation Order No. 236 June 2, 1988 Page 2 CONCLUSIONS: Safety would not be reduced by setting surface casing as shallow as 1000'TVD when an intermediate string is set above the producing interval. NOW, THEREFORE, IT IS ORDERED THAT Rule 7 of Conservation Order No. 44 is repealed and is reenacted to read: Surface casing must be set and cemented to a depth of at least 1600 feet TVD if no intermediate casing string will be set. If an intermediate casing string is set between 4000' TVD and the shallowest abnormally pressed waterflood zone, surface casing must be set and cemented to a depth of at least 1000 feet TVD. In either case, sufficient cement must be used to circulate to the surface. DONE at Anchorage, Alaska and dated June 2, 1988. C. V. Chatt-'~r~'~/sqConservatzon Commis Alaska Oil and ' s ion Lonnie C. Sm~th,~Commissioner Alaska Oil a W. W. Barnwell, Commissioner Alaska Oil and Gas Conservation Commission ALASKA OIL AND GAS CONSERVATION COMMISSION ,,~?~ STEVE CQWPER, GOVERNQR 3001 PORCUPINE DRIVE ANCHORAGE, ALASKA 99501-3192 PHONE: (907) 279-1433 TELECOPY NO: (907) 276-7542 January 4, 1989 Dear Subscriber: The Commission inadvertently issued two Conservation Orders under the number 236. The first one was issued to Shell Western E & P Inc. and Amoco Production Company and will remain as issued. The second one was issued to Unocal on July 29, 1988 and shall be redesignated henceforth as C.O. No. 93A. Please make the necessary corrections to your files. We regret any inconvenience. Very truly yours, Lonn±e C. Sm±th Comm±ss±oner dlf: RAD / CO93A Notice of Public Hearing STATE OF ALASKA Alaska Oil and Gas Conservation Commission Re: The application of SHELL WESTERN E & P INC. (SWEPI) to amend Rule 7 of Conservation Order No. 44 Shell Western E & P Inc., by letter dated March 11, 1988, has requested an amendment to Rule 7 of Conservation Order No. 44. The amendment would allow changes to the surface casing setting depth. A person who may be harmed if the requested order is issued may file a written protest prior to May 20, 1988 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 materi- al issue crucial to the Commission's determination, a hearing on the matter will be held at the above address at 9:00 a.m. on June 7, 1988 in conformance with 20 AAC 25.540. If a hearing is to be held, interested parties may confirm this by calling the Com- mission's office, (907) 279-1433, after May 20, 1988. If no proper protest is filed, the Commission will consider the issu- ance of the order without a hearing. W. W. Barnwell Commis s ioner Published May 4, 1988 ~,' .... ..~'. . . .~ ~ "'~.. STATE OF A~SKA'.~'.'~- '{~ to' ~mend Rule 7 ~.COn~-~ ~'~" tl~ Order ~. ~ ,' .... '~. :':,.. · ~'. ~o. ~. The ~mend~ent would '.~,~.~sing ~fllng d~th.' . r.,,.' ~''; A ~r~ who mey'~ ~erm~., :.'..' 011 Ind ~tl (~tlon ~. ~n~hor~, ~l~sk~ ~1~ end' ,. filed, and ~al~S'a, Sub~antltl.~ ;~. ~ and materlal'~lSs~ crucial tot the ~ Comml~slonfs [.': tlon, a hea~l,~.~:, the mafle~ ~ will ~ held.~Mtt~ e~ve , ~'. dress at '.". I~,. In c~mance 'With .~.':.' held, ' Intere~t~ ~' confirm thl~',. ~" ~'.:.~ 279-1~, after .~ay ~, 19ffi. If .~.: no pr~r prote~ '" Comml~l~ wIII.c~slder ~ ' I~uance ~ t~ '. [.,. ~arlng. '. . . , , :, , , ';'~IIMICI. M Public ' ,"~' amend' Rule I ~, C~M~a' , :,fl~Ord~ N°.'u. '~"' :.:.:.s~,..w.t~n ,E &, inc., . ii.er d~J~ ~arch 11~, 19M~ has ,',.','r' uest~ an, amendment' to ' ,,,,',~e 7 M.'C~M~atl°n Or'ri ,' ~,~:No. ~. The amendment ~uld ',:~,jll~' chan~ to the"sudace . ,, -~slng Mfflng de~h~ ,:~',i~ay file':a W iflen prote~ prlorJ ,:;;,f~ ~j~ ,~, ~, W'Wltb"the ';~!!~: J~ Gas, :~M~atlon Corn :.~ ~nc~a~~ , ~.,.t~e.. ~er flon, ~ hel . . ~re~ af I confirm t~l~.~~ ~) _ .. I · 2~1~, afl · ~ pr~r pr~tat 'It (i1~, the commi~l~ ':Jlll' .'c~sidet t~'l · i.uance ~ t~ 'r~r' wlfho~.:~ ,,,,,.... .... PUb: ~ay 4'~, 19~ :' .... u':.~ ..;.';' "~'."'?~ f. ? .,..; · .,.:' F STATE Of ALASKA ADVERTISING ORDER 8605 Anc133rage Daily News P. O. Box 149001 And3orage, Alaska 99514-9001 Alaska Oil & Gas Cc~mervation Com~ssion 3001 Porcupine Drive - Anchorage, AK 99501 ADVERTISING ORDER NO. A0- 08-55 AGENCY CONTACT I DATE OF A.O. Pat Oldenbtn:g M~y 3, 1988 PHONE / (907) 279-1433I '-' DATES ADVERTISEMENT REQUIRED: May 4, 1988 SPECIAL INSTRUCTIONS: AFFIDAVIT OF PUBLICATION UNITED STATES OF AMERICA STATE OFAlaska ss Third DIVISION. BEFORE ME, THE UNDERSIGNED, A NOTARY PUBLIC THIS DAY PERSONALLY APPEARED Sheila C. Allot WHO, BEING FIRST DULY SWORN, ACCORDING TO LAW, SAYS THAT HE/SHE IS THE Legal Ad. Asst. OF PUBLISHED AT Anchorage Third AND STATE OFAlaska Daily News IN SAID DIVISION AND THAT THE ADVERTISEMENT, OF WHICH THE ANNEXED IS A TRUE COPY, WAS PUBLISHED IN SAID PUBLICATION ON THE 4th DAY OF May 19 88, AND THEREAFTER FOR~ CONSECUTIVE DAYS, THE LAST PUBLICATION APPEARING ON THE ~ DAY OF 19__, AND THAT THE RATE CHARGED THEREON IS NOT IN EXCESS OF THE RATE CHARGED,.PRIVATE INDIVIDUALS. SUBSCRIBED AND SWORN TO BEFORE ME THIS4 DAY OF Maq . 1988. NOTARY PUBLIC F~)R STATE-~)F Alaska MY COMMISSION EXPIRES Jul q 9 , 1990. REMINDER-- INVOICE MUST BE IN TRIPLICATE AND MUST REFERENCE THE ADVERTISING ORDER NUMBER.' A CERTIFIED COPY OF THIS AFFIDAVIT OF PUBLICATION MUST BE SUBMITTED WITH THE INVOICE. ATTACH PROOF OF PUBLICATION HERE. ;'"' ;'t' STATE; OF ALASKA: .~,~,~,~,~r-; .... Alaska OII end Gas "' ,, ~;:;~:,., ~atl~ ~mmlul~ ..,, ~.;. ,,,,, . , . :,~ ~ . , , 4~yW~ E &,P ~.,'(SWEPO ~" :,~. am~ Rule ~ ~ ~a-. ,,~ , , . ~. ,t..., ,~ ~ >;;~?,, ·.; leff~ dat~ ~arc, 11,'1~, '.~, ~ an amendm~t · ~..'Ro~ 7 ~ C~atl~ ~der ,' No. ~ T~ amendme~ ~ld :." ~11~ chln~ lo t~ .~a, ~:~: ~ ~y ~, I~ with t~ A~s~ .;'-;.,OII ~ 6as Cm~aflm Corn-' ;: ".ml,l~, ~1 P~cupl~ Drive,, :.*"' rN~ ~ Marl~ ~. ~ mat- '::'- fUN, aM :.~ ? fl~, a ~1~{~ ~ 'ma~, ' .~?' will ~ hel~;t~..~l ~.j.*.: drm at 9:~ ~ .~ ~ld,' I~,:~1~,' may" confirm tbl~', b~,,~lllng' ,'. ~I~, ~'~y ~, 1~ If~ ~ '~,. ~mml,l~ ~11.~1~ '~ '. ~ ~ ' ~ I/'. t .., .~ )2-901 (Rev. 6-85) PUBLISHER April 26, 1988 ~laska Oil & Gas Conservation Commission 3001 Porcupine Drive Anchorage, Alaska 99501 Attention: Mr. C. V. Chatterton File: MAG-O59-986.AOGCC Gentlemen: Amoco Production Company P. 0. Box 100779 Anchorage, Alaska 99510 Proposed Change to Conservation Order No. 44, Rule 7 Amoco Production Company has reviewed the change to Conservation Order No. 44, Rule 7 proposed by Shell Western E&P, Inc. (SWEPI) as set forth in their March 11, 1988 correspondence to you (copy attached). Please be advised that Amoco is in agreement with this change as proposed. Very truly yours, M. A. Golas District Operations Supervisor Attachment cc: B. S. Mamerow - Denver D. R. Weekley - Denver J. D. Hamrick- Denver M. L. Woodson - SWEPI KWU/s 1 s March 14, 1988 Mr. C. V. Chatterton Alaska Oil and Gas Conservation Commission 3001 Porcupine Drive Anchorage, Alaska 99501 Shell Western E&P Inc. 601 West Fifth Avenue · Suite ~ Anchor age, Al as ka 99~.~!501 '~l'~-~'-"' '-" "~.¥. ' iRES EN~ Dear Mr. Chatterton' SUBJECT' MEETING TO DISCUSS PROPOSED CHANGE IN MIDDLE GROUND SHOAL FIELD CONSERVATION ORDER #44, RULE 7 As discussed with Commissioner Lonnie Smith, a meeting has been scheduled for Friday, March 18, 1988, at 9'00 a.m. to present Shell Western's proposal for changing Conservation Order #44, Rule 7. Enclosed for your information is an outline of the discussion. We appreciate this opportunity to meet with you. Very truly yours, Division Operations Manager Alaska Division MLW/SBB/kt Enclosure MLW4/031488b SUBJECT: Proposed change in MGS surface casing depth field rule TOPICS OF DISCUSSION' Present MGS surface casing field rule (established 7/19/67) Post 1974 MGS wells all have protective casing strings Weak zone between 2600 and 3000' TVD Current leak off test information Casing design safety factors Savings of $15 to 30M per well, without sacrificing safety Proposed plan to determine optimum surface casing depth March 11, 1988 Shell Western E&P Inc. 601 West Fifth Avenue · Suite 810 Anchorage, Alaska 99501 Alaska Oil & Gas Conservation Commission 3001 Porcupine Drive Anchorage, Alaska 99501 Gentlemen' SUBJECT- PROPOSED CHANGE TO CONSERVATION ORDER #44, RULE 7 Shell Western E & P Inc. (SWEPI) proposes an update to Conservation Order #44, Rule 7 (dated 7/19/67) which pertains to Middle Ground Shoal. The rule presently reads' Surface casing must be set and cemented to a depth of at least 1600 feet. Sufficient cement must be used to circulate to the surface. SWEPI proposes the amended rule to read' Surface casing must be set and cemented to a ~~VF~' depth of at least 1600 feet TVD IF NO INTER- INTERMEDIATE CASING STRI.NG IS SET BETWEEN 4000' MA.~I i TVD AND THE SHALLOWEST ABNORMALLY PRESSURED C ...... ~ATERFLOOD ZONE, SURFACE CASING MUST BE SET AND ommlssm Alaska Oi~&GasCons. ~EMENTED TO A DEPTH OF AT LEAST 1000 FEET TVD. Anchorage IN EITHER CASE, sufficient cement must be used to circulate to the surface. .~ The present Rule was established approximately two years after the first production well was drilled. At the time, all wells were drilled from surface casing to total depth and then cased. Thus, SWEP,I surmises Rule 7 was predicated under this type of well plan. Since 7/19/67, conditions in Middle Ground Shoal have changed and more information has been obtained. All SWEPI's Middle Ground Shoal Hemlock formation wells drilled since 1976 have intermediate casing strings. The intermediate casing strings are required to safely control formation pressures induced by the waterflood program. All formations between surface and intermediate casing are normal (virgin) pressured. All abnormally pressured zones are encountered after intermediate casing is set. Thus, for practical purposes, the intermediate casing can be considered a deep surface casing string. See the attached pre and post waterflood program casing well designs. The weak (lost circulation) zone off our Platforms is apparently between 2600 and 3000' TVD. Circulation has been lost on 15 occasions below surface casing. A mud weight of 9.9 to 10.5 ppg was being used 87% of the VEU7/030988 Page 2 time circulation was lost. On the other hand, at least 18 times a mud weight of 9.9 to 10.5 ppg has been used to drill surface hole and circulation has never been lost prior to running casing. The point being, the weak zone in Middle Ground Shoal has been considerably below the surface casing shoe, regardless of where surface casing has been set (surface casing has been set as shallow as 692' TVD when intermediate casing was run). On the occasions circulation has been lost, past records of the bit depth, mode of operation, interval where lost circulation pills were spotted, and the depth the drill string was pulled to regain circulation all indicate the weak zone is between 2600 and 3000' TVD. Current leak off test data indicates an 11.0 ppg equivalent mud weight is obtainable at 800' TVD. An 11.0 ppg leak off is 0.5 to 1.1 ppg heavier than leak off in the weak zone between 2600 and 3000' TVD. See the attached formation leak off gradient plot. Under the proposed plan, the casing design safety factor in collapse is approximately 1-3/4 and the burst safety factor over 3. SWEPI's objective (in wells with intermediate casing) is to set surface casing at the deeper of: 1) the end of the directional angle build section, 2) an 11.0 ppg fracture gradient at the surface casing shoe, or 3) 1000' TVD. Setting surface casing shallower represents a savings of $50 per foot, a savings over $30,000 on some wells. The savings is predominately in cement and casing material costs. This savings is obtained without sacrificing the safety or integrity of the operation or wellbore in any manner. In summary, SWEPI is convinced surface casing can be set as shallow as 1000' TVD on wells that incorporate an intermediate casing string without sacrificing safety or increasing risks. The entire industry benefits from safer, more efficient well programs. SWEPI believes the proposal presented at the beginning of this letter, backed by the data and experience of 55 Middle Ground Shoal wells, will be a benefit to the industry. SWEPI looks forward to your response. If you have any questions or desire more data, please call me at 263-9625 or Ed Urger at 263-9634. Sincerely, Division Operations Manager MLW/VEU/ljm cc: C..M. Kidwell W. F. Simpson S. B. Brown Reading File Houston Production File VEU7/030988 PRE WATERFLOOD CASING PROGRAM POST WATERFLOOD CASING PROGRAM rr Z MIDDLE GROUND SHq FORMATION LEAK OFF GRADIENT 0 0 0 ---t-- '., -? ......... ~,---~ ..... ~-k.--'~ .... 1-~ ...... ~--'r i--~ .... i'''~ ...... T ...... I- i ~ ~'''~ ] ~-'-] 'I-('PROPOSED MINIMUM.SURFACE 9ASING DEPTH ! ' '~ ~ '~ ~1 ........ ~ . ..... ~ i ..... '-~~ t ~ , -'~', ....... i-- -~ "--~, ! ,, , ~ .,.. , -i ' X't ..... ~ ~---T-''~ .... .... ~'"~ .... ~'--~ ......... i' ~ I I'" -; ~--1. ....... 1 r'--~--~-'-r--~ ~, ~w ........... ] ~ ] .... ~-'t-~ : ....... ~ ~~ r .... ~ : ~ : ~ -~ ~--~ ..... ~'--i~i .... %-'~--~--~ i-'~'-;'- :---~----H--'---:-~--% i ~~--~-- - -~ .... 1 ..... ' -'-1 ........ ~ ...... ~'--~-" x~ ........ ~ ..... ~--r '--;--' ~r--~ , ~ I , ~ I ........ ~._ !_..k ..... ~_._~ ....... t ....... . ..... ,__.~_.: .... ~. 1._~_,_, , _,_._,~_ , ~,~ I ~!1~I/I/1~ I i I I ~ , ; ~ i 1 , I , ~ , i ~ '. , .... ~ 7~ 7/~/~ --; ........ -- .......... - ....... ' ......... ~ ..... ~ ...... t--i ......... ~ ........ ~ ..... 1 ........ l-~*--~ .... 1-~~uN~-l' ~ -;~, ; , . t t , .......................................... , ............ ~.~__,_~ ............ PROPOSED MINIMUM PROTECTIVE. ~--N~ ...... ~ i~-fl ...... CASING DEPTH I I I ~ ~, I ~ 1 i i ~ ~ l .... q .... ~--"] ..... ~ ..... ~ .............. 1 .... t ....... ~---~ ...... ' ........... ~ ~ .... I i 2 , ' I ' / ~ --t ......... ~---~ ...... ~ ....... .... ~ .......................... ~ ..... ~-'- i~ ......... ] ........ :~, i t i I '~X~.' ..... _, ....... I ........................ ......... ..... ....................... ' ..... .....: I ...... [~'~'~! : ............................... !"e , ......... i- IX---I .......... I ...... i ...... 1 .... ~ ...... 1 1 1 I 1 FORMATION LEAK OFF GRADIENT (equivalent mud weight in ppg)