DK201200785A - Shape memory cement annulus gas migration prevention apparatus - Google Patents

Description

HELD ΐ)Ρ THE iNVEfffiOH J0Q01J The field of tiiis mventionris devices that niiatedze of prevent gas migration through femeni in an annular space: mound a tabular -sx.ieadta| to a subterranean teat.i<:m.

BÅ<%GEOlJMD OFIME INVENTION THftdar strings Lave been seated is bores with cement. The setting cenaeid can shrink and pull away irom the tylmlaf on either side bf åa annular space nr it ban phll away ifem a borehnle wail in an opes bole <tementrag application, There ca n be other causes too such as incomplete mud cafe removal or incoihgtete drilling fitiid removal prior to peøæiiSng. Subsidence and coisptaciion. Craefe pah develop later oa due to tectonic activities as well. The present invention focuses on gp migration through the set .'cement as opppsecl to midgatiM Of ciaeks or openings develt^ed afts* the cement is set. Gas migration through cement eaa be a dangerous situartenand is one Ofifhe discussed causes of the Deepwatp ijiaiizon accident in the Gulf of MemcOi: pOOSf Early· rifiriris to counteract gas: migration in cement, dealt vritb: methods of deliveringdite cement Or the addition of additives to the fementast illustrated by;USF5,;3t756%: 5:5:03,227; 5,189,48¾ 6,936574: 7,050,129 and: 7,373.981.

[0004] In a wholly nirudaMiEekl ofartiftciai Mp joints shape Memory stfacMreS wens psed to retain iifetion cement for the hip joint as described-in USE 6;28iL477.

[1¾¾ Other applications:; have involved pacfers in. the: annular space that tedye channels før cement and use a variety of biasing devices to ggt the seal materia! of the packer against the borehole wall In IIS Publicaiibn 2010/01,26735 ElOS. 2 and 3 a base pipe 56 has support members 54 shat leave gaps in the annular space 38 ibr cement to pass;. In the FIG. 2B embodiiileM she member 54 is a shape memory material designed to apply an iftcrorøsntåi force tø the swelling member 42 ©ff bf die tabular S& to push against the formation 36· Εν&η. as to the fetfoufe wall at 36 these are shorteomrøgs. of this design ilt preventing gas migration along foe borehole wall The swelling material e&h be damaged daring Mn is to foe point of openings developing: in the swelling layer. 1¼ cement in the- annular- space can. still pull away from the seal 42.eves, if ail else fencdofts as planned if the smmeiit experiences shrinkage fori causes it to pull away hot only from foe spai 42 hue also from foe tabular string: 54 1«] Another attempt at. dealing with cement gas ftngratipn was m effort by Halliburton: to use rubber sleeves Oft foe tabular exterior so that foe sleeves am in the annular space. The idea, was to pump foe cement into foe annulus before ibe rubber rings swelled tø hopefully span foe annulus: with foe hope that gas nrigratipa at the tabular eOuld be stopped: with a bonded: seal: of foe mhher and that foe sleeve would push the cement away as it swelled to the borehole wall before foe cement; set up The problem. with the design is that foe swelling process was so slow foal foe cement would set ahead of the. swelling sleeve so that foe outer diameter of the sleeve would never react foe borebolfe wall and foe same issues of gas inigrations would still be: there as foe. cement got to foe borehole wall and the sleeve outer diameter and. shrank: from both on .setting: tip, leaving open passages at both loeatioiis for gas migration, [0007] Muliistafrte struetxtM members are described.in US! Publication 2009/0186194 [CM)Q8J The present invention addresses the issue of gas migration in a new way. It employs shape tpemory material structures that are secured to foe tubular: at. one end and that when reverting to aft: original shape, spån foe annular-space by displacing foe cement that has yet to set until contact with foe Open .hole or wellbore wall is Triads that puis the radiating eietnents of foe sixactare: under a compressive load to seal Or at feast iainimize gas Mgration between ^opes. through, foe cement Optionally, foe shape memory or bistable; stfUGfttres can be covered in whole: or in part wifo a swelling material. Those and other features Of foe present invention will be more readily apparent to foose .skilled in: the art from a review of the description of the protested embodiment and the associated drawings' wife ao. imdttastsrGfcag that the foil scope cl the invention is determined ftpis the appended. claims,

SUMMARY OF TIlE.MVENXiON prøj The .annular »pace around a tabular string has a shape memory material that is in a low |»ohk configuration for .ran in, Alter fee desired: posilion.is obtained and fee anmfejs has cement delivered to PI! the annaiar space* die shape memory denes is triggemd to iwert to an original shape that spans the arimstøs: to seal the mbul&r vand the wellbore sides of the annular space against gas. migration through, the cement. The straetores can have taiying/fus. in shapes and can: :aiso lisve original shapes that when the material is ttiggeiod will act to displace cement to enhance its compaction os the tubular or the wellbore wall. Combinations of shape memory alloys and poly mers are also contemplated to enhance the seal against gas migration. An outer eqati ng of a swell material can be used, BRIEF DESCRIPTION OF THE .BRAWM'Gfe [W1@| HG, 1 is a section view of a gas migration barrier during tun. in; [0011] FIG. 2 shows the gas migration barrier deployed; [001.21 FIG. i shows deployment of the barrier that can start m die middle and progrtss to the opposed, ends to displace cement; [001¾ FIG:. 4; illustrates a capability cif tile barrier to act as; a pisten to displace ceirtent into enhanced contact to the formation and the. tubular that define the annular space; [0014] ETG< '5 shows one configuration of: the gas migration harrier made up of parallel discs in the initial shape before rmt in; [0015] FIG· 6 is the view of FIG. 5 alter application of compression above the tfansmoh temperamre and removal of the heat: with compaction fosses still applied so that: a low profile shape- is maintained; [0016] FIG, 7 shows revCmion to the original shape at the formadqs when the tempemhire again crosses the teanshion temperature; [001 Tf FIG, § shows the use of solid rings or a coil. in., an: mittal condition before compaction to the. supporting tubular; [OQISjj HG. 9' is the view of MG, 8 after cbfiipaerion at above the: transition. temiperahsre and .removal of the teat while still eompacUag ίο hold the 'low profile shape that & depicted; imwj HQ, 10 shows a. series of rings or a boil: where shape nteimay polymers are hacked by shape memory alloys before compaction at above the: •eriikal tentpemoro takes place; [0020] FiG, 11 Is the view of HQ, 10 after cMpaction. at above the transition temperature followed by removal of the bear while holding die compaction force to get a low profile før mn in; 10021] MG. 1.2 is the view of FIG. 11 when 'the transition temperaime is crossed sear ifte. formation; P022] MCI. 1.3 is an alternative embodiment ia its original shape of art sngnlar simeture; [0023] FFG, 14 -is the view of PIG. 13 after crossing the transition, temperainre and applying a compressive force folio wed fry heat, removal while holding tte compressive force to get a low profile of the gas migration barrier for η® in; Ρ024| MG. ift is the view of FIG. 14 with the transition te-inpeMure crossed at· the .formatioa and die barnet re verting tø its original FIG, 13 shape; [002S1I MG. lb is an alternative embodiment Ιό FIG. 5 with a swelling; material around the projecting members and between the tutelar and the gas migration harrier; [002S] HQ, 17 is die view of FIG, 16 after the corhbined application of heat and compiession followed by removal of heat while maintaining compression to retain the illustrated shape; £003.¾ If G, 1:8 is the view of HO. 17 after the addition of heat. at ifte: desired location so that the shape attempts to revert to the initial FIG. 16 shape and the swelling material Swells tø enhance the gas migration barrier perffimance. BETAILED DBSCfelPTrøM OF THE PREFERRED EMBODIMENT wm If G, 1. shows zones: 18 aMJ.2 of a.Toniiattpn where them is a borehole 16 that has a string 18, in this example being casing, and a gas urigraiioa device 20 in the armuiar space 22 that will be filled with cement or anoffier sealing inatefeal 24. in fee run in position the device 20 has a low profile annular shape, and is preferably made of a shape memory -material. Of the available shape memory materials: an alloy is fiirfeer preferred. Other iMieaals: that can be ran in with a smaller profile, and fees converted to another shape or volume w> ils & stimulus that is added to tire bore 14 or oses fee -fluids in fee bore 14 can also be deployed such as bistable materials triggered with a mechanical /impact or bending force, Bistable materials can be used in isolaricm as. a gas migration device or combfesed wife, shape memory materials to aid fee tpsisfbimaiiQn of fee shape feemoty device when revetting tø mi original shape. P>20] In MCI. 3 the exposure to well fluids has imparled enough heat, to fee device 2© to alow i.t to revert to an original shape feat: is larger than its nan in shape so that contact wife the borehole wall .16' is achieved while the cement 24 is pushed out of fee way. to this configuration, there is a seal to fee tubular 18 me fee borehole wall 16 by fee device 2®. 'I'he device 20 in the Fi.G. 2 configuration has Internal compressive stress fern pushing against fee borehole wall M on cine side and against the febtdar 18 on fee-opposite side. There: are no issues of eemexte shrinkage: as the seal is made in a zoue where the cement is displaced before it has had a chance to set up. As an alternative to fee use of the well fluids to get fee device 20 across its transition teaiperature so that it can revert. tø an original shape,; auxiliary heat U can be added to; initiate fee teatssfomtatioa and hiamtam it to the end position, iflusfrated in FIG. 2. Another available soutee· foi -heat, em be fee heat given off by fee cement as it sets or .horn reactions between or among ingredients or additives to fee cement M._ A shape memory allay for fee entire device 20 is preferred as alloys will create more compressive stress when abutting fee 'Wellbore wall M than for example a shape htoiMfy polymer. However, alloy and polymer, shape memory maten åls can also be edsiVbraed in å single device or different compositions of alloys or polymers can· be used in a single device as will be discussed below. jCMQ] HG. 3 is iMustrative of using a mix of materials risål trigger at drffersiit temperatures to revert to an original shape so that the cement 24 can be more efficiently renrøved iroffi between trie growing- device·" 2# and the. wellbore wall IC frir example HG, 3 shows a portion:.of & shape Mrinrery alloy 26 triggered to.revert to toe original shape .from the middle-of the device 2d so that trie cement is initially pushed toward opposed ends as indicated by arrows 28 and 3®. When the temperature is ftrte incisased to a higher level either using: the well .fluid or external·, sources such as H, other segments such as 32 and 34 will start- in seguenee to change shape and any cement 24 between those segments and the wellbore: wall. 16 will he pushed Out beyond;, the opposed ends of the device 28 in trie direction of arrows 2§ and 38.

[0031] HO. 4 illustrates a different application of Materials that revest to ait. original shape at differing transition temperatures. I« tills case the segment M moves·.first and acts as a piston on the cement 24 to drive it to ward the weilbore wall 16. Ultimately on reaching an even higher logger temperature, trie Segment 3S will begin to revert to its original shape, winch i.\ not necessarily the same as the. original shape of segment 36. Those skilled in the aft will appreciate that the shape change on reversion that is triggered by crossing, the mansitton. iemperatoxe can involve change in volume to some degree as well as a more dramatic change in shape·. In this example the mieritai pressure in the ereritetii.; 24 is raised: by the device 26. Arrow 46 indicates that there Is a one way flow of cement 24. into the annulus- 22 usually through & cement shoe that .has efieefc valves to prevent cement backflow. Thus the use of the device 20 as a piston is also operative to reduce gas migration· through trie cement 24 even without ibrefeg out tire cement from trie enrire length of the device 2ft: P032| MG, 5 illustmtes a: design with: an atærilarfy shaped hub 42 seaiagfy secured to an outer surface of a tubular string. J.å -with a scries of discs. 44 having.an Outer end 46. When this shape is reverted, to in the- desired location it is intended that the ends; 46' engage the fermation suck as 11) or 12 to a manner where toe disc ends 46 are compressed, arid even. slightly Misshaped as shown in FIG-. 7, The shapes 44 can be equally spaced, sr randomly spaced. The: outer, shape ai 46 eaa. be circular oar xeet&ngular or another shape designed to make .fully circtonferenti&l confect; witii the wellbore tQ upon shape reversion when crossing the transition temperature, tire original shape of MG. § has: to he seduced in profile fcrroftjjiBg in to the FIG. 7 location. This is done by applying .-compression- while increasing ihe built temperature of the device to above the transition temperature and then holding the compressive fereg while teduemg the tpmphrstars Of the device 20.. la the Ρΐϋ.. 6 eoftbgursdan, the extending iriembérs" have bees flaitened into an. essentially anuu'kr shape with a. fairly low profile as comparing it to toeorigMd shape. Note that she extending member shapes are still diseemshle in FiCi 6 even, though the overall pxrrfhehas bee« greatly reduced forruxv in. The benefit of minimMiig damage to the device 2¾ is clearly understood Ironi a comparison of litesc MGS. Application of heat .from whatever sotitoe results in HG. 7 of .a tevmim. to the MG, 5 shape. Tie fact that there is some distortion at. the ends 46 reflects that the wellbore 16 may not let each shape fully extend to. its original dimension thus ioxcing some: of the ends and preferably all the ends 46 into.some degree of deformation indicative that the annulus 22 has been -Spanned' by a shape memory material arid that a gas migration seal is in place against the tubular island: the borehole 1-6.

[@023] FIGS. 1.6-18 are ait alternative embodirrierit to FIGS, 5-7 with the difference being the addition of a cover of a.: swelling material 4S on the shapes 44 and Stefr ends 46, Another layer of a «welling: material 47 can.'be placed between die iiikriar IS and the hub 42, Bveti With the addition of the swelling material 47 thfe hub 42 can Still be affixed to the tabular li: with fasteners or by welding. The, swelling material. 4S .and 47 can be eoatiiiuoos m wholly envelop the shape illustrated or it. can be segmental arid applied in IqcaiiMs where it willhave she most impact such as at: the fends 46 er as one or more rings up against the'tubular IS. As before, the origiHal position of BIG, 16 is altered with temperatuie above the trarisition point arid coriprission followed by mmoval of heat while maintaining com press ton tø hold the shape of FIG. 17 for a le w profile for 'running In. When machitig the desired location as shown in FIG. 1:8 heat frorii well fluids: ori'and another siMuIus such as impact dr beading will'cause te;gas migrationbarrier tø revert .to the 'FIG. 16 shape with some distortion as riiown in MG: 19 against die borehole wall 16 as ilie shape retains, compressive stress: doe to contact with.· the tubular J.g aod fie boréhblé wail 16. The well fluids or added' fluids: will also cause die swelling material such as rubber to chaiige shape or volume both: at the tubular 18 apd the wellbfori: wall M io compensate for my tendency\of the cement to pell'·away as,it .forireks.slightly· wiren setting up. Other swelling materials that swell in the presence of hydrocarbons or water are also coftteihpkted. 19034] FIG. 8 illustrates the use of :a stack of rings or a coiled spring -48:in an initial: coafigiiiation rising a shape memory material and Hø. 9 is the lower profile efotfigurarion for run m that is obtained, with compression at above the transition temperature so that an. annular cylindrical shape is ohiusaeG Eehtoval of heat with the expression force sjiU applied will result in retention of foe FIG. 9 shape until heal is applied; from whatever source and the device 20 is at foe proper location. At that time the shape will revert tø the MG. 8 shape but the .rings 48 will likely not fully assume: the original FIG. 8 shape. IX is preferred that some defonmiikm of the rings, or coil 48 take place so that foe shape or shapes can be in compression to form a gas migratioa sea! oral least ao impeding structure in the cemented aretulns in which the rings or coil 48 are disposed, wm FIG. 10 is a variation eh FIG, % in that: the rings or coil 511 are a composite streeture with a shape memory alley ifoenraljy at, SI and a shape: memory polymær orefoe outside at 54. As before the FIG. 11 position is foe low profile position for rein in ami the FIG, 1% position is affef heat is. applied at the desired location in ibe borehole 16. Hole: foal the alloy creates foe compressive strength on reversion .of shape- into contact: with the wellbore. On. foe other .hand: the: polymer & qii reversion to ward the original shape of FIG. 10 so that it acts as a scaling material that is more readily1 spread by tire compressive stress created by foe alloy core S2, While a hollow center 56 is "used, to reduce the required energy Si force the initial shape change: and: tø facilitate foe .reversion tø the .original shape, a solid center 56 is: also .envisioned.

[0038] HGS : 33-15 sho w afio&er variation of an ini d al angular shape 58 that is secured at :to the tabular IB and has a eåsdieve-ted free end 62 spaced from the tabular 18,. AiteriMiyely, the {foe eM:&2 cJm be secured to the tubular 18. As beforo the transition temperaturs;· is crossed with application d? •o?mpressive force to. attain the annoim cylinder shape of MC>. 14 followed by heat removal while. maintaining. foe compressive foice: so that foe M. 14 shape & obtained. In ik wdis® 1:€ where heat. & added ίο: foe shape to get the shape above foe transition temperature, foe result is that the bent porti on ¢4 péBetftites foe wellbore 16 thereby providing a. gas migration seal to foe ceiaent 24 by· spanning from, tire tubular M to foe wellbore wall 16 while displacing: foe cemnni.:24 from die contact location, with foe wellbore 16. POST] Those skilled in. the art will appreciate: that foe present invents on in its various sfobodinienis allows for a low profile for rim in so foaf foe gas migration device i s not likely to be damaged and ass ability to change sh ape and/or volume to spaa an annular cemented space before the cement sets so that it can: fonctfon to slow down or ©Himaate gas tnigrotion. The fact that the cement shrinks when sotting is not a factor in the operation of foe device that spans foe annular gap despite .foe presence; of cement While a. shape rnempty alloy is profeired the entire device can be a composite of different alloys with stages: transition temperatures so that portions of foe device can. deploy ίο a predetenuinCd sequence so as to more eifectively push the cement; out of the way before contact with foe fomiaiiph is initiated Tire device can also act as a piston to apply a compressive force to the cement to pash some of :foe: ceméM into foe borehole Wall in formations with fiactutos or apertures aad at the same time: to haye foe device spaa tire annular space so that gas migration can also be retarded or halted by foe device; While vrtiaiicms of foe. device mb shown in foe drawings io a single location, multiple ioeatfons are contemplated At each fixation, fog- design can be a single shape initially or a plurality of adjacent shapes that can be compressed Into a. single shape when above the transition, temperature to get the desired low profile shape. Gorabingtions of alloys and polymers or alloys and foams are contemplated to: take advantage· of foe compressive force that an alloy can ornate when

Iraosiiiorang back to an obgisal shape .aaid the ipolymer thai gets safter as. revetting ίο an original shape so that if can edhmice the sealing eapaMIty at: ilio borehole wall. Mtexnaiiyely, -sharp angles such as M BIOS. 005 can he used ϊβ either a cantilevered design or arse supported at mtahiple locations to: *:e iiiholar sining.

[§§3SJ The above description is illiistratiye of. the preferred embodiment and many modilicatiom may fee made by those s&ilfed in the. m without departing from the invention wtee scope is to be deierramed fi'ofn the literal and .equivalent scope of the claims below.