I-Downhole Chemical Injection Lines-Kungani Ihluleka?Okuhlangenwe nakho, Izinselele kanye Nokusetshenziswa Kwezindlela Ezintsha Zokuhlola
Copyright 2012, Society of Petroleum Engineers
Abstract
I-Statoil isebenzisa izinkambu ezimbalwa lapho kufakwa khona umjovo we-downhole we-scale inhibitor.Inhloso ukuvikela ishubhu engaphezulu kanye nevalvu yokuphepha ku(Ba/Sr) SO4orCaCO;isikali, ezimeni lapho ukuminya kwesikali kungase kube nzima futhi kubiza ukwenza njalo, isb. ukuhlanganisa izinkambu ezingaphansi kolwandle.
Umjovo oqhubekayo we-scale inhibitor downhole yisixazululo esifanelekile ngokobuchwepheshe sokuvikela ishubhu ephezulu kanye nevalvu yokuphepha emithonjeni enamandla okukalwa ngaphezu kwepaki yokukhiqiza;ikakhulukazi emithonjeni engadingi ukumpintsha njalo ngenxa yokukhula kwamandla endaweni eseduze yomthombo.
Ukuklama, ukusebenzisa nokugcina imigqa yokujova amakhemikhali kufuna ukugxila okwengeziwe ekukhetheni impahla, ukufaneleka kwamakhemikhali kanye nokuqapha.Ingcindezi, izinga lokushisa, izimiso zokugeleza kanye nejiyomethri yesistimu ingase yethule izinselele ekusebenzeni okuphephile.Izinselelo zihlonziwe emijoweni emide engamakhilomitha amaningana ukusuka endaweni yokukhiqiza ukuya esifanekisweni esingaphansi kolwandle kanye namavalvu omjovo phansi emithonjeni.
Okuhlangenwe nakho kwasensimini okubonisa ubunkimbinkimbi besistimu yomjovo oqhubekayo ophathelene nemvula kanye nezinkinga zokugqwala kuxoxwa ngazo.Izifundo zaselabhorethri kanye nokusetshenziswa kwezindlela ezintsha zokuthola iziqu zamakhemikhali a zimelelwe.Izidingo zezenzo zemikhakha eminingi ziyabhekwa.
Isingeniso
I-Statoil isebenzisa izinkambu ezimbalwa lapho umjovo oqhubekayo wamakhemikhali usetshenziswe khona.Lokhu ikakhulukazi kuhilela umjovo we-scale inhibitor(SI) lapho inhloso kuwukuvikela ishubhu engaphezulu kanye nevalvu yokuphepha ye-downhole (DHSV) ku-(Ba/Sr) SO4orCaCO;isikali.Kwezinye izimo i-emulsion breaker ijovwa emgodini ukuze kuqale inqubo yokuhlukanisa ijule emthonjeni ngokusemandleni ezingeni lokushisa eliphezulu.
Umjovo oqhubekayo we-scale inhibitor downhole yisixazululo esifanelekile ngokobuchwepheshe ukuvikela ingxenye engaphezulu yemithombo enamandla okukalwa ngaphezu kwepaki yokukhiqiza.Umjovo oqhubekayo ungase utuswe ikakhulukazi emithonjeni engadingi ukukhanywa ngenxa yokungabi namandla okukala emthonjeni oseduze;noma ezimeni lapho ukuminya kwesikali kungase kube nzima futhi kubiza ukwenza njalo, isb. ukuhlanganisa izinkambu ezingaphansi kolwandle.
I-Statoil inokuhlangenwe nakho okunwetshiwe kokujova amakhemikhali okuqhubekayo kumasistimu e-topside nezifanekiso ezingaphansi kolwandle kodwa inselele entsha iwukuyisa indawo yokujova ijule emthonjeni.Ukuklama, ukusebenzisa nokugcina imigqa yokujova amakhemikhali kudinga ukugxila okwengeziwe ezihlokweni ezimbalwa;njengokukhethwa kwezinto ezibonakalayo, ukufaneleka kwamakhemikhali nokuqapha.Ingcindezi, izinga lokushisa, izimiso zokugeleza kanye nejiyomethri yesistimu ingase yethule izinselele ekusebenzeni okuphephile.Izinselelo ngemigqa yokujova emide (amakhilomitha amaningana) ukusuka endaweni yokukhiqiza ukuya esifanekisweni esingaphansi kolwandle kanye namavalvu omjovo phansi emithonjeni kukhonjiwe;Fig.1.Ezinye zezinhlelo zokujova zisebenze ngokohlelo, kanti ezinye zehlulekile ngenxa yezizathu ezahlukene.Kuhlelelwe ukuthuthukiswa kwenkambu okusha okuningana komjovo wamakhemikhali we-downhole (DHCI);nokho;kwezinye izimo imishini ibingakafaneleki ngokugcwele.
Ukusetshenziswa kwe-DHCI kuwumsebenzi onzima.Kubandakanya ukuqedwa kanye nemiklamo yemithombo, ikhemistri yemithombo, isistimu ye-topside kanye nesistimu yomthamo wamakhemikhali wenqubo ye-topside.Ikhemikhali izophonswa isuka phezulu ngomugqa womjovo wamakhemikhali iye empahleni yokuqedela bese ishona phansi emthonjeni.Ngakho-ke, ekuhleleni nasekwenzeni lolu hlobo lokubambisana kwephrojekthi phakathi kwemikhakha eminingana kubalulekile.Ukucatshangelwa okuhlukahlukene kufanele kuhlolwe futhi ukuxhumana okuhle ngesikhathi sokuklama kubalulekile.Onjiniyela bezinqubo, onjiniyela be-subsea kanye nonjiniyela bokuphothula bayabandakanyeka, babhekana nezihloko zekhemistri yemithombo, ukukhethwa kwezinto ezibonakalayo, ukuqinisekiswa kokugeleza kanye nokuphathwa kwamakhemikhali okukhiqiza.Izinselele kungaba inkosi yesibhamu samakhemikhali noma ukuzinza kwezinga lokushisa, ukugqwala futhi kwezinye izimo umphumela we-vacuum ngenxa yengcindezi yendawo kanye nemiphumela yokugeleza emugqeni womjovo wamakhemikhali.Ngaphezu kwalezi, izimo ezifana nokucindezela okukhulu, izinga lokushisa eliphezulu, izinga eliphezulu legesi, amandla okukala aphezulu,Ibanga elide lenkaba kanye nendawo yomjovo ejulile emthonjeni, nikeza izinselelo zobuchwepheshe ezahlukene kanye nezidingo ekhemikhali elijovwe kanye nevalvu yomjovo.
Uhlolojikelele lwezinhlelo ze-DHCI ezifakwe ekusebenzeni kwe-Statoil kukhombisa ukuthi ulwazi aluzange luphumelele ngaso sonke isikhathi Ithebula 1. Kodwa-ke, ukuhlelwa kokwenziwa ngcono komklamo womjovo, ukufaneleka kwamakhemikhali, ukusebenza nokunakekelwa kuyenziwa.Izinselele ziyahlukahluka ensimini nenkundla, futhi inkinga akukhona ukuthi i-valve yomjovo wamakhemikhali ngokwayo ayisebenzi.
Eminyakeni edlule kuye kwaba nezinselelo ezimbalwa eziphathelene nemigqa yokujova amakhemikhali e-downhole.Kuleli phepha kunikezwe izibonelo ezithile kulokhu okuhlangenwe nakho.Leli phepha lixoxa ngezinselele nezinyathelo ezithathiwe ukuxazulula izinkinga ezihlobene nemigqa ye-DHCI.Kunikezwe imilando yamacala amabili;omunye on corrosion futhi omunye phezu chemical gun king.Okuhlangenwe nakho kwasensimini okubonisa ubunkimbinkimbi besistimu yomjovo oqhubekayo ophathelene nemvula kanye nezinkinga zokugqwala kuxoxwa ngazo.
Izifundo zaselabhorethri kanye nokusetshenziswa kwezindlela ezintsha zokuthola iziqu zamakhemikhali nazo ziyabhekwa;indlela yokupompa amakhemikhali, amandla okukala nokuvimbela, ukusetshenziswa kwemishini eyinkimbinkimbi nokuthi ikhemikhali izoba nomthelela kanjani ohlelweni lwe-topside lapho ikhemikhali ikhiqizwa emuva.Imibandela yokwamukela ukusetshenziswa kwamakhemikhali ihilela izindaba zemvelo, ukusebenza kahle, umthamo wokugcina indawo engaphezulu, izinga lepompo, ukuthi iphampu ekhona ingasetshenziswa yini njll. Izincomo zobuchwepheshe kufanele zisekelwe ekuhambisaneni koketshezi nekhemistri, ukutholwa kwensalela, ukuhambisana kwezinto, ukwakheka kwenkaba engaphansi kolwandle, uhlelo lomthamo wamakhemikhali. nezinto zokwakha endaweni ezungezile yale migqa.Ikhemikhali ingase idinge ukuthi ivinjwe amanzi ukuze kuvinjelwe ukuxhunywa kolayini womjovo ekuhlaselweni kwegesi futhi ikhemikhali akufanele iqhwa ngesikhathi sokuthutha nokugcinwa.Eziqondisweni ezikhona zangaphakathi kukhona uhlu lokuhlola lapho amakhemikhali angasetshenziswa endaweni ngayinye ohlelweni Izakhiwo zomzimba ezifana ne-viscosity zibalulekile.Uhlelo lomjovo lungasho ibanga elingu-3-50km lomugqa wokugeleza kwe-umbilical subsea kanye ne-1-3km phansi emthonjeni.Ngakho, ukuzinza kwezinga lokushisa nakho kubalulekile.Ukuhlolwa kwemiphumela eyehlayo, isb ezindaweni zokuhluza kungase kudingeke ukuthi kucatshangelwe.
Izinhlelo zokujova amakhemikhali e-Downhole
Inzuzo yezindleko
Umjovo oqhubekayo we-scale inhibitor downhole ukuvikela i-DHS Vor ishubhu lokukhiqiza mhlawumbe kubiza ngempumelelo uma kuqhathaniswa nokukhama umthombo nge-scale inhibitor.Lolu hlelo lokusebenza lunciphisa amathuba okulimala okwakheka uma kuqhathaniswa nokwelashwa kokuminyanisa, lunciphisa amathuba ezinkinga zenqubo ngemva kokuminyaniswa kwesikali futhi lunikeze ithuba lokulawula izinga lomjovo wamakhemikhali ovela ohlelweni lomjovo we-topside.Uhlelo lomjovo lungase lusetshenziselwe ukujova amanye amakhemikhali ngokuqhubekayo awele phansi futhi ngalokho anganciphisa ezinye izinselele ezingase zenzeke lapho kwehla umfula.
Ucwaningo olunzulu lwenziwe lokuthuthukisa isu lokukala imigodi ye-Oseberg S noma inkambu.Ukukhathazeka okukhulu kwesilinganiso kwakuyi-CaCO;ukukala kushubhu eliphezulu kanye nokwehluleka kwe-DHSV okungenzeka.I-Oseberg S noma ukucatshangelwa kwesu lokuphatha isikali kuphethe ngokuthi esikhathini esiyiminyaka emithathu, i-DHCI ibe yisixazululo esingabizi kakhulu emithonjeni lapho imigqa yokujova amakhemikhali yayisebenza khona.Isici sezindleko esiyinhloko mayelana nendlela yokuncintisana yokuminyanisa isikali kwakuwuwoyela ohlehlisiwe kunezindleko zamakhemikhali/zokusebenza.Ekusetshenzisweni kwe-scale inhibitor ekukhuphuleni igesi, into eyinhloko ezindlekweni zamakhemikhali kwakuyizinga eliphezulu lokuphakamisa igesi eliholela ekugxiliseni okukhulu kwe-SI, njengoba ukugxila kwakufanele kulinganiswe nezinga lokuphakamisa igesi ukuze kugwenywe inkosi yesibhamu samakhemikhali.Emithonjeni emibili ku-Oseberg S noma eyayinemigqa esebenza kahle ye-DHC I, le nketho yakhethwa ukuvikela ama-DHS V ngokumelene ne-CaCO;ukukala.
Isistimu yomjovo eqhubekayo namavalvu
Izixazululo ezikhona zokuqeda kusetshenziswa amasistimu omjovo wamakhemikhali aqhubekayo abhekana nezinselele zokuvimbela ukuxhunywa kwemigqa ye-capillary.Ngokuvamile isistimu yomjovo iqukethe umugqa we-capillary, 1/4" noma 3/8" ngaphandle kwedayamitha (OD), exhunywe endaweni eninginingi, ephakelwa-futhi exhunywe kusiphanyeko seshubhu ohlangothini olungemuva lweshubhu.Umugqa we-capillary unamathiselwe kububanzi obungaphandle beshubhu lokukhiqiza ngama-clamps akhethekile we-tubing collar futhi ugijimela ngaphandle kweshubhu kuze kufike phansi ku-mandrel umjovo wamakhemikhali.I-mandrel ngokwesiko ibekwe phezulu-umfudlana we-DHS V noma ujule emthonjeni ngenhloso yokunikeza amakhemikhali ajovwe isikhathi esanele sokuhlakazeka futhi abeke amakhemikhali lapho kutholakala khona izinselele.
Ku-valve yomjovo wamakhemikhali, i-Fig.2, i-cartridge encane engaba ngu-1.5" ububanzi iqukethe ama-valve okuhlola avimbela uketshezi lwe-wellbore ukuthi lungene emgqeni we-capillary.Kumane nje kuyi-poppet encane egibele isiphethu.Amandla entwasahlobo asetha futhi abikezele ingcindezi edingekayo ukuze uvule i-poppet esihlalweni sokuvala.Lapho ikhemikhali iqala ukugeleza, i-poppet iyaphakanyiswa esihlalweni sayo futhi ivule i-valve yokuhlola.
Kudingeka ukuthi kufakwe ama-valve okuhlola amabili.I-valve eyodwa iyisithiyo esiyinhloko esivimbela uketshezi lwe-wellbore ukuthi lungene emgqeni we-capillary.Lokhu kunokucindezela okuphansi kokuvula (ama-2-15bars) .Uma ingcindezi ye-hydrostatic ngaphakathi komugqa we-capillary ingaphansi kokucindezela komthombo, uketshezi lomthombo luzozama ukungena emgqeni we-capillary.Enye i-valve yokuhlola inokucindezela kokuvula okungavamile kwamabha angu-130-250 futhi yaziwa ngokuthi uhlelo lokuvimbela i-U-tube.Le valve ivimbela ikhemikhali engaphakathi komugqa we-capillary ukuthi igeleze ngokukhululekile emthonjeni uma umfutho we-hydrostatic ngaphakathi komugqa we-capillary uba mkhulu kunokucindezela komthombo endaweni yomjovo wamakhemikhali ngaphakathi kweshubhu lokukhiqiza.
Ngaphezu kwamavalvu okuhlola amabili, kuvame ukuba nesihlungi esisemgqeni, inhloso yalokhu ukuqinisekisa ukuthi azikho izinsalela zanoma yiluphi uhlobo ezingabeka engcupheni amandla okuvala amasistimu ama-valve okuhlola.
Amasayizi ama-valve okuhlola achaziwe mancane, futhi ukuhlanzeka koketshezi olujovwe kubalulekile ekusebenzeni kwawo.Kukholelwa ukuthi imfucumfucu ohlelweni ingasuswa ngokukhulisa ukugeleza ngaphakathi komugqa we-capillary, ukuze ama-valve okuhlola avuleke ngamabomu.
Lapho i-valve yokuhlola ivula, ingcindezi egelezayo iyancipha ngokushesha futhi isakaze umugqa we-capillary kuze kube yilapho ukucindezela futhi kwanda.I-valve yokuhlola izobe isivala kuze kube yilapho ukugeleza kwamakhemikhali kwakha ingcindezi eyanele yokuvula i-valve;umphumela uba i-oscillations yokucindezela ohlelweni lwe-valve yokuhlola.Ukucindezela okuphezulu kokuvula uhlelo lwe-valve yokuhlola, indawo encane yokugeleza iyasungulwa lapho i-valve yokuhlola ivula futhi uhlelo luzama ukufeza izimo zokulingana.
Amavalvu omjovo wamakhemikhali anomfutho wokuvula ophansi uma kuqhathaniswa;futhi uma umfutho weshubhu endaweni yokungena amakhemikhali uba ngaphansi kwesamba sokucindezela kwe-hydrostatic kwamakhemikhali ngaphakathi komugqa we-capillary kanye nokucindezela kokuvula ivalvu yokuhlola, eduze ne-vacuum noma i-vacuum engxenyeni engenhla yomugqa we-capillary.Uma umjovo wamakhemikhali uyeka noma ukugeleza kwamakhemikhali kuphansi, izimo eziseduze ne-vacuum zizoqala ukwenzeka engxenyeni ephezulu yomugqa we-capillary.
Izinga le-vacuum lincike ekucindezelweni komthombo, amandla adonsela phansi athile engxube yamakhemikhali ejovwe esetshenziswa ngaphakathi komugqa we-capillary, ingcindezi yokuvula ivalvu yokuhlola endaweni yomjovo kanye nokugeleza kwekhemikhali ngaphakathi komugqa we-capillary.Izimo zemithombo zizohluka ngesikhathi sokuphila kwensimu futhi amandla okukhipha i-vacuum ngakho-ke azohluka isikhathi esengeziwe.Kubalulekile ukuqaphela lesi simo ukuze ucabangele kahle futhi uqikelele ngaphambi kokuba kuvele izinselelo ezilindelekile.
Kanye namazinga aphansi omjovo, ngokuvamile izincibilikisi ezisetshenziswa kulezi zinhlobo zezinhlelo zokusebenza ziyahwamuka imiphumela ebangelayo engakahlolisiswa ngokugcwele.Le miphumela iyinkosi yezibhamu noma imvula yezinto eziqinile, isibonelo ama-polymers, lapho i-solvent ihwamuka.
Ngaphezu kwalokho, amangqamuzana e-galvanic angakhiwa esigabeni soshintsho phakathi kwendawo ewuketshezi yekhemikhali kanye nomhwamuko ogcwaliswe eduze nesigaba segesi ye-vacuum ngenhla.Lokhu kungaholela ekugqwaleni kwemigodi yendawo ngaphakathi komugqa we-capillary ngenxa yokwanda kolaka lwamakhemikhali ngaphansi kwalezi zimo.Ama-flakes noma amakristalu kasawoti akheke njengefilimu ngaphakathi komugqa we-capillary njengoba ingaphakathi lawo loma lingase ligxumeke noma livale umugqa we-capillary.
Well barrier ifilosofi
Lapho iklama izixazululo zemithombo eqinile, i-Statoil idinga ukuthi ukuphepha komthombo kube khona ngaso sonke isikhathi phakathi nomjikelezo wokuphila womthombo.Ngakho, i-Statoil idinga ukuthi kube nezithiyo ezimbili ezimele zemithombo ezingaguquki.Umdwebo 3 ubonisa uhlelo lwesithiyo somthombo ongavamile, lapho umbala oluhlaza okwesibhakabhaka umele imvilophu eyinhloko yokuvimbela umthombo;kulokhu ishubhu lokukhiqiza.Umbala obomvu umele imvilophu yesibili yokuvimbela;isikhwama.Ohlangothini lwesokunxele emdwebeni umjovo wekhemikhali ukhonjiswe njengomugqa omnyama onephuzu lomjovo eshubhuni lokukhiqiza endaweni ephawulwe ngokubomvu (umgoqo wesibili).Ngokwethula izinhlelo zokujova ngamakhemikhali emthonjeni, zombili izithiyo zomthombo oyinhloko kanye nezesibili zisengozini.
Umlando wecala ngokugqwala
Ukulandelana kwezehlakalo
Umjovo wamakhemikhali we-Downhole we-scale inhibitor usetshenziswe endaweni kawoyela esetshenziswa yi-Statoil ku-Norwegian Continental Shelf.Kulokhu i-scale inhibitor esetshenzisiwe yayikade ifanelekele ukusetshenziswa kwe-topside ne-subsea.Ukuqedwa kabusha komthombo kwalandelwa ukufakwa kwe-DHCIpointat2446mMD, Fig.3.Umjovo we-downhole we-topside scale inhibitor waqalwa ngaphandle kokuhlolwa okwengeziwe kwekhemikhali.
Ngemva konyaka owodwa wokusebenza ukuvuza ohlelweni lomjovo wamakhemikhali kwabonwa futhi kwaqalwa uphenyo.Ukuvuza kube nomthelela omubi emigomeni yemithombo.Izigameko ezifuze lezi zenzeke emithonjeni eminingi kanti eminye yayo kudingeke ukuthi ivalwe ngesikhathi uphenyo lusaqhubeka.
Ishubhu yokukhiqiza yadonswa futhi yafundwa ngokuningiliziwe.Ukuhlasela kokugqwala kwakulinganiselwe ohlangothini olulodwa lweshubhu, futhi amanye amalunga amashubhu agqwalile kangangokuthi empeleni kwaba nezimbobo kuwo.Insimbi ye-chrome elinganiselwa ku-8.5mm enogqinsi engu-3% yayihlakazekile esikhathini esingaphansi kwezinyanga eziyi-8.Ukugqwala okukhulu kwenzeke engxenyeni ephezulu yomthombo, kusukela emthonjeni kwehle kuya cishe ku-380m MD, futhi amajoyinti amashubhu agqwalile kakhulu atholakala cishe cishe ku-350m MD.Ngaphansi kwalokhu kujula kubonwe ukugqwala okuncane noma okungekho nhlobo, kodwa kutholwe imfucumfucu eminingi kuma-OD's amashubhu.
I-9-5 / 8'' casing nayo yasikwa futhi yadonsa futhi imiphumela efanayo yabonwa;ngokugqwala engxenyeni engenhla yomthombo ohlangothini olulodwa kuphela.Ukuvuza okudaliwe kudalwe ukuqhuma kwengxenye ebuthaka ye-casing.
Izinto zomugqa womjovo wamakhemikhali kwakuyi-Alloy 825.
Ukufaneleka kwamakhemikhali
Izakhiwo zamakhemikhali nokuhlolwa kokugqwala kubalulekile ekugxilweni kwe-scale inhibitor futhi isikali sangempela se-scale inhibitor sase sifanelekile futhi sisetshenziswa ekufakweni kwe-topside ne-subsea iminyaka eminingana.Isizathu sokusebenzisa imbobo yangempela yamakhemikhali kwaba ngcono izindawo zemvelo ngokufaka ikhemikhali ekhona ye-downhole Kodwa-ke, i-scale inhibitor yayisetshenziswe kuphela endaweni engaphansi nendawo emazingeni okushisa olwandle (4-20℃).Lapho ijova emthonjeni izinga lokushisa lekhemikhali lingaba phezulu lifike ku-90℃, kodwa akukho okunye ukuhlola okwenziwe ngalelizinga lokushisa.
Ukuhlolwa kokuqala kokubola kwenziwa umphakeli wamakhemikhali futhi imiphumela yabonisa u-2-4mm/ngonyaka we-carbon steel ezingeni lokushisa eliphezulu.Phakathi nalesi sigaba kube nokubandakanyeka okuncane kwekhono lobuchwepheshe lomsebenzi womqhubi.Ukuhlola okusha kamuva kwenziwa opharetha okubonisa ukuthi i-scale inhibitor igqwalile kakhulu ezintweni ezikumashubhu okukhiqiza kanye ne-casing yokukhiqiza, amazinga okugqwala angaphezu kuka-70mm/ngonyaka.I-chemical injection line material I-Alloy 825 ayizange ihlolwe ngokumelene ne-scale inhibitor ngaphambi komjovo.Izinga lokushisa lomthombo lingase lifinyelele ku-90℃ futhi ukuhlolwa okwanele kufanele ngabe kwenziwa ngaphansi kwalezi zimo.
Uphenyo luphinde lwembula ukuthi i-scale inhibitor njengesixazululo esigxilile ibike i-pH ye-<3.0.Nokho, i-pH ayizange ikalwe.Kamuva i-pH elinganisiwe yabonisa inani eliphansi kakhulu le-pH 0-1.Lokhu kukhombisa isidingo sezilinganiso nokucatshangelwa kwezinto ezibonakalayo ngaphezu kwamanani e-pH anikeziwe.
Ukuhunyushwa kwemiphumela
Umugqa womjovo (Fig.3) wakhiwe ukunikeza ingcindezi ye-hydrostatic ye-scale inhibitor edlula ukucindezela kahle endaweni yomjovo.I-inhibitor ijova ngengcindezi ephakeme kunaleyo ekhona emgodini womthombo.Lokhu kubangela umphumela we-U-tube lapho kuvalwe umthombo.I-valve izohlala ivuleka ngengcindezi ephakeme emgqeni womjovo kunasemthonjeni.Ngakho-ke kungenzeka ukuthi kuvame noma ukuhwamuka emgqeni womjovo.Izinga lokugqwala kanye nengcuphe yokufaka imigodi inkulu kakhulu endaweni yenguquko yegesi/uketshezi ngenxa yokuhwamuka kwento encibilikayo.Ukuhlolwa kwaselabhorethri okwenziwe kumakhuphoni kwaqinisekisa le mbono.Emithonjeni lapho kuvuza khona, zonke izimbobo emigqeni yomjovo zazitholakala engxenyeni engenhla yomugqa womjovo wamakhemikhali.
Umdwebo 4 ubonisa ukuthwebula izithombe komugqa we-DHC I nokugqwala okubalulekile komgodi.Ukugqwala okubonwe kushubhu lokukhiqiza kwangaphandle kubonise ukuchayeka kwasendaweni kwe-scale inhibitor kusukela endaweni yokuvuza komgodi.Ukuvuza kubangelwe ukugqwala komgodi ngamakhemikhali agqwala kakhulu kanye nokuvuza ngomugqa womjovo wamakhemikhali ku-casing yokukhiqiza.I-scale inhibitor yafuthwa kusukela kulayini we-capillary ogobile ukuya ku-casing kanye namashubhu futhi kwavuza.Noma yimiphi imiphumela yesibili yokuvuza emugqeni womjovo ayizange icatshangelwe.Kwafinyelelwa esiphethweni sokuthi ukugqwala kwe-casing-and tubing kwakuwumphumela we-concentrated scale inhibitors ethandazwa kusukela kumugqa we-capillary ogobile ukuya ku-casing kanye neshubhu, Fig.5.
Kulokhu kube nokuntuleka kokubandakanyeka konjiniyela bezinto ezibonakalayo.Ukubola kwamakhemikhali kulayini we-DHCI akuzange kuhlolwe futhi imiphumela yesibili ngenxa yokuvuza ayizange ihlolwe;njengokuthi izinto ezizungezile zingakubekezelela yini ukuchayeka kwamakhemikhali.
Umlando wecala lenkosi yesibhamu samakhemikhali
Ukulandelana kwezehlakalo
Isu lokuvimbela isikali lenkambu ye-HP HT bekuwumjovo oqhubekayo we-scale inhibitor ukhuphuka nomfula ivalvu yokuphepha ye-downhole.Amandla amakhulu okukala i-calcium carbonate akhonjwe emthonjeni.Enye yezinselelo kwaba izinga lokushisa eliphezulu kanye negesi ephezulu kanye namazinga okukhiqiza ama-condensate ahlanganiswe nezinga eliphansi lokukhiqiza amanzi.Ukukhathazeka ngokujova i-scale inhibitor kwakuwukuthi i-solvent izosuswa izinga eliphezulu lokukhiqiza igesi futhi inkosi yesibhamu yamakhemikhali yayizokwenzeka endaweni yomjovo enhla nomfula we-valve yokuphepha emthonjeni, Fig.1.
Ngesikhathi sokufaneleka kwe-scale inhibitor kwagxilwa ekusebenzeni kahle komkhiqizo ezimeni ze-HP HT okuhlanganisa nokuziphatha ohlelweni lwenqubo ye-topside (izinga lokushisa eliphansi).Ukuna kwe-scale inhibitor ngokwayo kushubhu lokukhiqiza ngenxa yezinga eliphezulu legesi yikona okwakukhathaza kakhulu.Ukuhlolwa kwaselabhorethri kubonise ukuthi i-scale inhibitor ingase ihle futhi inamathele odongeni lweshubhu.Ngakho-ke ukusebenza kwe-valve yokuphepha kungase kunqobe ingozi.
Okuhlangenwe nakho kwabonisa ukuthi ngemva kwamasonto ambalwa lokusebenza ulayini wamakhemikhali wawuvuza.Kwakungenzeka ukuqapha ukucindezela kwe-wellbore esilinganisweni esiphezulu esifakwe emgqeni we-capillary.Umugqa wahlukaniswa ukuze uthole ubuqotho obuhle.
Ulayini womjovo wamakhemikhali wakhishwa emthonjeni, wavulwa futhi wahlolwa ukuze kuhlonzwe inkinga futhi kutholwe okungenzeka kube nezizathu zokwehluleka.Njengoba kungabonwa ku-Fig.6, inani elibalulekile lemvula litholakele futhi ukuhlaziywa kwamakhemikhali kubonisa ukuthi okunye kwalokhu kwakuyi-scale inhibitor.Imvula yayitholakala ku-seal futhi i-poppet ne-valve ayikwazanga ukusebenza.
Ukwehluleka kwe-valve kubangelwe udoti ngaphakathi kwesistimu ye-valve evimbela ama-valve okuhlola ukudla esihlalweni sensimbi ukuya kwesensimbi.Imfucumfucu yahlolisiswa futhi izinhlayiya eziyinhloko zafakazelwa ukuthi ziyi-metal shavings, cishe ezikhiqizwa ngesikhathi sokufakwa kwe-capillary line.Ukwengeza, ezinye izinsalela ezimhlophe zabonakala kuwo womabili ama-valve okuhlola ikakhulukazi ngemuva kwama-valve.Lolu uhlangothi lwengcindezi ephansi, okungukuthi uhlangothi luhlala luthintana noketshezi lomthombo.Ekuqaleni, lokhu kukholakala ukuthi udoti ophuma emthonjeni wokukhiqiza njengoba amavalvu ayevaleleke evulekile futhi echayeke oketshezini lomthombo.Kodwa ukuhlola imfucumfucu kubonakale kungama-polymer anamakhemikhali afanayo namakhemikhali asetshenziswa njenge-scale inhibitor.Lokhu kwabamba isithakazelo sethu futhi i-Statoil yafuna ukuhlola izizathu ezibangela le mfucumfucu ye-polymer ekhona kulayini we-capillary.
Ukufaneleka kwamakhemikhali
Emkhakheni we-HP HT kunezinselelo eziningi mayelana nokukhethwa kwamakhemikhali afanelekile ukuze kuncishiswe izinkinga ezihlukahlukene zokukhiqiza.Esilinganisweni se-scale inhibitor yomjovo oqhubekayo wokujova phansi, kwenziwa lezi zivivinyo ezilandelayo:
● Ukuzinza komkhiqizo
● Ukuguga okushisayo
● Ukuhlolwa kokusebenza okunamandla
● Ukuhambisana ne-formation water and hydrate inhibitor (MEG)
● Ukuhlolwa kwenkosi yesibhamu emile futhi eshukumisayo
● Ulwazi lokuchithwa kabusha kwamanzi, amakhemikhali amasha kanye ne-MEG
Ikhemikhali izojovwa ngesilinganiso somthamo esinqunyiwe,kodwa ukukhiqizwa kwamanzi ngeke kuhlale njalo,ie amanzi slugging.Phakathi kwama-slugs amanzi,lapho ikhemikhali ingena emthonjeni,izohlangatshezwa yi hot,umfudlana ogelezayo wegesi ye-hydrocarbon.Lokhu kufana nokujova i-scale inhibitor ekuphakanyisweni kwegesi(Fleming etal.2003) .Kanye
izinga lokushisa eliphezulu legesi,ingozi yokukhumula i-solvent iphezulu kakhulu futhi inkosi yesibhamu ingase ibangele ukuvinjelwa kwevalvu yomjovo.Lokhu kuyingozi ngisho nakumakhemikhali akhiwe anephuzu eliphezulu lokubilayo/izincibilikisi zokucindezela komhwamuko ophansi kanye namanye ama-Vapor Pressure Depressure(VPD's) .Uma kwenzeka ukuvaleka kancane,ukugeleza kwamanzi okwakheka,I-MEG kanye/noma ikhemikhali entsha kufanele ikwazi ukususa noma ukuphinda incibilikise ikhemikhali ephelelwe amanzi noma ekhishwe isibhamu.
Kulokhu umshini wokuhlola welabhorethri inoveli yakhelwe ukuphindaphinda izimo ezigelezayo eduze nezimbobo zomjovo ku-HP/HTg njengohlelo lokukhiqiza.Imiphumela evela ekuhlolweni kwenkosi yesibhamu eshukumisayo ibonisa ukuthi ngaphansi kwezimo ezihlongozwayo zesicelo ukulahlekelwa okukhulu kwe-solvent kwabhalwa.Lokhu kungaholela enkosini yezibhamu ngokushesha futhi ekugcineni kuvinjwe imigqa egelezayo.Ngakho-ke umsebenzi wabonisa ukuthi kwakunengozi enkulu ngokuqhathaniswa yokujova amakhemikhali okuqhubekayo kule mithombo ngaphambi kokukhiqizwa kwamanzi futhi kwaholela esinqumweni sokulungisa izinqubo zokuqalisa ezivamile zalo mkhakha, ukubambezeleka komjovo wamakhemikhali kuze kube yilapho kutholwa ukuphumelela kwamanzi.
Ukufaneleka kwe-scale inhibitor yomjovo oqhubekayo womjovo ube nokugxila okuphezulu ekukhumulweni kwe-solvent kanye nenkosi yesibhamu ye-scale inhibitor endaweni yomjovo kanye naku-flowline kodwa amandla okuba inkosi yesibhamu kuvalvu yomjovo ngokwawo awazange ahlolwe.I-valve yomjovo cishe yehlulekile ngenxa yokulahlekelwa okukhulu kwe-solvent kanye nenkosi yesibhamu esisheshayo,Fig.6.Imiphumela ibonisa ukuthi kubalulekile ukuba nombono ophelele wesistimu;hhayi kuphela ukugxila ezinseleleni zokukhiqiza,kodwa futhi nezinselele ezihlobene nokujova ikhemikhali,okungukuthi i-valve yomjovo.
Umuzwa wezinye izinkambu
Omunye wemibiko yakuqala ngezinkinga zemigqa yokujova amakhemikhali ebangeni elide wawuvela kumkhakha wesathelayithi we-Gull fak sandVig dis (Osa etal.2001) .Imigqa yomjovo we-subsea yavinjelwa ekwakhekeni kwe-hydrate ngaphakathi komugqa ngenxa yokuhlasela kwegesi evela kuketshezi olukhiqizwayo. emgqeni ngevalvu yomjovo.Imihlahlandlela emisha yokwakhiwa kwamakhemikhali okukhiqizwa ngaphansi kolwandle yenziwa.Izimfuneko zazihlanganisa ukukhishwa kwezinhlayiyana(ukuhlunga) kanye nokwengezwa kwe-hydrate inhibitor (isb. i-glycol) kuwo wonke ama-scale inhibitors asekelwe emanzini azojovwa ezifanekisweni ezingaphansi kolwandle.Ukuzinza kwamakhemikhali,i-viscosity kanye nokuhambisana (uketshezi nezinto zokwakha) nazo zacatshangelwa.Lezi zidingo ziphinde zafakwa ohlelweni lwe-Statoil futhi zifaka umjovo wamakhemikhali we-downhole.
Ngesikhathi sokuthuthukiswa kwe-Oseberg S noma umkhakha kwanqunywa ukuthi yonke imithombo kufanele igcwaliswe ngezinhlelo ze-DHC I(Fleming etal.2006) .Inhloso bekuwukuvimbela i-CaCO;ukukala kushubhu eliphezulu ngomjovo we-SI.Enye yezinselelo ezinkulu maqondana nemigqa yokujova amakhemikhali kwakuwukuthola ukuxhumana phakathi kwendawo engaphansi nendawo yokukhipha amanzi.Ububanzi bangaphakathi bomugqa womjovo wamakhemikhali bunciphe ukusuka ku-7mm ukuya ku-0.7mm(ID) eduze kwevalvu yokuphepha ye-annulus ngenxa yokulinganiselwa kwesikhala kanye nekhono loketshezi oluzothuthwa ngalesi sigaba kube nomthelela ezingeni lempumelelo.Imithombo eminingi yesikhulumi yayinemigqa yomjovo wamakhemikhali eyayixhunywe,kodwa isizathu sasingaqondakali.Izitimela zoketshezi oluhlukahlukene (glycol,luhlaza,condensate,ixylene,isikali inhibitor,amanzi njll.) zahlolwa ilabhorethri ukubona i-viscosity nokuhambisana futhi zaphonswa ziye phambili futhi zabuyela emuva ukuze zivule imigqa.;nokho,i-target scale inhibitor ayikwazanga ukumpontshwa yonke indlela yehle iye kuvalvu yomjovo wamakhemikhali.Ngokuqhubekayo,izinkinga zibonakale ngokuwa kwe-phosphonate scale inhibitor kanye nensalela ye-CaCl z completion brine emthonjeni owodwa kanye nenkosi yesibhamu ye-scale inhibitor ngaphakathi komthombo onesilinganiso esiphezulu sikaphethiloli kanye nokusikwa kwamanzi aphansi(Fleming etal.2006)
Izifundo ezifundiwe
Ukuthuthukiswa kwendlela yokuhlola
Izifundo eziyinhloko ezitholwe ekuhlulekeni kwezinhlelo ze-DHC I beziphathelene nokusebenza kahle kobuchwepheshe be-scale inhibitor hhayi ngokuphathelene nokusebenza kanye nomjovo wamakhemikhali.Umjovo we-Topside kanye nomjovo we-subsea usebenze kahle isikhathi esengeziwe;nokho,isicelo selulelwe kumjovo wamakhemikhali we-downhole ngaphandle kokubuyekezwa okuhambisanayo kwezindlela zokufaneleka kwamakhemikhali.Ulwazi lwe-Statoil oluvela emacaleni amabili omkhakha owethuliwe ukuthi imibhalo elawulayo noma iziqondiso zokufaneleka kwamakhemikhali kufanele zibuyekezwe ukuze kufakwe lolu hlobo lokusetshenziswa kwamakhemikhali.Izinselelo ezimbili eziyinhloko zihlonzwe njenge-i) i-vacuum emugqeni womjovo wamakhemikhali kanye nee) nokuna kwekhemikhali okungaba khona.
Ukuhwamuka kwekhemikhali kungase kwenzeke kushubhu lokukhiqiza (njengoba kubonakala ku-gun king case) nakushubhu lomjovo (i-interface yesikhashana ikhonjwe ku-vacuum case) kunengozi yokuthi lezi zimvula zinganyakaziswa nokugeleza futhi. ku-valve yomjovo futhi uqhubeke ungene emthonjeni.Ivalve yomjovo ivamise ukuklanywa ngesihlungi esinyuka nomfula wephoyinti lomjovo,lokhu kuyinselele,njengoba esimweni sezulu lesi sihlungi singase sixhunywe kubangele ukuthi i-valve ihluleke.
Ukubhekwa neziphetho zokuqala ezivela ezifundweni ezifundiwe kuholele ocwaningweni olubanzi lwaselabhorethri mayelana nalesi sigameko.Inhloso yonke bekuwukusungula izindlela ezintsha zemfundo ukuze kugwenywe izinkinga ezifanayo esikhathini esizayo.Kulolu cwaningo kuye kwenziwa ukuhlolwa okuhlukahlukene futhi kwaklanywa izindlela ezimbalwa zaselabhorethri (zathuthukiswa ukuze) ukuhlola amakhemikhali maqondana nezinselele ezihlonziwe.
● Ukuvinjwa kokuhlunga nokuzinza komkhiqizo kumasistimu avaliwe.
● Umthelela wokulahlekelwa kwe-solvent engxenyeni yokubola kwamakhemikhali.
● Umthelela wokulahlekelwa kwe-solvent ingxenye ngaphakathi kwe-capillary ekwakhekeni kwezinto eziqinile noma amapulaki e-viscous.
Ngesikhathi sokuhlolwa kwezindlela zaselabhorethri kuye kwatholakala izinkinga ezingaba khona
● Ukuvinjwa kwesihlungi okuphindaphindiwe nokuzinza okubi.
● Ukwakheka kweziqina kulandela ukuhwamuka okuncane okuvela ku-capillary
● Izinguquko ze-PH ngenxa yokulahlekelwa kwe-solvent.
Imvelo yokuhlola okwenziwayo iphinde yanikeza ulwazi olwengeziwe nolwazi oluhlobene nezinguquko zezakhiwo zamakhemikhali ngaphakathi kwama-capillaries lapho engaphansi kwezimo ezithile.,nokuthi lokhu kwehluka kanjani ezixazululweni eziningi ezingaphansi kwezimo ezifanayo.Umsebenzi wokuhlola uphinde waveza umehluko omkhulu phakathi koketshezi oluningi,izigaba zomhwamuko noketshezi oluyinsalela olungaholela emandleni akhulayo emvula kanye/noma ukugqwala kokubola.
Inqubo yokuhlola ukubola kwe-scale inhibitors yathuthukiswa futhi yafakwa kumadokhumenti alawulayo.Kuhlelo lokusebenza ngalunye ukuhlolwa okunwetshiwe kokubola kwakufanele kwenziwe ngaphambi kokuthi kusetshenziswe isikali esivimbela ukubola.Ukuhlolwa kwe-gun king kwekhemikhali ekulayini womjovo kwenziwe futhi.
Ngaphambi kokuqala iziqu zekhemikhali kubalulekile ukwakha ububanzi bomsebenzi obuchaza izinselelo nenjongo yamakhemikhali.Esigabeni sokuqala kubalulekile ukukhomba izinselelo ezinkulu ukuze ukwazi ukukhetha izinhlobo zamakhemikhali azoxazulula inkinga.Isifinyezo semibandela yokwamukela ebaluleke kakhulu singatholakala kuThebula 2.
Ukufaneleka kwamakhemikhali
Ukufaneleka kwamakhemikhali kuqukethe kokubili ukuhlolwa nokuhlolwa kwethiyori kuhlelo ngalunye.Ukucaciswa kobuchwepheshe kanye nemibandela yokuhlola kufanele kuchazwe futhi kusungulwe,isibonelo ngaphakathi kwe-HSE,ukuhambisana kwezinto ezibonakalayo,ukuzinza komkhiqizo kanye nekhwalithi yomkhiqizo (izinhlayiya).Ngokuqhubekayo,indawo yokubanda,i-viscosity nokuhambisana namanye amakhemikhali,i-hydrate inhibitor,amanzi okwakhiwa kanye noketshezi olukhiqiziwe kufanele kunqunywe.Uhlu olwenziwe lula lwezindlela zokuhlola ezingase zisetshenziselwe ukufaneleka kwamakhemikhali lunikezwe kuThebula 2.
Ukugxila okuqhubekayo kanye nokuqapha ukusebenza kahle kwezobuchwepheshe,Amazinga omthamo kanye namaqiniso e-HSE abalulekile.Izidingo zomkhiqizo zingashintsha insimu noma inqubo yempilo yesitshalo;ziyahlukahluka ngamazinga okukhiqiza kanye nokwakheka koketshezi.Umsebenzi wokulandelela ngokuhlolwa kokusebenza,ukwenza kahle kanye/noma ukuhlolwa kwamakhemikhali amasha kufanele kwenziwe njalo ukuze kuqinisekiswe uhlelo oluphelele lokwelapha.
Kuya ngekhwalithi yamafutha,ukukhiqizwa kwamanzi kanye nezinselelo zobuchwepheshe embonini yokukhiqiza phesheya kwezilwandle,ukusetshenziswa kwamakhemikhali okukhiqiza kungase kudingeke ukuze kuzuzwe ikhwalithi yokuthekelisa,izidingo zokulawula,kanye nokusebenzisa ukufakwa kwe-offshore ngendlela ephephile.Zonke izinkambu zinezinselelo ezihlukene, futhi amakhemikhali okukhiqiza adingekayo azohluka ngokwezindawo kanye nesikhathi esengeziwe.
Kubalulekile ukugxila ekusebenzeni kahle kwezobuchwepheshe kwamakhemikhali okukhiqiza ohlelweni lweziqu,kodwa futhi kubaluleke kakhulu ukugxila ezintweni zamakhemikhali,njengokuzinza,izinga lomkhiqizo nokuhambisana.Ukuhambisana kulesi silungiselelo kusho ukuhambisana noketshezi,izinto zokwakha kanye namanye amakhemikhali okukhiqiza.Lokhu kungaba inselele.Akufiseleki ukusebenzisa ikhemikhali ukuxazulula inkinga ukuze uthole kamuva ukuthi ikhemikhali inomthelela noma idala izinselele ezintsha.Mhlawumbe izakhiwo zamakhemikhali hhayi inselele yobuchwepheshe okuyinselelo enkulu kakhulu.
Izidingo ezikhethekile
Izidingo ezikhethekile ekuhlungeni imikhiqizo enikeziwe kufanele zisetshenziswe ohlelweni olungaphansi kolwandle kanye nomjovo oqhubekayo wokujova phansi.Izihlungi kanye nezihlungi ohlelweni lomjovo wamakhemikhali kufanele zihlinzekwe ngokususelwa ekucacisweni kwempahla esetshenziswayo ephuma ngezansi ohlelweni lomjovo ongaphezulu.,amaphampu namavalvu omjovo,kuma-valve omjovo we-downhole.Lapho kusetshenziswa umjovo oqhubekayo wembobo wamakhemikhali ukucaciswa kwesistimu yomjovo wamakhemikhali kufanele kusekelwe kulokho okucaciswayo okubaluleke kakhulu.Lesi mhlawumbe isihlungi ku-valve yomjovo phansi.
Izinselele zokujova
Uhlelo lomjovo lungasho ibanga elingu-3-50km le-umbilical subsea flowline kanye ne-1-3km phansi emthonjeni.Izinto ezibonakalayo ezifana ne-viscosity kanye nekhono lokupompa amakhemikhali kubalulekile.Uma i-viscosity emazingeni okushisa olwandle iphezulu kakhulu kungaba inselele ukumpompa ikhemikhali ngomugqa womjovo wamakhemikhali kunkaba engaphansi kolwandle kanye nendawo yomjovo ongaphansi kolwandle noma emthonjeni.I-viscosity kufanele ihambisane nokucaciswa kwesistimu endaweni yokugcina okulindelekile noma izinga lokushisa lokusebenza.Lokhu kufanele kuhlolwe esimweni ngasinye,futhi izoncika ohlelweni.Njengoba izinga lomjovo wamakhemikhali etafuleni liyisici empumelelweni yomjovo wamakhemikhali.Ukunciphisa ingozi yokuxhuma ulayini womjovo wamakhemikhali,amakhemikhali akulesi simiso kufanele avinjelwe i-hydrate (uma engase abe nama-hydrates).Ukuhambisana noketshezi olukhona ohlelweni (uketshezi olulondolozayo) kanye ne-hydrate inhibitor kufanele kwenziwe.Ukuhlolwa kokuzinza kwekhemikhali emazingeni okushisa angempela (izinga lokushisa eliphansi kakhulu le-ambient,izinga lokushisa elizungezile,izinga lokushisa ngaphansi kolwandle,izinga lokushisa lomjovo) kufanele lidluliswe.
Uhlelo lokugeza imigqa yomjovo wamakhemikhali ngezikhathi ezithile kufanele lucatshangelwe.Kungase kunikeze umphumela wokuvimbela ukusula njalo umugqa womjovo wamakhemikhali nge-solvent,i-glycol noma ikhemikhali yokuhlanza ukuze kukhishwe imali engase ifakwe ngaphambi kokuba iqoqwe futhi ingabangela ukuxhuma komugqa.Isixazululo samakhemikhali esikhethiwe soketshezi olushaywayo kufanele sibeiyahambisana nekhemikhali ekulayini womjovo.
Kwezinye izimo ulayini womjovo wamakhemikhali usetshenziselwa ukusetshenziswa kwamakhemikhali okuningana okusekelwe ezinseleleni ezihlukene empilweni yonke kanye nezimo zoketshezi.Esigabeni sokuqala sokukhiqiza ngaphambi kokuphumelela kwamanzi izinselele ezinkulu zingahluka kulezo zasekupheleni kwesikhathi ngokuvamile ezihlobene nokwanda kokukhiqizwa kwamanzi.Ukushintsha kusuka ku-non-aqueous inhibitor based inhibitor njenge-asphalt ene inhibitor kuya kumakhemikhali asekelwe emanzini njenge-scale inhibitor kunganikeza izinselele ngokuhambisana.Ngakho-ke kubalulekile ukugxila ekusebenzisaneni nasekuqeqesheni nasekusetshenzisweni kwama-spacers uma kuhlelwa ukushintsha amakhemikhali emugqeni womjovo wamakhemikhali.
Izinto zokwakha
Mayelana nokuhambisana kwezinto,wonke amakhemikhali kufanele ahambisane nezimpawu,ama-elastomers,ama-gaskets nezinto zokwakha ezisetshenziswa ohlelweni lomjovo wamakhemikhali kanye nesikhungo sokukhiqiza.Inqubo yokuhlola ukubola kwamakhemikhali (isb. i-acidic scale inhibitor) yomjovo oqhubekayo womjovo kufanele yenziwe.Ngohlelo ngalunye ukuhlolwa kokubola okunwetshiwe kufanele kwenziwe ngaphambi kokuba kufakwe umjovo wamakhemikhali.
Ingxoxo
Izinzuzo kanye nobubi bomjovo wekhemikhali we-downhole oqhubekayo kufanele kuhlolwe.Umjovo oqhubekayo we-scale inhibitor ukuvikela i-DHS Vor ishubhu lokukhiqiza kuyindlela enhle yokuvikela umthombo esikalini.Njengoba kushiwo kuleli phepha kunezinselelo eziningana ngomjovo wamakhemikhali we-downhole oqhubekayo,nokho ukunciphisa ingozi kubalulekile ukuqonda izenzakalo ezixhunywe nesixazululo.
Enye indlela yokunciphisa ubungozi ukugxila ekuthuthukisweni kwendlela yokuhlola.Uma kuqhathaniswa nomjovo wamakhemikhali we-topside noma ngaphansi kolwandle kunezimo ezihlukene nezinzima kakhulu phansi emthonjeni.Inqubo yokufaneleka yamakhemikhali yokujova ngokuqhubekayo kwamakhemikhali emgodini kufanele icabangele lezi zinguquko ezimweni.Iziqu zamakhemikhali kufanele zenziwe ngokuya ngezinto amakhemikhali angase ahlangane nazo.Izidingo zokufaneleka kokufaneleka kanye nokuhlolwa ezimweni eziphindaphinda eduze kakhulu izimo ezihlukahlukene zomjikelezo wempilo lezi zinhlelo ezizosebenza ngaphansi kwazo kufanele zibuyekezwe futhi zisetshenziswe.Ukuthuthukiswa kwendlela yokuhlola kufanele kuthuthukiswe ukuze kube nokuhlolwa okungokoqobo nokumele.
Ngaphezu kwalokho,ukusebenzisana phakathi kwamakhemikhali nezinto zokusebenza kubalulekile ukuze uphumelele.Ukwakhiwa kwamavalvu ekhemikhali yomjovo kufanele kucabangele izakhiwo zamakhemikhali kanye nendawo yevalvu yomjovo emthonjeni.Kufanele kubhekwe njengokuhlanganisa amavalvu omjovo wangempela njengengxenye yempahla yokuhlola kanye nokwenza ukuhlolwa kokusebenza kwesikali esivimbelayo kanye nomklamo wamavalvu njengengxenye yohlelo lokufaneleka.Ukuze ufaneleke ama-scale inhibitors,okugxilwe kakhulu phambilini bekuyizinselelo zenqubo kanye nokuvimbela isikali,kodwa ukuvimbela okuhle kwesikali kuncike ekujovweni okuzinzile nokuqhubekayo.Ngaphandle komjovo ozinzile futhi oqhubekayo amandla esikali azokwanda.Uma i-valve ye-scale inhibitor injection i-gunk ed futhi ungekho umjovo we-scale inhibitor emfudlaneni woketshezi.,amavalvu omthombo kanye nokuphepha awavikelekile esikalini futhi ukukhiqizwa okuphephile kungase kube sengozini.Inqubo yokufaneleka kufanele inakekele izinselele ezihlobene nokujovwa kwe-scale inhibitor ngaphezu kwezinselele zenqubo kanye nokusebenza kahle kwesikali esifanelekayo.
Indlela entsha ihlanganisa imikhakha eminingi kanye nokubambisana phakathi kwemikhakha kanye nezibopho ezifanele kufanele kucaciswe.Kulolu hlelo lokusebenza uhlelo lwenqubo ye-topside,izifanekiso ze-subsea kanye nokuklanywa nokuqedwa kwemithombo kuhilelekile.Amanethiwekhi okuziphatha okuningi agxile ekuthuthukiseni izixazululo eziqinile zezinhlelo zokujova ngamakhemikhali abalulekile futhi mhlawumbe indlela yempumelelo.Ukuxhumana phakathi kwemikhakha eyahlukene kubalulekile;ikakhulukazi ukuxhumana phakathi kosokhemisi abalawula amakhemikhali asetshenziswayo kanye nonjiniyela bemithombo abalawula izinto ezisetshenziswa emthonjeni kubalulekile.Ukuqonda izinselelo zemikhakha eyahlukene nokufunda komunye nomunye kubalulekile ukuqonda ubunkimbinkimbi bayo yonke inqubo.
Isiphetho
● Umjovo oqhubekayo we-scale inhibitor ukuvikela i-DHS Vor ishubhu yokukhiqiza iyindlela enhle yokuvikela umthombo ngezikali.
● Ukuxazulula izinselele ezihlonziwe,izincomo ezilandelayo ziyi:
● Inqubo yokufaneleka ye-DHCI kufanele yenziwe.
● Indlela yokufaneleka yamavalvu omjovo wamakhemikhali
● Izindlela zokuhlola kanye nokufaneleka kokusebenza kwamakhemikhali
● Ukuthuthukiswa kwendlela
● Ukuhlolwa kwezinto ezifanele
● Ukusebenzisana kwezinhlaka eziningi lapho ukuxhumana phakathi kwemikhakha eyahlukene ehilelekile kubalulekile ukuze kube nempumelelo.
Ukubonga
Umbhali ufisa ukubonga i-Statoil AS A ngemvume yokushicilela lo msebenzi kanye no-Baker Hughes no-Schlumberger ngokuvumela ukusetshenziswa kwesithombe ku-Fig.2.
I-Nomenclature
(Ba/Sr)SO4=barium/strontium sulphate
I-CaCO3=i-calcium carbonate
I-DHCI=umjovo wekhemikhali we-downhole
I-DHSV=ivalvu yokuphepha ye-downhole
isib=isibonelo
GOR=isilinganiso sephethiloli
HSE=indawo yokuphepha kwezempilo
HPHT=izinga lokushisa eliphakeme lomfutho ophakeme
ID=ububanzi bangaphakathi
okungukuthi=lokho
km=amakhilomitha
mm=imilimitha
I-MEG=mono ethylene glycol
mMD=ukujula kukalwe imitha
OD=ububanzi bangaphandle
SI=i-scale inhibitor
mTV D=imitha ukujula okuqondile okuphelele
I-U-tube=Ishubhu elimise u-U
I-VPD=i-vapor pressure depressant
Umfanekiso 1. Uhlolojikelele lwezinhlelo zokujova amakhemikhali angaphansi kolwandle kanye ne-downhole emkhakheni we-atypical.Umdwebo wokujova ngamakhemikhali phezulu komfudlana we-DHSV kanye nezinselelo ezilindelekile ezihlobene.I-DHS V=ivalvu yokuphepha ye-downhole, i-PWV=inqubo ye-valve ephiko kanye ne-PM V=i-valve eyinhloko yenqubo.
Umfanekiso 2. Umdwebo wesistimu yomjovo wamakhemikhali we-atypical downhole nge-mandrel ne-valve.Isistimu ixhunywe endaweni eninginingi, yondliwe-futhi ixhunywe ku-tubing hanger ohlangothini lwe-annular lweshubhu.I-mandrel umjovo wamakhemikhali ngokwesiko ibekwe ekujuleni komthombo ngenhloso yokunikeza ukuvikelwa kwamakhemikhali.
Umfanekiso 3. Uhlelo olujwayelekile lokuvimba umthombo,lapho umbala ohlaza okwesibhakabhaka umele imvilophu evimbela umthombo oyinhloko;kulokhu ishubhu lokukhiqiza.Umbala obomvu umele imvilophu yesibili yokuvimbela;isikhwama.Ngakwesobunxele kukhonjiswa umjovo wamakhemikhali, umugqa omnyama onephuzu lomjovo oya eshubhuni lokukhiqiza endaweni ephawulwe ngokubomvu(umgoqo wesibili).
Umfanekiso 4. Imbobo eboshiwe itholwe engxenyeni engenhla yomugqa womjovo ongu-3/8”.Indawo iboniswa emdwebeni wohlelo lwesithiyo somthombo we-atypical, esimakwe ngombala osawolintshi.
Umfanekiso 5. Ukuhlasela kokugqwala okukhulu kushubhu we-Chrome ongu-7” 3%.Isibalo sibonisa ukuhlasela kokugqwala ngemva kwe-scale inhibitor efuthwe kusukela emugqeni womjovo wamakhemikhali ogobile ukuya eshubhuni yokukhiqiza.
Umfanekiso 6. Udoti otholakala kuvalvu yomjovo wamakhemikhali.Imfucumfucu kuleli cala kwakuyi-shavings yensimbi cishe kusukela ekufakweni kwayo ngaphezu kwemfucumfucu emhlophe.Ukuhlolwa kwemfucumfucu emhlophe kwafakazela ukuthi ama-polymer anamakhemikhali afana nekhemikhali ejovwe
Isikhathi sokuthumela: Apr-27-2022