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Home My WebLink AboutCO 078Conservation 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. ~)7_~ Conservation Order Category Identifier Organizing RESCAN [] Color items: [] Grayscale items: [] Poor Quality Originals: [] Other: NOTES: DIGITAL DATA [] Diskettes, No. [] Other, No/Type OVERSIZED (Scannable with large plo~e.~/scanner) .~~Maps: J Other items OVERSIZED (Not suitable for plotter/scanner, may work with 'log' scanner) [] Logs of various kinds [] Other BY: ROBIN Scanning Preparation BY: ROBIN Production Scanning Isl Stage PAGE COUNT FROM SCANNED DOCUMENT: ..~ I 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 A'I-rENTION 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 DEPARTMENT OF NATURAL RESOURCES DIVISION OF OIL AND GAS Alaska Oil and Gas Conservation Committee 3001 Porcupine Drive Anchorage, A1 aska 99504 Re: THE APPLICATION OF ATLANTIC RICHFIELD COMPANY for an exception to Title ll, Alaska Administrative Code, Section 2056(a). ) Conservation Order No. 78 ) Prudhoe Bay Field ) Drill Site No. 1 Well No. 32-8-10-15 ) August 14, 1969 IT APPEARING THAT: 1. By letter dated July 22, 1969 and amended July 31, 1969 the Atlantic Richfield Company requested an exception to Title ll, Alaska Administrative Code, Section 2056(a) for the referenced well. 2. The request was to permit installation of specially designed slip joint casing to be set in the permafrost section without circulating cement on the permafrost and surface strings of casing. 3. Notice of the hearing on the request was published in the Anchorage Daily News on August 2, 1969 pursuant to Title ll, Alaska Administrative Code, Section 2009. 4. A public hearing was held on August 13, 1969. Testimony was presented by the Atlantic Richfield Company and there were no protests. AND IT FURTHER APPEARING THaT a study of the theoretical effect of producing oil from wells drilled through the permafrost indicated that subsidence through thawing may possibly occur and that drag of the subsiding soils could cause the failure of casing in a well conventionally cased and cemented in accordance with Title ll, Alaska Administrative Code, Sect~on 2056(a). AND IT FURTHER APPEARING THAT the installation of specially designed slip joints in the permafrost casing string may enable that string to withstand the forces of subsidence if it is not cemented through the zone of subsidence'. AND IT FURTHER APPEARING THAT the use of a specially designed wellhead will enable the permafrost Casing to move relative to the surface casing and will allow the surface casing to carry the load of the inner casing and tubing strings. CONSERVATION ORDER NO. 78 Page 2 August 4, 1969 AND IT FURTHER APPEARING THAT an exception to Title ll, Alaska Administrative Code, Section 2056(a) for the referenced well should be granted to minimize the possibility of casing failure. NOW, THEREFORE, IT IS ORDERED THAT the Atlantic Richfield Company be permitted to install slip joints in the permafrost casing without cementing through the expected zone of subsidence, to fill the annulus between the surface and .permafrost casing strings only u.p to the expected zone of subsidence and to use specially designed wellhead equipment in the Drill Site No. l, 32-8-10-15 well for protection against possible subsidence. DONE at Anchorage, Alaska, and dated August 14, 1969. Thomas R.' Marjh'all, Jr.' ExeCUt'~V'e Secretary Alaska Oil and Gas Conservation Committee Concurrence: Honier L. BOrrel l, ,ett~i man Alaska Oil and Gas Conservation Committee O. K. Gilbreth, Jr., Me~e'r Alaska Oil and Gas Conservation Committee ALASKA OIL AND GAS CONSERVATI.ON COMMITTEE HEARING -'APPLICATION OF THE ATLANTIC RICHFIELD COMPANY TO PERMIT INSTALLATION OF SPECIALLY DESIGNED SLIP JOINTS IN THE 20-iNCH PERMAFROST CASING AND THE USE OF A SPECIALLY DESIGNED WELL HEAD FOR THE DRILL SITE NO. I WELL NO. 32-8-10-15 Anchorage, Alaska A;ugust 13, 1969 PROCEEDINGS CHAIRMAN BURRELL: It's 9:30 so we'll commence this hearing. This is a hearing on the application of Atlantic Richfield Company dated July 2 and subsequently amended. ,An application for an exception of the Oil and Gas Conservation Regulations with respect to Section 2056 (a) which deals with casing and cementing programs. The request is to permit the use of slip joint casing and special wellhead and installati°n of surface casing without circu-- ~a?ing cement in a zone of possible permafrost subsidence in a Prudhoe Bay area wet i number 32-8-t0-15 which is located in Section 8, Township I0 North, Range 15 East, UM meridian. For those of you that don't know i'm Homer Burrell, Chairman of the Oit and Gas Conservation Committee. On my,, left is Mr. Tom Marshall, Executive Secretary, and to his left Mr. O. K. Gilbreth, who is a'member of the Oil and Gas Conservation Committee. Next to the left is Mr. Robert Larson, and 'further on the end there is Mr. Harry Kugier, petroleum engineer and petroleum geologist ,,. respectively. T. hey are within the Division of Oil and Gas and they will. serve as advisors to the Committee today. In case anybody hasn't done so, would you pieas~ Sign the register at the door either now or at' the break, or upon leaving. I would like those who are intending to testi'fy today to introduce themselves and their company.affiliatlons,~ This i's solely for the purpose 'of expediting the swearing'.ln of the witnesses and getting 'an idea perhaps' of who .. is going to offer testimonY,:.'].May l~]interruPt'one second, further, Whenever speaking, please come up to' the microphone.'~'~Piease get!'near a microphone and state your name before you 'testify today so that this tape will mean something to us if we ever try and i{'sten to it again. Thank you; MR. S1MONDS: i'm Charles L. $imonds of Atlantic Richfield. CHA' I RMAN BURRELL MR. SMITH:'"' Is there an to ":teSfi fy? i as, .' CHAIRMAN BURRELL: Thank you. MR. KEASLER: James D. Keasler, At|antic Richfield. CHAIRMAN BURRELL: I'll ask the three gentlemen that have indicated that they are going to testify to stand and Mr. Marshall, Executive Secretary, will swear you in. MR. MARSHALL: Stand and raise your right hand please. In the matter now at hearing, will you swear to tell the truth, the whole truth and nothing but the truth so help you God? , . ANSWERS: ! do CHAIRMAN BURRELL: Before calling the first witness, I~think it will be the plan of the Committee not to ask questions until all the testimony is over With, all the testimony of all the witnesses, unless there is something in the course of the testimony that we donVt understand or seems to be a contradiction which seems to necessitate an interruption at that point.' Perhap.s should there be anY questions from the audience they might be deferred' on the same basis. I'll call the first witness now .... Mr. Simons, could you state your qualifications since we don't have any evidence that you qualifY. MR. SIMONDS: Yes, i'm a graduate petroleum engineer of the Co.loradO ,~..~" . School of Mines and~hold a Master of Science degree in petroleum engineering- from the University of Southern California, have worked for Atlantic Richfield for in excess of fifteen years in various engineering assignments. CHAIRMAN BURRELL: 'Unless there are ob'jeCtions, we'wilt'accePt~Mr, ..~ Simonds qualifications. MR. SIMONDS: First, I would'~iike to get the Committee's ruling with regard to the next to the last paragraph of' our amended application dated July 22. CHAIRMAN BURRELL: !' I i read it. The sente?~ce, i 'm sure, to which Mr. Simonds refers, i'11 read: "We request, the discusSion 'of'.such~.a~..~hearing - be limited to that area above the proposed 13 3/8 inch casing shoe depth of 2,200 feet and that all other information~be considered confidential." The Committee will honor that request since the subject under discussion relates to depths above 2,200 feet and any portions relating to below that depth will be out of order· MR. SIMONDS: Thank you. Gentlemen,~our application for the excep- tion to Section 2056 (a) to permit the use of slip joint casing in the spe¢~ial wellhead installation of surface casing without a circulating cement is on a possible permafrost subsidence, is the result of Atlantic Richfield's tests and studies to date~of the permafrost, and as of this point in time, this date, our studies indicate to us that there is enough risk of surface subsidence to justify for the provision for this possible occurrence. We have developed~a method of accomodat|ng this possible futu~re subsidence and would like to describe it to you and request your consideration I think, here today,i ! would like to ask first Dr..Smith, roi.lowed by Mr. Keasier,~]to present't~.:~]O~~ ' briefly some of our studi:es and then describe to you our equipment. CHAIRMAN BURRELL~: Dr. Smith, prior to commencing your testimony, would you state~yourqua/ifications, DR. SMITH: ! am a Civil engineer, senior design engineer out of' Dallas for Atlantic Richfield· I attended the University of Texas at Arlington and the University.of Texas at Austin, Where in 1965 I'~°btained a Ph D in engineering, civi.i engineering and. engineering mechanics.' Since that time have been employed with Atlantic~Richfield;' f°r the first year and a half'with the research and deVelopment department ink. Dallas, in'Richardson, and then as a staff engineer in Da/las. CHAIRMAN'BURRELL: Unless there are objections we will accept Dr. Smith's qualifications. ., . DR. SMITH: Last year it was recognized that producing crude up through the permafrost could lead to possible problems. Since that time we have studied and attempted to evaluate these problems and have reached several conclusions pertaining to these problem areas. I would like to briefly review the work done to date, to state our conclusions and our opinions, and the reasons for these conclusions and opinions. I think we best can discuss the problem if we consider a conventionally completed well and see what could happen to that well if crude is produced through the permafrost. By convert, lo.n- ally completed well, i mean one that has say the 20 inch casi'ng cemented to the permafrost throughout its length and no refrigeration, no insulation, simplY strings of casing through the permafrost and cemented continuously to the top. Now our heat transfer calculations indicate if you produce this warm crude through the permafrost for a period of predicted life, say twenty years or eighteen years, you will get significant radiuses of thaw in the order df, depending mainly on moisture contents of the soils, ten to maybe~ ten foot radius to maybe, more probably, fifty to. eighty foot radiuses. Based on a theory of frost heaving and excess ice co. ntents in the permafrost soils on thawing, we do expect some subsidence. The. predominence of the subsidence will occur in the upper zone of permafrost, say above fifty feet.. Because the subsidence is a . function of pressures, soil conditions, gradation, types of soil, by that I mean sand, silts, clays, or combinations of.these. Because they are a function · · of rates of freezing, pressure, soil conditions, we expect the ice content, the excess ice content of the permafrost to decrease drastically with depth. And They should terminate in the upper.zone permafrost, say lO0 feet or 200 feet, the signific~nt excess ice' ]Be'il~W~this. depth we do not expect too much excess ice. Now, since we,do have ..... we do. think there:~is excess ice in this area upon thawi, ng, we should expect subsidence; and based~on~.experience in foundation engineeri'ng,.'pilefoundati]on'..engineering":~in:i~!'SaYtheGul:.~Of.New Mexico and other areas, iike HouSton leans ~:~here -are ]enCOuntered, · '~.,~ these clsys consolidate and move relative to the pile, there has bee~.' exaerienced what we call in-soil mechanics, negative skin friction, or down- drag. These forces can amount to very large cumulative down-drag force. Since the problem of subsiding permafrost upon thawing is similar but not exactly identical to this problem, I think we should .... it is our opinion that down-drag forces, on the casing can occur, especially if the casing is cemented to the permafrost. Washout areas in non-uniform drilled holes you can get significant down-drag, and also if you have a cement shoulder in a washout area you can readily appreciate the permafrost below the shoulder sQbsides, The total shoulder holding the soil above the shoulder is going to be resting on the shoulder and not on the permafrost below it and it will be transferred, this load will be transferred to the casing. Therefore, we have come to.'the conclusion that it would be prudent to do something nonconventional in the permafrost.zone, and this'nonconventiona:l approach i's.to.f:urnish, to 'use the I concept of iSOlation and"'flexibilitY O~ s~liP joint configuration'. By isolation ! mean we would isolate the.surface casing Which is the 13 3/8 from the"20 inch casing in the areas'where we expect subsidence to occur. By fleXibility or slip joints we would build into the 20 inch cas'lng the ability for, the inch casing to slip whenever large forces are encountered if these large forces are experienced,." And this is our recommendation for the'completion of .. the production wells on the North Slope. CHAIRMAN BURRELL: Thank you. Dr. Smith .... Mr. Keasler, would you please state your qUalif, ications. , . . MR. KEASLER: 'I'm a graduate engineer of the Universit~ of Tulsa with a Master of Science degree i'n petroleum engineering. I was employed with. Standard Oil of Ohio off and on for about seven years with about three years in between in the service and have been employed with Atlantic Richfield for six years, and am presently assigned as senior drilli.ng engineer for the north Alaska, or North Slope area. CHAtR~AN BURRELL: Unless there-.~',, objections, the Committee will accept Mr. Keasler's qualifications. MR. KEASLER: Mr. Smith has i,' ated to us that there is at lea~t a possibility that subsidence would, true s~sldence...we could f~ll o conven- Tionally cemented surface string on the North Slope, so this has induced uS. to iook for an alternate or d'ifferent method of completion as such, and we have designed, as has been pointed out, a slip joint, 20 inch slip joint, which ~' merely permits the 20 inch to fail prior to the actual collapse or failure~f the pipe and deformation of the pipe. We can design the failure of the 20 inch, is what i'm trying to say. To do this, again as Mr. Smith has pointed _- out, in order for these 20 inch slip joints 'to work, we cannot cement them in a conventional manner, that is we cannot cement either the 20 inch to the permafrost or either our 13 3/8 casing to the 20 inch and permit this design to work, so we have asked for. this. excePtion for this reason, What we intehd to... do ,is to iand our 13 3~8 casing on a subsea type hanger installed in the'20 inch string in the interval that is to be cemented below the maximum depth which we anticipate or might.reasonably expect some subSidence, sO.that?then the'13 3/8'will be landed again at theshoe of the 20 inch and that our inner strings will be landed in our. 13 3/8 casinghead and we have designed a head which will permit the 20 inch and 13 and the 30, excuse me, the 30 inch conductor and the 20 inch conductor to subsi'de without affecting the 13 3/8 string. This quickly is what we anticipate or what we are,...our current designs are based upon this and the 13 3/8 would be a competent string, surface string, and that our design head will permit our subsidence, our slip joint .... will permit our subsidence then without failure, of Our 13 3/8 string. That's basically all I quess we had in the way of testimony, and I would be willing to answer any questions the Committee may have. CHAIRMAN BURRELL: Does a member of~ the Committee have questions of either Mr. Simonds or Dr. Smith.or Mr, Keasler? We can. get themlall ~up.~.h'ere . perr, a~s, that may be t~e best, and you can just direct the questions to whom ~ you nay. Three can share two microphones somehow. CHAIRMAN BURRELL: Mr. Marshall has a question. · MR. MARSHALL: Mr. Keasler~ i~ there ~ p~kin~ or 8 gland in well- heads which would accomodate the change in length of the 20 inch string, that is, if we mention the 13 3/8 in. is competent to changes on its full length with no slip joints in it as the 20 inch would change its size, is there any adjustment at the surface between the 13 3/8 inch? ~ MR. KEASLER: We have a split head design which permits the addition or removal of a portion of the head and this is the 13 3/8 spool-type casing- head. When we comp'Ieee, it will be after drilling the well, we circulated warm fluids, possibly produced warm fluids. We expect that our casing strings will have been at some particular temperature, warm temperature, if ! may be~ perhaps a little vague here, but then .there may be some 'period before thais well .... we're talking about.the well we'.ve requested application for permit to drill on, is actually produced. Of course, then we might expect that .these ,~. strings will cool and contract, and this split'arrangement w. ill permit a separation and expansion or contraction of this head between the 20 inch and 13 3/8~...if that answers the question. CHAIRMAN BURRELL: Mr. Gilbreth, do you .have a question? MR. GILBRETH~: Yes, Jim, i wonder if you have a diagram of this head or anything, or could you draw on: the board wh'at yOu're .... MR. KEASLER: i have a working sketch. We do not have finished prints. This equipment went out to bid and~we do not have the final prints back but these are our working engineering drawings, and ! could .... ! don't think I could ever draw the things, and i doubt if you could see it back there; but I would be happy to put it up on the board and try to go through it if that would be of any,... MR. GILBRETH: Well, I think that would be clearer, because I really don't understand what you're talking about without seeing a picture of it. MR. KEASLER: O.K. cHAIRMAN BURRELL: It's a little early for a break, but the best thing to do might be to hang these up and let everbody wander around and look at them. Shall we take a fifteen minute break until ten minutes after by that clock? MR. KEASLER: O.K. CHAIRMAN BURRELL: You can all come up and look at it if you want .., to. (break) CHAIRMAN BURRELL: Gentlemen, let's reconvene the meeting now. We", have moved a microphone.over toward the diagrams.on the'wall and we are~going to as,k the representatives of the applicant, Atlantic Richfield Company, to explain the diagrams on.the wall, standing over. there with the microphone to run through the operation. Mr. Gilbreth, do you have a question, other than wanting an explanation? MR. GILBRETH: Jim, ! wonder if you would go over there and just run through what these diagrams show. What this head is and where the slip joint is. CHAIRMAN BURRELL: I think.if you peoPle want to move so you can see a little better it's perfectly alright. MR. KEASLER: .The head.equipment in itself is rather simple if you've taken a look at it. To start with, we've just set'30 inch'casing, we have a 30 inch clamp hub for ease of operation, for no pa'rticular other reason. Where we start getting into something a little different is in our 20 inch head and in the use of what we call jack screws Which Will permit the~20 inch head to subside and yet. for us]to'.'maintain a constant elevation ~with Our 13 3/8. Tn;s is shown pictorially here in this diagram where, actually at this paint, w~th ali strings landed and the well completed where the production and some ?ime in the future the 20 inch and 13 3/8 has subsided. It permits this 20 inch sp~it head to subside with the 20 inch so that we have a separation here and these jack screws merely are to provide a rigidity and stabilization of our 13 3/8 head. The head is a conventional unit-head type arrangement that we~ve used and mast of the other operators have used at one time or other.~' ~?'s quite similar to equipment that we've used on both the King and Spark~ platforms. So this is, like I say, conventional, and is more nearly right out of the design book, out of the wellhead catalogue that we all have. So that we run a 30 inch Conductor or 20 inch; we just have again, a simple hanger for no other purpose than to just be able to land it and go ahead about our business without having to wait on it. There is no particular change in design there. Then again, to repeat, the 20 inch head.'...the 20 inch s~ool here .... now where we get into something a little different here is when'we run and land our 13 3/8 hanger. Now you will recall that I mentioned that ,. we plan to run an on-bottom suspension-type system which will be ..... the hanger will be run in the 20 inch to receive the 13 3/8 hanger so that the weight of a 13 3/8 hanger will be supported on that hanger down in the interval that we have cemented, if ! make myself clear. We have here an opposed slip arrange- ment so that this 13 3/8 through expansion and contraction it cannot move either way with respect to this heade The head moves with it, so that permits then, if I may go over to this diagram, this head.....if we have expansion and/' or subsidence that th:is head to be supported by the 13 3/8 allows the 20 inch to subside and move away from us again with the jack screws supporting and just giving, not supporting .... .fl want to correct that ..... just to provide rigidity and stabilization. When this head, if you've seen this. diagram .... it's a three-piece split design that' permits when we have 'about~20 inches, 24 inches, ~ ~crge~ the exact measurements that will be a design function on the flna:.l ¢~s'~n print, then we can take out a portion of these screws, slip in a ..... .. ?he jack screws slip in the head, then just continue around; and if we should have subsidence of two feet say, then we just nipple back up with an extra spool and as it existed the day that we actually completed the well. i don't know if I've gone in detail or overlooked anything, or there are questions that might .... MR. GILBRETH: How deep would your 20 inch casing be set here? MR. KEASLER: We have requested on the permit 500 to 700 feet at this time. I believe Dr. Smith pointed out that we expect subsidence to a certain interval and !'il let him .... if we have any questions on that we can direct those to him. And we have allowed a safety factor in there of about two or two and one-half. This would mean that if we set 20 inch to 500 feet we feel that we're more than safe. Again, we have a safety factor of t~o or more. We will be striving, i think, for about 700 feet of 20 inch to provide for a couple hundred foot o'f cement bond then at that point. MR. GILBRETH: I believe you said that the 13 3/8 would be actually in the 20 inch by virtue of your underground hanger. MR. KEASLER, That's right. It would be supported on that subsea hanger. MR. GILBRETH: This then would be above the shoe on the twenty inch but below the'cement? , ., MR, KEASLER: Below the top'of cement and below the slip joint, yes. The lowest slip joint. MR, GILBRETH: O.K. The slip joint on your 20 inch is being designed to withstand pressure? · MR. KEASLER: The 'slip joint is 'designed to "stand 1,000 pounds.of working pressure prior to failure. 'Of course we don't expect failure until . we have completed the well and we're producing the well..'And this then is - where we nave what I mentioned as a competent 13 3/8 string. We are no longer dependent upon the 20 inch. MR. GILBRETH: Then upon final completion you'd have some sort of a pressure bleeding arrangement of the ~lip joint ~o that your pressure neYer exceeds 1,000 pounds? MR. KEASLER: I'm not sure that I fully understood that. MR. GILBRETH: Would it be possible on final completion to ever have more than .... to have 1,000 pounds on the equipment? MR. KEASLER: We don't expect that the .... the 13 3/8-20 inch annulus by virtue of subsidence will not be packed off, so that we never expect that it will .... we never ~xpect that it will need to maintain a pressure seal of any sort there. i ..... MR', 'KEASLER: Mayil.'ask"thi"s g'enf'leman to identify himself]?.......' ' With who? .... 'With who sir? (background'talking) MR. MATHIS: At'can Land MR. COLE: Mr. Chairman, excuse me, I'm Hoydt Cole with Atlantic Richfield. I'd like to point out the requirements on 2009 requests that Mr. Mathis identify how he Would be aggrieved by,the, proCeedings. , . (background talking) MR. KEASLER: Would like,,to restate this and ietme.... MR. GILBRETH: You will have a surface bleed-off valve i'n the event there were pressure in the we l l head arrangement? MR. KEASLER: We.~will on the 20,inch,, yes, But of course, once the 20 inch subsides, then there's no need. MR. GILBRETH: I noticed on your diagram on the left you have a drip pan..For what purpose is that? MR. KEASLER: Just to catch mud overflows or oil, or.something 'to · . ~ .~,~ ~' - ! 2- keep them off our gravel pads and away from the permafrost areas. It's m~re of a housekeeping provision. MR. GILBRETH: That's ali I have for Jim. I have some questions!~.~for Dr. Smith. CHAIRMAN BURRELL: Go ahead. Dr. Smith. DR. SMITH: One of your questions? MR. GILBRETH: Dr. Smith, you indicated that your heat transfer' calculations indicated over a period of 15 to 20 years that there might some significant transfer, i believe .you gave a figure of maybe a ten foot radius and it could even extend out as far as 50 to 80 feet. Is that right? DR. SMITH:" That is right. : MR. GILBRETH: Could you 91ye us a little rundown on how far out and how far down? DR. SMITH: If you assume or consider reasonable temperafures~in the profile of the crude you.can assume any type of temperatures you want and have this temperature operating for fifteen years,' existin9 for fifteen years. Your transfer of heat to the permafrost will follow the permafrost to a significant radius, 'and I have illustrated here on the:blackboard a bailpa~'k numbers or'ranges for'thawl radii versus time for a temperature of say 120°, i50 something like this over a.twenty-year period. Th~se curves do consider the various annUli in the permafrost zone from the tubing string, casing'string, service str'ing, and the 20 inch strin9 considering heat trans- fers by all means of radiation, conduction, convections; and then it assumes we consider typical moisture contents,,ice contents in'the soii.s and the specific heat of theSoils and the'conductivity of the.SoilS, And we come'up with ithis type'of prediction of thaw radius versus'time. And it is the.fUnction of the type of soils that you have; a silt w-ill contain more water, has a 'lower conductivity, it will thaw to a smaller radius'over a 9iven t~ime'versus a sand. The upper curve is for sand, has probably, very probably, and'we've:'found"in our soil Borings up there a lower moisture content. So moi'sture content i$~ the most important factor in thawing. You've got a lot more latent heat effusion of ice. It takes more heat to thaw; so, if you have lower ice content, you thaw a larger radius over a given~time. And the top curve is for sand and the bottom curve is for silt. Now, the curve on the right is another ballpark number that can vary slightly depending what you assume the soil, the conditions of the soil are, the permafrost soils. I've shown two curves here, the firs? curve is what we, is a conservative estimate of what the movement versus depth will be in the permafrost on the North Slope. If you thaw out say a ten-fifty foot radius, how much thaw or movement do you get for elevation. At the ground surface'you can reasonably expect ten feet, fifteen feet, maybe twenty feet of subsidence. This is of course if your island is located over a large mass of ice that's five foot thick r!~ght at the top. We don't plan to locate these drilling islands over theSe large masses of ice; but if you~ did · you could. You automatically have five feet of subsidence right ~there. We expect the subsidence to end somewhere in this zone. As I said during the initial testimony, the mechanism that .... there is various mechanisms that leads to the crea±ion of excess ice in soils, in the~ silts, in gravels, and sands in this permafrost soils; and evaluating these various mechaniSms, a classic one being frost heave that you experience on the highways and fo~unda- tions .... build.lng fOUndati~ons, the classic frost heave phenomena. This is influenced greatly by the amount of pressure you're heaving against and ~as pressure goes up, or as you go further down into the ground, you quit heaving, you quit creating this excess ice or ice thickness. Using that, using how we think the soils were layed'dOwn to positiVe 'and frozen dUring the formation of permafrost, we think it's all normally consolidated and then frozen from the top down. The various other, two other mechanisms, we have come up.with a predicted curve~ expected curve, and this is conservative, probably'.would end -14~ somewhere ua; but this is our expected, conservative expected curve. And this is our design curve, a factor of about two point, two-five, somethingi like this down to four or five, 500 feet. This is the zone we are trying mo protect the well casing from. We might point out, Jim, that on these slip"., joints there is a high probability that the slip joints will never fall. These slip joints are positive open slip joints. They have a set iow that,they 'will fail at. In very high probability, the slip joints would never fail and slip or shrink; but if the load does get high enough on the 20 inch, the slip joints will fail and relax the load. This is, I think, an important point"~ We don't think we'll ever fail these slip joints, but we have this safety factor; and several points removed from the 13 3/8 inch. MR. MARSHAL'L: Dr. Smith, Tom Marshall. About how many slip joints do you anticipate you will use in a single well operation? And where is their typical location? DR. SMITH: We expect to use four or five slip joints in the 20 inch. MR. MARSHALL: And they're to be staggered throughout the string. DR. SMITH: Yes, the spacing on these slip joints is governed by how much. what's the maximum unit load transfer~we expect to occur from the · sands. What is the maximum negative skin friction we can expect. If you take these numbers and you'll come up with four or five slip joints will · safely guard the 20 inch in an area having a compressive failure in the body .. of the, 20 inch it will fail the slipi'joints and re'lax itself~. MR. GILBRETH: 'After Your initial subsidence occurs according to your second curve there, will you have relativel'y competent ground mass around your. casinghead? DR. SMITH: You're saying in the top 20 feet or I'0 feet we will not _ have a very competent land mass or soil mass when we have a thaw. It'll be spungy but we'll have five foot or six foot of gravel above this; this is',. sii~i- or silty sand. We expect very rapid consolidation and compressing together from this. MR, GI~BRETHt Well~ if y~ j~t 1~ at y~r ~urve ther~ say at about 50 feet, does this imply that the area of say four or five feet away from the well bore is essentially incompetent? DR. SMITH: If a very soft soil, could be at particular times; but we have looked at this and on the column action of the 20 inch casin'g in a very soft clay on a soft soil, a very weak, and by that I mean a stiffness, not strength, but stiffness, you need very little stiffness or stiffness of .o~ the surrounding mediUm to hold that column in a stable position. This is well illustrated in the Gulf of Mexico in very soft sediments. YOu have free- standing conductors standing in softer material than this permafrost will be, ,, You have well casing standing in very soft soils for several hundreds o~ feet in the Gulf of Mexico right off the Mississippi Delta. Theoretical computa- tions show that a column can stand if you have a very soft soil surrounding it and field experience says it can stand also. MR. GILBRETH: As your curve approaches the zero axis on ground movement there, is this becuase of th~' composition of' the permafrost itself? DR. SMITH: It's because of the ice contents of the, or predicted contents of the Soils and some measured ice contents of'the soils. We have . taken some soil borings, it's very difficult to ~btain soil borings undis- turbed cores of the permafrost soils, mainly because they are, we think, undersaturated with ice in a lot of areas. We. have obtained samples in the upper fifty feet Of the'Silty sands that were ConsOlidated, let's say saturated with ice and we were able ~o drill a core. Down deeper.we had difficulty sampling some of the gravels and some of the sands.because they were not Sat- urated, not bound by ice~ And this illustrates that':'when~that ty:pe ~f'material thaws we will probably not get any Shrinkage beca~use we'don,t have'the ice ho~ng the sand or the soil particles apart. MR. GILBRETH: I believe in.your statement there, initially with the effect that this may occur up to a radius of about ten feet, but you stressed it could even occur from fifty to eighty feet out. DR. SMITH: Yes sir. MR. GILBRETH: Would this imply then that it might be an unsafe practice to construct anything with fifty or eighty feet of well bore? GR. SMITH: No, you construct buildings on subsiding soils all the time, in soft clays, you just watch out for your bearing capacities and you anticipate this subSidence. Now what we plan to do on the North Slope, around these production islands is to maintain a constant ground elevation or island elevation. We will bring in gravel and fill up where the thing subsides. This is occurring over fifteen years. We expect only ten feet of subsidence, something like this. So we're saying we're going to have a fifteen foot island there, maybe, at the end o~f twenty years, and this is the way we~will approach that problem. We will design our piping, above ground piping to .... where we'll be able to jack the piping up or maintain a constant level of the piping. This won't be a sudden moveme~nt, it will be a gradual consolidation sluff~ng down on thesoils. MR. GILBRETH: Your calculations indicated that the drag forces you mentioned due to subsidence are enough to collapse the casing, actually collapse : it, bend it? DR. SMITH: This negative down'drag, the type failure you will get on the 20 inch or any pi'pe in the soils will be a.compressive type failure of the pile wall and it won't'buckle theSe...,the section ,of pipe we're using will fail in plastic yielding in the actual sense, in our numbers, based on · numbers from, as I said previously in initial testimony from negative skin friction experience in soft clays and some in silts, ShOW that you should design fo'r large forces that are enough to fail'your pipe wall'. Andthis i.s -17- ~r,a-h '~e've done in the slip joints, Now, as I said previously, this is not the same problem as consolidating clays becuase the main poin~ is we've got' sitTs and sands; and also, another point is, we're moving radially outward. it's not a uniform consolidation of a big mass of clay around the pipe, if you please, but is rather a gradual radial thaw and subsidence radially and this tends to...maybe you build up a load and then you relax it if something stuffs off. It's an inelastic phenomena, it doesn't all build up on'you continuously, so I think we are being very conservative in our predictions .of negative skin friction but we don't understand it enough to be less conservative. MR. GILBRETH: Is ARCO proposing this as an experimental type deal or .... I realize that this is just for the one well. WoUld'you be continuing to study this problem on this well after the installation is made? Is it experimental to that extent? DR. SMITH: We-think it's a prud. ent conservative design approach. I I would not say it's experimental. It's an engineering design for a problem that we anticipate. We will, we are and we will continue to study this'.problem. We have several research 'programs going on if you want to use the wor~ research programs, study programs in the field and in our laboratories. To try to illustrate or to confirm our thinking about this depth of subsidence, we'll f'reeze samples, we'll watch them swell, we'll, vary the overburden pressure, vary the rate of freezing, see if our .thinking is right., confirming in the lab; and also we anticipate to confirm this in the field with the field experience, the depth of subsidence. MR. GILBRETH: Those are all the questions I have. CHAIRMAN BURRELL: I have a question. I don't particularly care who answers, whichever one of you gentlemen who wants to. Would ARCO have any objectio.ns in view of the uniqueness of this experiment to a requirement that certain tests be made by you and the observations during the course of the operations and certain research data that has been obtained might be"made available to the Conservation Committee? Would you object'that informatioh being required and made available to us on a confidential basis? DR. SMITH: No, Mr. Chairman, we would not object. CHAIRMAN BURRELL: That's all I have. Mr. Marshall, do you have a question? MR. MARSHALL: Dr. Smith, has there been any actual operation of this nature in places in the world that you have knowledge of, to a failure. of a 20 inch casing or equipment has occurred. Are you anticipating this particularly on the basis of an abstract basis of engineering calculations~ or has there been some practical occasion where this has failed that you know of? DR. SMITH. T~ere has been none .... we have tried to .... we have searched out that questioned area there and we have no knowledge of failures. Now there have been failures and problems created by similar problems i~ production wells, in sulphur wells producing sulphur dome you produce a porosity sulphur sluffs on you, matrix sluffs on you~and it has caused some failures. You have failures due to some subsiding .... industry is putting slip joints there. ^s I said previously, these large forces that we are~designing for, anticipating, conservatively anticipating, is due primarily to the experience reported |n the foUndation work or'civi~l~ engineering workS. A typical example, i don,t know which country it is, it's a European country, there is a bridge constructed over a river and the'~bridge piers are supported by 16 inch steel piles driVen~to 1~50 feet into bedrock. The pile tips are bearing on rock. They came along and Put a ten foot overburden pressure on the bottom, on th~ channel bottom, and this started consolidating this 150 feet of clay; and With this consolidation, they measured by, measured stresses,~ · indirectly by measuring the shortening of piles and these stresses came up . to 20,000 psi, compressive stress in the piles, axial compr~essive-~stress due only to the subSiding soil. They aireadY~had the~compressive stress off.the bridge. These type numbers, if you extrapulate them over three or four h~indred fe~T and then also put the tubing casing .... tubing loads on a 20 inch, you' get up to pretty high loads; and especially if you put a cement shoulder out there. This is one of the main reasons we don't want to cement the 20 inch. MR. MARSHALL~ Is your production string conventional in every other respect or pratically .... DR. SMITH: ! dOn't think so. I don't think the 13 inch is conven- tional either. It's fairly heavy. MR. KEASLER: No, our 13 inch design is 72 pound. DR. SMITH: The 13 inch is designed to stand by itself inside the 20 inch, it centraliZes this well. You do this off shore also. You stand the 13 inch .... the 13 inch will stand inside the 20 inch and carry its~yield body yield il, oad without buckling because it's constrained. 1 MR. MARSHALL: Thank you. MR. GILBRETH: I have one more question. I beli~eve you mentioned that y~u expect to make this installat~ion on a~particular well in areas where you have this particUlar composition of permafrost. Are there other areas on the Slope other than this well where the same situation might occur? DR. SMITH: This design is .... this is a general condition up on the North Slope. MR. GILBRETH: ~ It's something that might occur anywhere on the North Slope? Well, in the permafrost areas? DR. SMITH: Well, I could not say that, because in this immediate area, say in the~ Prudhoe Bay area, I would say yes to your question. If you move further south you may have completely different soils. Move up cloSe to the Brooks Range it may be all gravel, it may be all clays. Clays perform differently than sol'Is. MR. GILBRETH: Within the radius of a few miles from this particular well you might expect somewhat similar,conditionS? -20- DR. SMITH: Yes, I don't see how you can expect otherwise. MR. MARSHALL: Dr. Smith, on your diagram here permafrost setting- have an area delineated here. Does this mean that this part would be a ty~ical slip joint in the .... this would be 200 feet down in the hole,..or does this have the .... on the wellhead? DR. SMITH: That's on the top of the wellhead. This 20 inch, as I said, we do not expect the twenty inch .... if you're a betting man you'd bet 99 to one odds that the 20 inch will never go down, will never fail the sli~'p joints, will never fail, but even with these odds you've got to put these things in. If the slip joint does fail it just moves down relative to the 13 inch and if you get enough gap in there you'll just come along and put an extension on the 20 inch. MR. MARSHALL: Well, could you point out on the diagram then just what the slip joint assembly will be? DR. SMITH: Where i.s your slip joint assembly? We don't.have a slip joint up there do we? ,MR. KEASLER: The slip joint is.a 20 inch design in that it will be run at depths below the surface, spaced by theoretical determination as to':] .... ·. - . where 'the loading might, possibly fail the pipe, so that they will be spaced .... somewhere below the surface begi~nning,:, well, below a hundred feet and we anticipate possibly-two'to four,or .five, as Dr. Smith mentioned, .depending .... that woutd depend....like I say, on exactly hoW much sUbsidence you anticipate, whether we're looking at 180'to:200 feet or whether we're looking at 500 feet. For this design, i think we requested the use of two to four slip joints and our intentions are to use four spaced somewhere below lO0 feet So that this if off-surface equipment. ,Your slip joint functions below the surface allowing the head to subside. If this portion here then would subside, this portion would remain~at a constant elevation level throughout theprOducing life of the MR. KUGLER: Jim, what is the maximum slippage? MR. KEASLER= We have designed for a ten-foot stroke in either direction so that we could get an elongation of ten feet, or we get a slippage and compression of ten feet, ten feet in each joint, in each direction. MR. KUGLER: And you put in from two to four so that you have 20 to 40 feet of subsidence or expansion. DR. SMITH: You'll get afpreciable slippage of sand in the top 50 feet before you'll get any failure or large enough load so this flexibility in the slip joints, this 40 feet of cumulative slippage we anticipate never will be taken up. You'll only need two or three feet really because there is fifteen feet of subsidence which will occur in the top 50 feet. The movement below will vary. MR. KUGLER: I wanted to ask ye.u, on your curve here, your design curve, at the depth of about 400 feet. Does this indi'cate that the he~t loss from the fluid being produced will not cause any subsidence because of the pressure at that depth?. DR. SMITH: No sir, we expect the permafrost to thaw througho.ut its length, throughout its depth. This termination of shrinkage or movement, significant movement, at 200 feet or our design curve of 500 feet is based on what we think the ice conditions are in the soils, does the ice .... excess ice .... is it holding the soil particles apart and upon thawing will the soil particles move together. We think-this terminates in the upper !00 feet or so, based on our understanding of what causes excess ice to form in the soils.. We expect ice to exist throughout the permafrost but the ice does. not hold the .... the permafrost soils are not swollen, where upon thawing they would shrink. They will not do this. MR. GIL.BRETH: Dr. Smith, you've used the word failed several times in your ~estimony here. DR. SMITH: I've tried not to use that word .... function! MR. GILBRETH: You actually mean the point at which the slip joint starts to move? DR. ~MITHI Ye~ ~ir, the~e ~lip jeintg h~ve e pggitiv~ ~he§r megh~ni~m. They have been tested and they fall within the range of shear values that we have designed for; and when this load gets up to this magnitude, the slip joint will function. The shear pin will fail then it will be a frictionless or a small friction .... small load will make this slip joint function. Strike the word fail from my testimony. CHAIRMAN BURRELL: Are there any further questions from the Committee? Unless ARCO objects, I would like Mr. Marshall to mark the two chart drawings on the wall and the one of the slip joints on the table there as exhibits A, B, and C, and they be entered as exhibits to this hearing. Are there any further questions from the Committee? .... In accordance with SeCtion 2009 of the* Conservation Regulations, a hearing will not be required unless a party'objects, · a party, who may be aggrieved by an order as issued. We have received no suCh objection prior to the hearing. If any partY here wants to object at this time, to give testimony or ask questions in connection with this, the Committee will require a showing that you would be adverse:l.y affected by the requested order, if issued. We will rule on your statement as.to' how you would be affected. Is there anybody who wishes to make such a statement? .. The meeting is adjourned. AFFIDAVIT OF PUBLICATION STATE OF ALASKA, THIRD JUDICIAL DISTRICT, ) ss. being first duly sworn on oath deposes and says that .... ~i?.~ .... is thei.~[~e.~,..~_...~.>.~..~.~,_, .. of the Anchorag~News, a ~EJl'y news- paper. That said newspaper has been approved as a legal news- paper by the Third Judicial Court, Anchorage, Alaska, and it is now and has been published in the English language continually as a daily newspaper in Anchorage, Alaska, and it is now and during all of said time was printed in an office maintained at the aforesaid place of publication of said news- paper. That the annexed is a true copy ofa---4'-, =,'~r~ .... ~f~ as it was p0~er~;~ in issues (and not in supplemental form) of said newspaper for. a period of .....~f)~:e ...... insertions, commencing on the ..~ ........ day of ..71%[~?J::¥k ......... ,'1969:., and ending on the .........~ ........ day of . ~.~ '~ %, ~" ............... gfotH'~'~:'f~;''~ J~clusive, 'and19...... that such newspaper was regularly distributed to its subscribers dur- ing all of sa.id period. That the full amount of the fee charged for the foregoing publication is the sum of $ 'j~f.f').()which amoun~ has been paid in full at the rate of 25¢ per line; Mini- mum charge $7.50. Sub~~w;;n to bef~}; me this ";' day of .... .':b-w=~?~ ~z. Notary Public in and f'~' the State of Alaska, Third Division, Anchorage, Alaska MY COMMISSION EXPIRES // ~ ......................................... . ~o~c~ ...... ~,I~;" ..... A~"~O'F NATURAL DzV~s~6~..-~._. ~ .' ' ' ¢, u~ ~ND , ~lasKa, Oil',and ~as COnservation '," ............ ' '~,'~'~:,~mi~,- :'+:'~:' ~' ~e '" · the re. operator l~eartng ,..for an exception to '"~ :, , Section 2056 ..1~, .. ~ ....an~ ,,-~ ~ . . (a) ll "~egulations ......... ,~ ~, ..qgnserva~ion :j .~:~..?/.~,~.. : .'..; ..... .~ :, 'Lo': ma rs;~0f, the, Z..J. ll ~/ ':u'ssaC Ltbrary~..~..Fttth..~Aven~ and I.,F,~. Street,. ~nChora.g~¥Alisk~,' j 9~30 . a,m.,...~u~.u~t.: t~,.~i~,~ %'.whiCh l.'tfmg :.the: '0p~it~'r'wi.ll. ~e"i e ' .' affected and',~in~erested ~i',~?,,'"': :%; '.'. ~,'. '~ ' 'd,'- ~ . , ?:~- ~,~.,~ ~..'~2'~.~.~.' .... '" ' E~'~fiVe Seeret~:l;~ . ' ' 'J 'ConServation Commit~ "~ 3001 ~.Po~cup~e Drive . j ' Anchorage, Alaska 99~4 'JPu~lish: .Aug. 2, i989 NOTICE OF PUBLIC HEARING STATE OF ALAStGq DEPART!iENT OF NATURAL RESOURCES DIVISION OF OIL AND GAS Alaska Oil and Gas Conservation Committee Conservation File ?.Io. 78 Re: The application of tile Atlantic Richfield Company for an exception to the Oil and Gas Conservation Regulations to permit use of slip joint casing and a special wellhead and the installation of surface casing without circulating cement in tile zone of possible permafrost sub- sidence in a Prudhoe Bay area well, Drill Site #1 - Well #32-8-10-15, located in Section 8, TION, R15E, U.M. Notice is hereby given that the Alaska Oil and Gas Conservation Com- mittee will hold a hearing pursuant to Section 2009 of the Alaska Oil and Gas Conservation Regulations to hear testimony on the request of the operator for a hearing for an exception to Section 2056(a) Alaska Oil and Gas Conser- vation Regulations. This hearing will be held in the City Council Chambers of the Z. J. Loussac Library, Fifth Avenue and "F" Street, Anchorage, Alaska, at 9:30 a.m., August 13, 1969, at which time the operator will present testimony and affected and interested parties will be heard. Thomas R. Marshall, Jr. Executive Secretary Alaska Oil and Gas Conservation Committee 3001 Porcupine Drive Anchorage, Alaska 99504 Publish August 2, 1969 AHarrlicRichfieldCompar~y North Ameri~,~;"~ Producing Division A~aska Dist~ Post Office Box 360 Anchorage, Alaska 99501 Telephone 907 279 1411 July 31, 1969 'TRM ~ OKG KLV . ./ REL FILE State of Alaska Department of Natural Resources Oil and Gas Division 3001 Porcupi ne Drive Anchorage, Alaska 99504 Attention Mr. Homer Burrell Gentlemen: With reference to our letter of July 22, 1969, and the accompanying Applications for permiis to Drill, please cancel our Application f~ Permit to Drill Well No. 32- 36-11-14 and amend our letter to include only Well No. 32-8-10-15. ~-A/qry truly yours, James D. Keasler Senior Drilling Engineer JDK' ve AtlanticRichfieldCompany :~, North Americ,~ Producing. Division Alaska Distri~,~ Post Office B~X~ 360 Anchorage, Alaska 99501 July 22, 1969 State of Alaska Depart~nt of Natural Resources Oil and Gas Division 3001 Porcupine Drive Anchorage, Alaska 99504 · .,, KL¥ HWK REL -- Attention Mr. Homer Burrell Ge n t 1 eme n' SUBJECT: Drill Site #1 - Well #32-8-10-15 Drill Site #2 - Well #32-36-11-14<- c~,,., il-ej (.~.~., l..,a.~,. ?/~,/~ The Atlantic Richfield Company is engaged in a study of the effect of producing oil from wells completed through the permafrost, Alth'ough the study is not complete, present indications are that permafrost subsidence due to thawing may poSsibly occur'to depths of 200' to 500'. Dr'~g of the sub- siding soils:would fail the.casing of,a well that is conventionally cased and cemented in accordance with Regulation 2056(a) of the Oil and Gas Conservation Regulations and Statute of the Stab of Alaska. Our study shows that the forces of subsidence can be withstood by installation of specially designed slip joints in the 20" permafrost string, by isolation of the 13-3/8" surface casing from the 20'! permafrost casing, and by use of a specially designed wellhead that enables the 20" casing to move relative to the 13-3/8" casing and allows the 13-3/8" casing to carry the load of the inner casing and tubing strings. To control the loading of the 20" permafrost casing with slip- joints it is essential that this string not be cemehted in the zone of subsidence.. It is also essential that the 13-3/8" inner string not be cemented to the 20" permafrost string in the zone of sub.sidence through whi,ch the slipjoints are installed. In order to protect producing wells from possible subsidence, ARCO's present design Of 'devel~opment well casing programs incor- .p.orates 'the special permafrost subsidence equipment as .described above. This design is propo.sed for use in the two subject development wells for which ApplicationsFor Permit to Drill are enclosed. Therefore, Atlantic.~Richfield requests exception to Regulation 2056{a), as it pertains to the 20" permafrost and JUL lg 9 DIVI~IONOF OILA~4DGA$ ANCHORAGE State of Alaska -2- July 22, 1969 13-3/8" surface casings only. Specifically, we request exception of that part which states "Surface casing ... shall be cemented with sufficient cement to circulate to the top of the hole. If cement does not circulate, the annulus outside of the casing shall be cemented before drilling plug or initiating tests." We also request permission to use this special permafrost sub- sidence equipment and cementing program on additional wells that will be drilled in the same general area, with permission granted by administrative decision without further hearings. We realize that notification of our request will be made to other operators and that a public hearing may be required. We request that discussion at such a hearing be limited to the area above the proposed 13-3/8" casing shoe depth of 2200' and that all other information be considered as confidential. Enclosed you will find Applications for Permit to Drill, location plat and the $50 filing fee for the above referenced wells. Very truly yours, ~ Senior Drilling Engineer JDK:ve Enclosures ANCJ-IOIJAGE F-VETCO TYPE "I'PItV ~-- PF~EGET 5HEAt~ i~iVD ~ , \ INITIAL 5EA£ DEVICE VETCO M IAI. Dt~IFT 20" O.D. IL). I ~? ~Y~'' DESIGN CAP~CITI£3 T Y'PE I ,.~t-iE,~R D~HC~ ~'FORE FAlL URE ,,,'1,filM. TE I'V,5 / L. £ G'TIq£N~ TH TYPE ~ ~o~Y I~ 0?2, 000 II L -- ,_ MPX. T~'At,~ I£ E OR C Ot~41F::~I~'E,S$1V~ ~VI/N, /IVTERNA~ L IRE3/6 TA NCE r : 1,000 P,51 ........ z, 00o ps/ 0 I00, O00 L~,S. -- 5O 0 PSI ?~ 0, 000 I00,, 0 300 laS/ 0 PS1 CO Date Revision AtlanticRiChfieldCompany North American Producing Division Orillin9 Engineering Group Dallas, Texas PERMAFROST ~111~ JOINT IO'OP£1VlNG ~' /0'C£ O,5/NO TRXIV£L (PATENT IlPP/-//:[-) FOR) Drawn Checked Project F. tngir~er~-- Scale NONE Approved Supervisor Manager LDwg. No. JEst. No. .,,,...o.