Qhov viscosity ntawm cov kua qaub tawg txiav txim siab qhov hydraulic fracturing breakdown pressure uas xav tau rau qhov pib tawg thiab tswj kev tawg hauv pob zeb. Kev ntsuas thiab kev tswj hwm qhov tseeb ntawm cov kua viscosity yog qhov tseem ceeb rau kev ua kom zoo dua qhov geometry ntawm qhov tawg, txhawb kev txhim kho qhov tawg nkhaus, thiab xyuas kom meej tias cov kua qaub sib npaug raws cov ntsej muag tawg. Kev xaiv qhov viscosity tsim nyog tiv thaiv cov kua dej ntau dhau mus rau hauv qhov tsim thiab txhim kho cov kua qaub etching rau kev txhim kho qhov tawg, thaum kawg cuam tshuam rau qib ntawm kev loj hlob ntawm cov pob zeb tawg los ntawm cov kua qaub thiab ua kom muaj txiaj ntsig zoo dua ntawm thaj chaw tso dej roj.
Lub Hom Phiaj Tseem Ceeb ntawm Acid Fracturing Fluid
Kev kho mob kua qaub tawg yogessential inkev txhawb nqa lub pas dejofCov pob zeb shale uas muaj qhov porosity tsawg thiab permeability tsawg. Lub hom phiaj tseem ceeb yog kov yeej cov teeb meem ntuj tsim thiab txhim kho kev rov qab los ntawm hydrocarbon los ntawm kev tsim cov txoj hauv kev conductive hauv cov pob zeb nruj. Acid fracturing ua tiav qhov no los ntawm ob txoj hauv kev: tsim cov pob zeb tawg los ntawm kev txhaj tshuaj acid, thiab tom qab ntawd nthuav dav thiab etching cov pob zeb tawg no los ntawm kev tswj cov tshuaj tiv thaiv acid-pob zeb. Qhov no nthuav dav thaj chaw tso dej roj thiab txhim kho kev tsim khoom ntawm cov cheeb tsam uas yav dhau los cuam tshuam los ntawm kev puas tsuaj ntawm cov pob zeb lossis tsis txaus permeability.
Ib qho kev sib tw ntxiv yog kev kho cov kua qaub tawg kom phim cov lithology thiab cov txheej txheem ntawm lub pas dej. Cov txheej txheem ua rau cov kua qaub-pob zeb thiab cov kua qaub-pob zeb sib txawv ntau nrog cov mineralogy, siab, kub, thiab kev siv cov kua hydraulic fracturing. Qhov no tsis yog tsuas yog cuam tshuam rau qhov nrawm thiab hom ntawm etching tab sis kuj tseem muaj kev pheej hmoo ntawm kev thaiv kev tsim, av nplaum o, lossis kev sib cuam tshuam geochemical tsis zoo, txhua yam uas tuaj yeem ua rau muaj kev sib txhuam thiab txwv tsis pub muaj kev tsim khoom mus sij hawm ntev.
Lub Chaw Khaws Roj Shale
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Cov Ntsiab Lus ntawm Acid Fracturing hauv Shale Oil Reservoirs
Cov txheej txheem ntawm kev tsim pob txha tawg
Kev tsim cov pob zeb tawg hauv cov chaw khaws roj shale nruj yog nyob ntawm kev kov yeej qhov kev ntxhov siab siab thiab lub zog pob zeb los ntawm hydraulic lossis acid fracturing. Hauv cov chaw permeability qis no, txoj hauv kev loj rau kev ntws roj tsis tshua muaj. Lub hauv paus ntsiab lus cuam tshuam nrog kev txhaj tshuaj kua qaub fracturing ntawm qhov siab txaus kom dhau qhov hydraulic fracturing breakdown pressure - qhov tsawg kawg nkaus uas xav tau los pib tawg hauv pob zeb matrix. Cov txheej txheem no nyob ntawm cov txheej txheem pob zeb tseem ceeb: thaum lub siab siv dhau qhov kev tawg, cov pob zeb tawg tshiab tsim, feem ntau ua raws li txoj kev tsis kam qis tshaj plaws uas tau teev los ntawm cov dav hlau bedding, cov pob zeb tawg ntuj, thiab cov txheej txheem anisotropy hauv pob zeb.
Lub zog siab ntawm kev tawg pob zeb txawv raws li hom pob zeb thiab cov kua tawg. Cov kev tshawb fawb qhia tau tias cov kua xws li CO₂ tsim cov zog siab dua ntawm kev tawg pob zeb thiab cov tes hauj lwm tawg pob zeb nyuaj dua piv rau H₂O lossis N₂. Cov txheej txheem kuj nyob ntawm lub zog tensile ntawm kev tsim, modulus ntawm elasticity, thiab qhov muaj cov dav hlau tsis muaj zog. Kev tshawb fawb txog qhov deb tseem ceeb - qhia los ntawm kev sim hauv chaw kuaj mob thiab hauv thaj chaw - ua qauv rau lub zog pib tawg pob zeb uas tsim nyog ua haujlwm ntawm qhov muaj zog ntawm qhov tawg pob zeb, kwv yees qhov twg thiab thaum twg qhov kev nthuav dav tsis ruaj khov yuav tshwm sim.
Qhov nyuaj hauv lub network tawg uas tsim tau ntxiv los ntawm kev tsom mus rau kev loj hlob ntawm cov tawg raws cov kab nkhaus es tsis yog cov dav hlau ncaj. Txoj hauv kev no ua rau kom muaj qhov ntim ntawm lub pas dej. Cov txheej txheem xws li kev tawg ntawm lub zog cyclic pressure shock ua rau muaj kev cuam tshuam ntawm lub zog, ua rau rov pib dua thiab sib sau ua ke ntawm cov tawg uas ceg thiab nkhaus, ua tau zoo hauv kev taug kev ntawm cov teeb meem lithological thiab lamination heterogeneity. Cov tawg uas nyuaj, ntau ceg uas tsim los ntawm txoj kev no ua rau thaj chaw ntws dej ntau tshaj plaws thiab txhim kho kev nkag mus rau cov hydrocarbons uas tau cais tawm yav dhau los.
Kev tsim cov pob zeb tawg kuj nyob ntawm kev koom ua ke ntawm cov xwm txheej geological thiab kev tswj hwm kev ua haujlwm. Cov yam ntxwv geological—xws li kev ntxhov siab, kev faib ua pawg, mineralogy, thiab qhov muaj cov seams tsis muaj zog—tswj cov kev uas cov pob zeb tawg tuaj yeem taug kev. Kev hloov kho engineering, suav nrog cov kua qaub tawg thiab kev tswj hwm lub zog dynamic, ua rau muaj kev tsim cov tes hauj lwm uas phim cov khoom ntuj ntawm lub pas dej.
Cov yam ntxwv ntawm lub pas dej uas cuam tshuam rau kev tawg ntawm cov kua qaub
Qhov tsis muaj permeability thiab porosity qis yog cov yam ntxwv ntawm cov roj shale reservoirs. Ob qho tib si txwv tsis pub cov kua dej ntws los ntawm ntuj, ua rau kev tawg zoo tseem ceeb rau kev tsim khoom. Hauv cov kab ke matrix ultratight, qhov tawg uas ua rau muaj yuav tsum dav txaus kom txuas nrog cov tes hauj lwm pore lossis microfractures uas twb muaj lawm. Txawm li cas los xij, qhov loj ntawm qhov tawg los ntawm cov kua qaub feem ntau tsis sib xws vim muaj kev sib txawv hauv cov pob zeb, mineralogy, thiab cov qauv.
Qhov porosity thiab permeability tswj cov kua dej xau thiab kev thauj mus los ntawm cov kua qaub. Hauv cov pob zeb uas muaj cov qauv pore tsis zoo lossis cov microfractures sib txuas ua ke tsawg, cov kua qaub xau raug txwv, ua rau cov kua qaub etching hauv hydraulic fracturing tsis zoo. Qhov twg cov channel seepage ntuj tsis muaj lossis tortuous heev, cov txheej txheem los txhim kho kev sib txuas ntawm cov channel ua qhov tseem ceeb. Cov kev daws teeb meem channel seepage ntuj tsis zoo yuav suav nrog cov voj voog fracturing rov ua dua, siv cov diverters, lossis cov kab ke kho mob sib xyaw.
Qhov sib txawv ntawm pob zeb—txheej sib txawv, qhov sib txawv ntawm qhov tawg, thiab kev faib tawm ntawm cov ntxhia—tsim cov kev xaiv zoo rau ob qho kev tawg thiab kev xau tawm. Cov txheej txheem ua rau cov kua qaub-pob zeb thiab qhov nrawm ntawm cov kua qaub-pob zeb sib txawv thoob plaws hauv lub pas dej, tshwj xeeb tshaj yog nyob ze ntawm cov pob zeb sib txawv. Qhov twg cov kua qaub ntsib cov kab carbonate uas muaj ntau, cov tshuaj tiv thaiv sai tuaj yeem tsim qhov dav ntawm qhov tawg tsis sib xws thiab cov qauv tawg ceg. Qhov no tuaj yeem txhawb lossis cuam tshuam kev sib txuas nyob ntawm qhov sib txawv ntawm qhov chaw.
Cov kua dej xau tawm yog lwm qhov teeb meem hauv cov pob zeb shales uas tawg ua ntau hom. Kev xau tawm ntau hauv cov cheeb tsam uas muaj porosity ntau lossis qhib qhov tawg tuaj yeem txwv tsis pub cov pob zeb tawg loj hlob. Ntawm qhov tod tes, cov cheeb tsam xau tawm tsawg tuaj yeem cuam tshuam kev nkag mus ntawm cov kua qaub thiab tom qab ntawd nthuav dav ntawm cov pob zeb tawg. Kev tsim cov kua qaub tawg - suav nrog kev siv cov kua qaub gelled lossis crosslinked, thiab cov kua ntxiv uas tsim rau hom pob zeb - cuam tshuam ncaj qha rau cov txiaj ntsig no, ua rau cov neeg ua haujlwm txhim kho cov pob zeb porosity qis thiab ua kom zoo dua thaj chaw tso dej roj.
Kev txhawb nqa zoo hauv cov chaw nyuaj no xav tau ob qho kev tsom mus rau: kev tswj hwm qhov tseeb ntawm cov txheej txheem tawg thiab kev txhim kho cov khoom thauj pob zeb los ntawm kev tsim cov kua dej tawg thiab kev ua haujlwm. Kev siv acid etching rau kev txhim kho qhov tawg, tswj kev xau tawm, thiab kev tawg raws txoj kev nkhaus yog qhov tseem ceeb rau kev kov yeej cov teeb meem uas tshwm sim los ntawm kev nkag mus tsawg thiab kev sib txuas tsis zoo hauv cov chaw khaws roj shale.
Cov kua qaub ua kua qaub: Cov khoom sib xyaw, viscosity, thiab kev ua tau zoo
Cov Cheebtsam thiab Kev Tsim Cov Kua Acid Fracturing
Cov kua qaub uas tawg ua kua yog tsim los ntawm kev kho cov tshuaj lom neeg kom ua rau cov khoom tawg zoo tshaj plaws thiab rov qab tau roj. Cov kua qaub uas siv ntau tshaj plaws yog hydrochloric acid (HCl), feem ntau yog nyob rau hauv cov concentration ntawm 5% txog 28%, xaiv raws li lub reservoir lithology thiab kev kho mob lub hom phiaj. Lwm cov kua qaub suav nrog cov organic acids xws li acetic lossis formic acid rau cov kua mos dua lossiscov qauv uas rhiab rau qhov kub thiab txiasCov kev sib xyaw ua ke lossis cov txheej txheem kua qaub uas tau teeb tsa tuaj yeem siv los siv cov tshuaj sib txawv raws lub sijhawm kho mob.
Cov tshuaj ntxiv tseem ceeb nrog cov kua qaub. Cov tshuaj tiv thaiv kev xeb, cov tshuaj ua kom muaj zog, cov tshuaj tswj hlau, thiab cov tshuaj tsis yog emulsifiers tiv thaiv cov raj, txo cov dej nag, thiab tiv thaiv kev tsim cov emulsion. Cov polymers hluavtaws tau sib xyaw ua ke ua cov khoom ua kom tuab - feem ntau yog cov polyacrylamide hydrolyzed (HPAM) lossis cov copolymers tshiab - kom nce viscosity rau qhov chaw zoo dua rau cov kua qaub, proppant suspension, thiab tswj kev xau. Surfactants, ob qho tib si anionic (piv txwv li, sodium dodecyl sulfate) thiab non-ionic (piv txwv li, ethoxylated alcohols), yog qhov tseem ceeb rau kev ruaj khov ntawm cov kab ke ua npuas ncauj, txhim kho kev hloov pauv ntawm kev ntub dej, thiab txo qhov nro ntawm qhov chaw kom zoo dua qub rau kev sib cuag ntawm pob zeb thiab kua qaub.
Kev xau thiab kev tswj cov khoom seem yog qhov tseem ceeb heev. Cov tshuaj ntxiv uas ua rau cov kua dej poob xws li cov hmoov txhuv nplej siab lossis cov polymers tsim tshiab txo qhov nkag mus rau hauv lub matrix, ua kom cov kua qaub nyob hauv qhov tawg. Cov khoom tawg—oxidative (piv txwv li, persulfate) lossis enzymatic—tau siv los rhuav tshem cov khoom tuab tom qab kev kho mob, txo qhov kev pheej hmoo ntawm cov khoom seem thiab kev puas tsuaj tom qab. Txawm li cas los xij, kev sib cuam tshuam nrog cov dej tsim tawm lossis cov khoom tawg qis dua qhov kub yuav ua rau muaj cov pob zeb hauv av thib ob xws li barite, xav tau kev kuaj xyuas qhov sib xws ntawm lub kaw lus.
Piv txwv ntawm cov qauv tsim kho tshiab suav nrog:
- Cov txheej txheem kua qaub qeeb: siv cov surfactant-polymer gels los qeeb cov tshuaj tiv thaiv kua qaub-polymer rau kev nkag mus tob dua hauv cov txheej carbonate nruj.
- Cov polymers uas kub thiab txias, tiv taus ntsev (piv txwv li, P3A synthetic copolymers) rau qhov viscosity ruaj khov thiab tsawg kawg nkaus cov khoom seem hauv cov qhov dej tob.
- Tshuaj ntsuab, suav nrog L-ascorbic acid, ua rau muaj kev khaws cia viscosity thiab kev tiv thaiv antioxidant ntawm txog li 300 ° F yam tsis muaj cov khoom lag luam ib puag ncig.
Kev Ntsuas Viscosity thiab Qhov Tseem Ceeb hauv Acid Fracturing
Kev ntsuas qhov tseeb ntawm cov kua qaub ncaug tawg yuav tsum tau ua kom raugcov ntsuas viscometer siab, kub siab (HPHT)muaj peev xwm ua qauv qhia txog kev ntxhov siab thiab qhov kub thiab txias hauv qhov av. Cov txheej txheem tseem ceeb suav nrog:
- Cov viscometers tig rau kev txiav txim siab viscosity puag.
- HPHT viscometers rau cov txheej txheem siab heev, ntsuas tus cwj pwm viscoelastic nyob rau hauv cyclic thermal lossis pressure loads.
Qhov tseem ceeb ntawm viscosity yog ntau yam:
- Cov Qauv Etching thiab Kev Loj Hlob ntawm Pob Txha: Cov kua qaub uas muaj viscosity qis dua ua rau muaj cov kab mob wormholes lossis pitting etch patterns ntau dua; viscosity siab dua txhawb kom muaj kev loj hlob ntawm cov channel dav dua, sib xws dua, uas tswj hwm qhov kev ua kom tawg thiab qhov loj hlob. Piv txwv li, kev nce cov thickener concentration ua rau thaj chaw etched dav dua thiab kev loj hlob ntawm qhov tawg nyuaj, raws li kev sim hauv thaj teb thiab cov xim zas xim lees paub.
- Kev Nkag Tau thiab Kev Faib Tawm ntawm Pob TxhaCov kua dej khov zoo dua tswj tau qhov chaw ntawm cov kua qaub, txhawb kom cov kua qaub nkag mus rau hauv cov pob zeb tawg ntuj thib ob thiab ua kom thaj chaw tso roj ntau tshaj plaws. Kev ntsuam xyuas ntau yam siv kev ntsuas conductivity tom qab txiav txuas cov viscosities siab dua rau cov tes hauj lwm tawg uas faib tawm thiab ruaj khov dua, sib raug zoo nrog cov nqi tsim khoom siab dua.
Piv txwv li, hauv Marcellus shale uas muaj carbonate ntau, siv cov txheej txheem acid uas tsim los ntawm tus kheej lossis cov txheej txheem cross-linked acid—qhov twg dynamic viscosity tseem tswj tau txawm tias nyob rau hauv qhov kub ntawm lub pas dej—ua rau muaj tsawg kawg 20-30% qhov nyuaj ntawm kev tawg thiab kev npog dej ntau dua piv rau HCl uas tsis tau hloov kho.
Kev Sib Tham Txog Acid-Rock hauv Acid Fracturing
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Kev Tshawb Fawb Txog Acid-Rock thiab Lawv Txoj Kev Sib Raug Zoo rau Viscosity
Cov txheej txheem ua tshuaj lom neeg ntawm cov kua qaub thiab pob zeb raug cuam tshuam los ntawm cov kua dej viscosity. Cov txheej txheem kua qaub ib txwm ua tshuaj lom neeg sai sai nrog cov zaub mov carbonate, tsom mus rau kev yaj ze ntawm lub qhov dej thiab txwv qhov tob nkag mus. Cov txheej txheem kua qaub qeeb qeeb, siv cov surfactants viscoelastic lossis polymer-acid emulsions, txo qhov nrawm ntawm cov hydrogen ions diffusion, qeeb qhov nrawm ntawm cov kua qaub thiab pob zeb ua tshuaj lom neeg tag nrho. Qhov no ua rau cov kua qaub nkag mus tob dua rau hauv cov qauv qis-permeability lossis qis-porosity ua ntej siv, txhawb kev etching dav dua thiab kev tawg ntev dua.
Kev hloov kho ntawm qhov nrawm ntawm cov tshuaj tiv thaiv tuaj yeem hloov kho los ntawm:
- Kho qhov sib piv ntawm surfactant/polymer kom zoo rau kev sib kis ntawm cov kua qaub.
- Kev ua kom cov kua qaub ntau zuj zus—hloov cov tshuaj txhaj kua qaub qeeb thiab tsis tu ncua—ua tiav qhov sib npaug ntawm qhov ze ntawm lub qhov dej thiab qhov tob ntawm cov kua qaub, raws li pom hauv kev sim txhaj tshuaj sib law liag qhov twg cov txheej txheem kua qaub hloov pauv ua rau muaj cov kua qaub ntau zuj zus thiab txhim kho kev txhawb nqa ntawm lub pas dej.
Cov teebmeem synergistic tshwm sim los ntawm kev sib xyaw ua ke:
- Cov polymers ua ke nrog cov nonionic surfactants tsim kom muaj zog thiab ua rau muaj kev tiv thaiv thermal thiab ntsev, raws li tau lees paub los ntawm kev ntsuam xyuas cov khoom rheological thiab xuab zeb nqa nyob rau hauv cov xwm txheej simulated reservoir.
- Cov sib xyaw ua ke ntawm Alkali-surfactant-polymer (ASP), thiab cov tshuab nanocomposite (piv txwv li, graphene oxide-polymer), txhim kho ob qho tib si qhov kev tswj tus nqi thiab kev ruaj khov ntawm cov kua qaub, thaum tseem pab tswj cov ntaub ntawv thiab tshem tawm cov kua qaub seem - qhov tseem ceeb rau kev ua kom zoo dua cov kua qaub tawg hauv cov channel seepage heterogeneous thiab rau kev txhim kho kev rov qab los ntawm cov qauv qis-permeability lossis qis-porosity.
Cov qauv iav me me thiab kev sim dej nyab hauv av lees paub tias cov qauv tsim tshwj xeeb no ua rau lub sijhawm sib cuag nrog cov kua qaub ntau ntxiv, qeeb qeeb ua rau cov tshuaj tiv thaiv nrog cov zaub mov, txhim kho thaj chaw etched, thiab thaum kawg nthuav cov dej ntws ntawm cov roj, qhia txog kev sib raug zoo ntawm cov kua qaub tawg, viscosity, acid-rock reaction kinetics, thiab tag nrho cov kev ua haujlwm ntawm cov dej khib nyiab.
Kev Cuam Tshuam ntawm Fracture Geometry rau Acid Penetration thiab Kev Ua Haujlwm Zoo
Qhov geometry ntawm qhov tawg—tshwj xeeb yog qhov ntev, dav (qhov qhib), thiab qhov faib tawm ntawm qhov chaw—txiav txim siab qhov nkag mus rau hauv cov kua qaub thiab yog li ntawd qhov ua tau zoo ntawm kev tawg kua qaub. Qhov tawg ntev thiab dav txhawb kev faib tawm ntawm cov kua qaub ntau heev, tab sis qhov ua tau zoo tuaj yeem txo qis vim yog qhov "kev tawg," qhov twg cov kua qaub tsis tau siv sai sai mus txog qhov kawg ntawm qhov tawg yam tsis tau teb tag nrho raws txoj kev. Qhov sib txawv ntawm qhov qhib, tshwj xeeb tshaj yog cov pob tawg uas muaj channel lossis phab ntsa ntxhib uas tsim los ntawm kev khawb tsis sib xws, txhawb kev nkag mus ntau dua los ntawm kev muab txoj hauv kev zoo dua thiab txo qhov poob kua qaub ua ntej.
- Kev hloov pauv ntawm qhov aperture:Cov chaw channelized tsim los ntawm acid etching tswj cov conductivity nyob rau hauv kev ntxhov siab thiab muab cov kev thauj mus los acid nyiam.
- Kev tso chaw:Cov pob txha tawg ze ntawm lub qhov dej ua rau muaj kev faib cov kua qaub sib npaug ntau dua, thaum cov pob txha tawg deb lossis cov ceg ntoo siab tau txais txiaj ntsig los ntawm kev txhaj tshuaj kua qaub lossis kev hloov pauv kua qaub/tsis muaj zog.
- Kev txhaj tshuaj ntau theem:Cov kua qaub hloov pauv thiab cov kua dej sib cais tuaj yeem ua rau cov pob txha tawg rov qab zoo li qub, ua rau nkag mus tob dua thiab ua kom cov pob txha tawg ntuj thiab pob txha tawg loj dua.
Kev tshawb nrhiav hauv thaj chaw thiab chaw kuaj mob siv micro-CT scanning thiab numerical modeling qhia tau hais tias geometric complexity thiab roughness tswj tau ob qho tib si acid-rock reaction rates thiab qhov kawg ntawm permeability enhancing. Yog li ntawd, kev tsim acid fracturing kom zoo phim cov khoom acid system thiab cov txheej txheem txhaj tshuaj rau cov qauv tawg tshwj xeeb ntawm lub pas dej, ua kom ntseeg tau tias qhov siab tshaj plaws, ruaj khov fracture conductivity thiab txhim kho kev rov qab roj.
Cov Tswv Yim Txhim Kho Kom Zoo Rau Kev Ua Kom Acid Fracturing Zoo
Kev Xaiv Cov Txheej Txheem Acid thiab Cov Khoom Ntxiv
Kev ua kom cov kua qaub tawg zoo dua yog nyob ntawm kev xaiv cov txheej txheem kua qaub kom raug. Cov txheej txheem kua qaub qeeb qeeb, xws li cov kua qaub gelled lossis emulsified, yog tsim los ua kom qeeb qeeb ntawm cov tshuaj tiv thaiv kua qaub-pob zeb. Qhov no ua rau nkag mus tob dua raws qhov tawg thiab ua kom cov kua qaub sib npaug zoo dua. Qhov sib piv, cov txheej txheem kua qaub ib txwm muaj - feem ntau yog cov kua qaub hydrochloric tsis hloov pauv - teb sai, feem ntau txwv qhov tob ntawm cov kua qaub nkag mus thiab txwv qhov ntev ntawm qhov tawg, tshwj xeeb tshaj yog hauv cov chaw khaws dej carbonate thiab cov chaw khaws dej kub siab. Cov kev txhim kho tsis ntev los no suav nrog cov txheej txheem kua qaub khov, tsim rau cov chaw khaws dej kub siab heev, uas ua rau qeeb qeeb ntawm cov tshuaj tiv thaiv, txo cov xeb thiab ua kom muaj txiaj ntsig zoo dua los ntawm kev ua haujlwm kua qaub ntev thiab txhim kho cov pob zeb yaj.
Thaum piv cov tshuab uas tsis txawj ntse piv rau cov tshuab ib txwm muaj:
- Cov kua qaub uas qeeb qeebnyiam dua nyob rau hauv cov chaw uas cov kua qaub ntau dhau sai sai ze ntawm lub qhov dej ua rau txo qis qhov ncav cuag thiab kev sib xws ntawm kev kho mob. Cov kua qaub no tau pom tias ua rau cov pob txha tawg loj dua los ntawm cov kua qaub thiab txhim kho kev coj ua tom qab pob txha tawg thiab thaj chaw ntws roj.
- Cov kua qaub ib txwm muajtej zaum yuav txaus rau kev kho mob tsis tob lossis thaj chaw uas nkag tau yooj yim uas qhov kev teb sai thiab kev nkag mus tsawg kawg nkaus yog qhov lees txais.
Kev xaiv cov viscosity modifiers—xws li viscoelastic surfactants (VCA systems) lossis polymer-based gelling agents—nyob ntawm cov yam ntxwv tshwj xeeb ntawm lub reservoir:
- Qhov kub ntawm lub pas dej thiab cov mineralogy qhia txog kev ruaj khov ntawm cov tshuaj lom neeg thiab kev ua tau zoo ntawm cov viscosity modifiers.
- Rau cov ntawv thov kub siab, cov khoom tawg gel ruaj khov xws li cov neeg sawv cev encapsulated oxidizing lossis acid-etching capsules yog qhov tsim nyog los xyuas kom meej tias cov kua qaub gelled tawg thiab kev ntxuav tom qab kho kom zoo.
- Qhov viscosity profile yuav tsum tau kho kom haum rau cov kua qaub ncaug fracturing kom tswj tau qhov viscosity.txaus viscositythaum lub sijhawm twj tso kua mis (txhim kho qhov dav ntawm qhov tawg thiab kev ncua proppant) tseem tuaj yeem raug rhuav tshem tag nrho los ntawm cov gel breakers rau kev ntws rov qab zoo.
Kev xaiv cov khoom ntxiv kom raug yuav txo qhov kev puas tsuaj ntawm cov qauv, ua kom muaj kev cuam tshuam zoo rau cov kua qaub rau kev txhim kho qhov tawg, thiab ua kom zoo tshaj plaws hauv cov pas dej uas tsis muaj permeability thiab qis porosity. Cov ntawv thov hauv thaj chaw tsis ntev los no qhia tau hais tias cov kua qaub tawg raws li VCA, nrog rau cov gel breakers sib phim zoo, ua rau muaj kev ntxuav zoo dua, txo cov kua dej poob, thiab txhim kho kev txhawb nqa pas dej piv rau cov txheej txheem ib txwm muaj.
Cov Txheej Txheem Ua Haujlwm Uas Cuam Tshuam Rau Kev Ua Kom Acid Stimulation Zoo
Kev tswj hwm kev ua haujlwm thaum lub sijhawm kua qaub tawg ua rau muaj kev cuam tshuam loj heev rau cov txiaj ntsig. Cov txheej txheem ua haujlwm tseem ceeb suav nrog qhov nrawm ntawm lub twj tso kua qaub, qhov ntim kua qaub uas txhaj, thiab kev tswj hwm qhov siab:
- Tus nqi twj tso kua mis: Txheeb xyuas qhov ceev ntawm qhov tawg thiab geometry. Qhov nrawm dua ua rau cov kua qaub nkag mus tob dua thiab ua rau cov kua qaub thiab pob zeb sib cuam tshuam tas mus li, tab sis yuav tsum sib npaug kom tsis txhob muaj cov kua qaub ntau dhau lossis kev loj hlob ntawm qhov tawg uas tsis tuaj yeem tswj tau.
- Qhov ntim ntawm cov kua qaub txhaj tshuaj: Cuam tshuam rau qhov ntev thiab dav ntawm cov pob txha tawg uas raug kua qaub. Feem ntau xav tau cov ntim loj dua rau cov qauv uas tsis muaj permeability, txawm hais tias kev ua kom cov kua qaub zoo dua nrog rau cov viscosity modifiers tuaj yeem txo qhov kev siv tshuaj tsis tsim nyog thaum tseem khaws cov conductivity.
- Kev tswj siabKev tswj lub qhov hauv qab thiab qhov siab ntawm qhov chaw ua kom qhov tawg tseem qhib, pab txhawb kev poob dej, thiab coj cov kua qaub mus rau thaj chaw tawg.
Hauv kev xyaum ua, cov sijhawm txhaj tshuaj kua qaub uas tau teem sijhawm lossis hloov pauv—qhov twg cov hom kua qaub lossis cov viscosities tau hloov pauv—tau pom tias ua rau muaj kev txhim kho txoj kev tsim cov kav dej, txhawb kev tawg ntawm cov pob txha nkhaus, thiab ua kom thaj chaw tso roj av zoo dua. Piv txwv li, kev txhaj tshuaj kua qaub uas hloov pauv ob theem tuaj yeem tsim cov kav dej tob dua, muaj cov kav dej zoo dua, ua tau zoo dua li cov txheej txheem ib theem hauv ob qho chaw kuaj mob thiab thaj chaw ua haujlwm.
Kev sib phim cov txheej txheem acidizing rau qhov sib txawv ntawm cov pas dej yog qhov tseem ceeb heev. Hauv cov pas dej shale uas muaj cov mineralogy sib txawv thiab cov pob zeb tawg ntuj, kev kwv yees ua qauv thiab kev saib xyuas lub sijhawm tiag tiag yog siv los coj lub sijhawm thiab kev txhaj tshuaj. Kev hloov kho raws li cov yam ntxwv tawg (piv txwv li, kev taw qhia, kev sib txuas, kev txhim kho cov dej ntws ntuj) tso cai rau cov neeg teb xov tooj kom kho cov kev ua haujlwm kom zoo rau kev txhawb siab tshaj plaws thiab kev puas tsuaj tsawg kawg nkaus.
Kev Ua Qauv Kwv Yees thiab Kev Sib Koom Ua Ke ntawm Cov Ntaub Ntawv
Kev tsim cov kua qaub tawg niaj hnub no suav nrog cov qauv kwv yees uas sib piv cov kev ua haujlwm, cov khoom ntawm cov kua qaub tawg, thiab kev coj ua tom qab tawg. Cov qauv siab heev suav nrog:
- Cov txheej txheem thiab qhov nrawm ntawm cov tshuaj tiv thaiv acid-pob zeb, ntes tau seb cov qauv acid thiab etching hloov pauv li cas hauv qab cov xwm txheej hauv daim teb.
- Cov yam ntxwv tshwj xeeb ntawm lub pas dejxws li porosity thiab permeability, mineralogical heterogeneity, thiab preexisting fracture networks.
Cov qauv no siv cov ntaub ntawv empirical, cov txiaj ntsig kuaj hauv chaw kuaj, thiab kev kawm tshuab los kwv yees seb kev hloov pauv ntawm viscosity, tus nqi twj tso kua mis, acid concentration, thiab thermal profiles cuam tshuam li cas rau cov txheej txheem tsim pob txha hauv hydraulic fracturing thiab kev ua kom zoo dua thaj chaw tso dej ntws mus sij hawm ntev.
Cov lus qhia tseem ceeb hauv kev sib phim cov kev txwv ntawm thaj chaw thiab kev tsim qauv ua haujlwm suav nrog:
- Xaiv cov viscosity thiab cov kua qaub raws li qhov xav tau ntawm cov kua qaub-pob zeb, qhov kub thiab txias xav tau, thiab cov hom phiaj ua tiav (piv txwv li, ua kom cov pob zeb porosity tsawg permeability lossis daws cov teeb meem tsis zoo ntawm cov dej ntws ntuj).
- Siv cov txheej txheem uas tsav los ntawm cov ntaub ntawv los kho cov sijhawm txhaj tshuaj kua qaub, qhov nrawm ntawm lub twj tso kua qaub, thiab cov koob tshuaj ntawm cov tshuaj breaker, ua kom zoo dua qhov loj ntawm qhov tawg thiab kev rov zoo tom qab kho.
Piv txwv los ntawm kev xa tawm hauv thaj chaw tsis ntev los no qhia tau tias cov txheej txheem kwv yees no ua rau muaj kev coj ua tom qab tawg thiab txhim kho kev kwv yees roj, ua rau muaj kev siv cov tswv yim tawg kua qaub zoo dua thiab txhim khu kev qha thoob plaws cov chaw khaws cia shale thiab carbonate.
Nthuav Qhov Chaw Nqus Roj Thiab Txhawb Kev Ua Haujlwm Ntawm Qhov tawg
Kev Tshem Tawm Kev Thaiv thiab Kev Txhim Kho Kev Sib Txuas Lus
Kev siv cov kua qaub los ua kom tawg yog ib txoj hauv kev tseem ceeb hauv kev siv cov kua qaub los ua kom tawg kom kov yeej qhov kev sib tw ntawm kev thaiv kev tsim, xws li kev sib sau ua ke ntawm cov dej noo thiab kev ua kom cov zaub mov tawg, hauv cov chaw khaws cia shale. Thaum cov kua qaub—feem ntau yog hydrochloric acid (HCl)—raug txhaj, nws ua rau cov zaub mov uas muaj zog xws li calcite thiab dolomite. Txoj kev ua kom tawg ntawm cov kua qaub thiab pob zeb no yaj cov khoom muaj zog, ua rau cov qhov me me loj dua, thiab txuas cov qhov me me uas tau cais tawm yav dhau los, ncaj qha txhim kho qhov porosity thiab permeability hauv cov chaw khaws cia roj. Qhov nrawm ntawm cov kua qaub thiab pob zeb, nrog rau cov kua qaub tshwj xeeb uas siv, sib txawv nyob ntawm cov mineralogy shale thiab cov khoom sib xyaw ua ke.
Hauv cov shales uas muaj carbonate ntau, cov concentration siab dua ntawm HCl ua rau muaj kev tshem tawm thiab kev thaiv ntau dua vim yog cov tshuaj tiv thaiv acid-rock sai dua thiab ua haujlwm tau zoo dua. Kev kho cov kua qaub rau cov ntsiab lus tshwj xeeb ntawm carbonate thiab silicate ntawm lub pas dej ua rau cov txheej txheem tshem tawm zoo dua, rov qab kho cov channel seepage ntuj thiab daws cov teeb meem channel seepage tsis zoo. Qhov roughness ntawm cov ntsej muag tawg uas twb muaj lawm nce ntxiv vim yog cov kua qaub yaj, ncaj qha cuam tshuam nrog kev ua kom tawg zoo dua thiab cov channel ntws ruaj khov dua rau cov hydrocarbons. Lub tshuab no tau raug lees paub los ntawm cov ntaub ntawv sim uas qhia txog kev txhim kho tseem ceeb hauv kev tsim roj thiab cov ntsuas kev txhaj tshuaj tom qab kev kho cov kua qaub hauv cov qauv qis-permeability.
Kev ua kom tawg tas mus li yog qhov tseem ceeb rau kev tsim khoom mus sij hawm ntev ntawm cov qhov dej roj shale. Raws sij hawm, kev tawg uas ua rau muaj peev xwm poob kev ua kom muaj peev xwm vim yog kev sib tsoo proppant, diagenesis, embedment, lossis kev tsiv teb tsaws chaw zoo. Cov txheej txheem no txo cov kev qhib uas tsim los ntawm hydraulic fracturing breakdown pressure, cuam tshuam loj heev rau kev rov qab los ntawm hydrocarbons. Kev ua qauv lej thiab kev tshawb fawb hauv chaw kuaj mob qhia tias yog tsis muaj kev tswj hwm zoo, kev puas tsuaj proppant tuaj yeem txo qhov kev tsim khoom txog li 80% dhau 10 xyoo. Cov yam xws li kev kaw lub siab, qhov loj me ntawm proppant, thiab cov khoom ntawm qhov tawg qub ua lub luag haujlwm tseem ceeb. Kev xaiv cov proppant tsim nyog thiab kev tswj hwm cov kev ntxhov siab hauv qhov downhole yog qhov tseem ceeb los tswj cov kev loj hlob uas tsim los ntawm acid etching rau kev ntws roj thiab roj.
Kev Loj Hlob thiab Kev Txij Nkawm ntawm Fracture Network
Kev nthuav dav thaj chaw tso roj av kom dav dua yog nyob ntawm kev tsim thiab kev siv cov txheej txheem tswj cov kua qaub. Cov no yog cov txheej txheem kua qaub tawg uas muaj cov khoom ntxiv - xws li cov tshuaj tiv thaiv, cov neeg sawv cev gelling, thiab cov tshuaj surfactants - los tswj cov kua qaub, tswj cov kua qaub-pob zeb teb, thiab txo cov kua dej xau thaum kho. Qhov tshwm sim yog cov txheej txheem etching uas tsom mus rau ntau dua uas ua rau cov txheej txheem tsim cov pob txha tawg hauv hydraulic fracturing thiab txhawb nqa kev nthuav dav ntawm ob qho tib si thawj zaug thiab thib ob (curved) pob txha tawg.
Cov txheej txheem tswj cov kua qaub, tshwj xeeb tshaj yog cov kua qaub gelled thiab cov kua qaub gel hauv qhov chaw, pab tswj qhov chaw thiab lub neej ntev ntawm cov kua qaub hauv cov pob zeb tawg. Cov txheej txheem no qeeb qeeb qhov kev sib cuam tshuam ntawm cov kua qaub-pob zeb, nthuav qhov deb ntawm kev nkag mus thiab tso cai rau kev txiav cov kua qaub kom ntau dua rau kev txhim kho kev tawg. Txoj hauv kev no ua rau cov pob zeb raug txhawb nqa ntau dua, nthuav dav thaj chaw tso dej ntawm cov roj, thiab daws cov teeb meem nrog cov kev daws teeb meem tsis zoo hauv cov dej ntws hauv ob qho chaw carbonate thiab shale. Cov ntaub ntawv hauv thaj chaw qhia tau hais tias cov txheej txheem no tsim cov tes hauj lwm tawg dav dua, txuas ntxiv dua, tsav tsheb rov qab tau cov hydrocarbon ntau dua.
Kev tswj kom muaj kev txhim kho permeability nyob rau hauv dynamic reservoir stress yog lwm qhov tseem ceeb uas yuav tsum xav txog. Cov pob zeb uas raug kev nyuaj siab kaw ntau zaus ua rau qhov dav ntawm cov pob zeb txo qis lossis kaw ua ntej lub sijhawm, ua rau muaj kev cuam tshuam rau conductivity. Yuav kom tiv thaiv qhov no, muaj ntau txoj hauv kev siv:
- Kev siv tshuab perforation uas muaj kev ntxhov siab:Txoj kev no ua rau muaj kev tswj hwm kev pib thiab kev nthuav dav ntawm cov pob txha tawg, ua kom zoo dua qhov kev sib haum xeeb ntawm kev siv zog txhawb nqa thiab kev nthuav dav ntawm cov pob txha tawg. Piv txwv li, hauv Jiyang Depression, cov thev naus laus zis no txo cov zog xav tau los ntawm 37% thaum txhim kho ob qho kev sib txuas thiab cov txiaj ntsig ib puag ncig.
- Kev kho mob ua ntej acidizing:Siv cov polyhydrogen acid systems lossis lwm cov kua dej ua ntej-acid fracturing tuaj yeem txo qhov kev nyuaj siab ntawm kev tawg pob txha thiab txo qhov kev thaiv kev tsim thawj zaug, teeb tsa theem rau kev tsim pob txha zoo dua thiab ruaj khov dua.
- Kev tsim qauv geomechanical:Kev sib koom ua kekev ntsuas kev ntxhov siab tiag tiagthiab kev saib xyuas lub pas dej tso cai rau kev kwv yees thiab kev hloov kho ntawm cov kev kho mob kua qaub, pab txhawb kev ua kom tawg txawm tias muaj kev hloov pauv ntawm cov xwm txheej kev ntxhov siab hauv qhov chaw.
Cov txheej txheem no—ua ke nrog cov khoom siv hydraulic fracturing fluid additives thiab acid fracturing fluid formulation—ua kom ntseeg tau tias cov permeability zoo dua qub. Lawv pab cov neeg ua haujlwm roj loj hlob thiab tswj cov tes hauj lwm tawg, txhim kho cov pob zeb porosity qis thiab txhawb nqa kev rho tawm cov peev txheej mus sij hawm ntev.
Hauv kev xaus, los ntawm kev sib xyaw ua ke ntawm cov kev coj ua tshiab ntawm acid etching, cov txheej txheem tswj hwm acid siab heev, thiab cov tswv yim geomechanically-informed fracturing, cov txheej txheem niaj hnub no txhawb nqa cov pas dej tam sim no tsom mus rau ob qho tib si ua kom cov chaw ntws hydrocarbon tam sim ntawd thiab khaws cia qhov kev coj ua ntawm qhov tawg uas xav tau rau kev ua haujlwm ntau lawm.
Xaus lus
Kev ntsuas thiab kev ua kom zoo dua ntawm cov kua qaub tawg uas muaj viscosity yog qhov tseem ceeb rau kev ua kom muaj kev tawg ntau tshaj plaws, kev ua haujlwm ntawm cov kua qaub, thiab kev ntws roj mus ntev hauv cov shale formations. Cov kev coj ua zoo tshaj plaws yog qhia los ntawm kev nkag siab zoo txog cov kua dej hauv qab cov xwm txheej ntawm cov chaw khaws roj, nrog rau kev koom ua ke ntawm cov ntaub ntawv hauv chaw kuaj mob thiab thaj chaw kom ntseeg tau tias muaj txiaj ntsig zoo rau kev ua haujlwm.
Cov Lus Nug Feem Ntau
Q1: Qhov tseem ceeb ntawm cov kua qaub ncaug tawg hauv cov roj shale yog dab tsi?
Qhov viscosity ntawm cov kua qaub uas tawg yog qhov tseem ceeb rau kev tswj kev tawg thiab kev nthuav dav hauv cov chaw khaws roj shale. Cov kua uas muaj viscosity siab, xws li cov kua qaub uas sib txuas lossis gelled, tsim cov pob tawg dav dua thiab ntau ceg. Qhov no ua rau muaj qhov chaw zoo dua ntawm cov kua qaub thiab pob zeb thiab ua kom ntev kev sib cuag ntawm cov kua qaub thiab pob zeb, ua kom cov tshuaj tiv thaiv acid-pob zeb zoo dua thiab ua kom cov kua qaub sib xyaw ua ke tob thiab sib npaug. Qhov viscosity ntawm cov kua qaub zoo tshaj plaws ua rau qhov dav thiab qhov nyuaj ntawm cov pob tawg ntau dua, cuam tshuam ncaj qha rau kev ua haujlwm ntawm cov kua qaub etching rau kev txhim kho pob tawg thiab kev ua kom zoo dua ntawm thaj chaw tso dej ntawm cov roj. Piv txwv li, cov kua CO₂ uas tuab dua tau pom tias txhim kho qhov dav ntawm cov pob tawg thiab tswj tau qhov permeability tom qab kho, thaum cov kua uas muaj viscosity qis ua rau cov pob tawg ntev dua, nqaim dua nrog kev nthuav dav yooj yim dua tab sis yuav muaj kev pheej hmoo tsis txaus etching lossis channeling ntawm cov kua qaub ntws. Kev xaiv qhov viscosity zoo hauv cov kua qaub tawg ua kom ntseeg tau tias muaj kev tawg ntawm kev thaiv kev tsim, kev ua haujlwm tawg mus sij hawm ntev, thiab kev nthuav dav ntawm thaj chaw tso dej tsim khoom.
Q2: Lub zog tawg hauv hydraulic fracturing cuam tshuam li cas rau kev tsim pob txha tawg?
Lub zog tawg yog lub zog tsawg kawg nkaus uas xav tau los pib tawg hauv pob zeb thaum lub sijhawm hydraulic fracturing. Hauv cov chaw khaws roj shale uas muaj qhov tsis tshua muaj permeability, kev tswj hwm qhov tseeb ntawm lub zog tawg yog qhov tseem ceeb. Yog tias lub zog siv qis dhau, qhov tawg yuav tsis qhib, txwv tsis pub cov kua nkag. Siab dhau, thiab qhov tawg yuav tsis tuaj yeem tswj tau, muaj kev pheej hmoo ntawm kev tawg tsis zoo. Kev tswj hwm kom zoo txhawb kom cov tawg tsim raws li cov dav hlau ntuj thiab txawm tias txoj kev nkhaus, txhim kho kev txhawb nqa lub chaw khaws roj. Lub zog tawg siab dua, thaum tswj hwm kom zoo, tsim cov tes hauj lwm tawg nyuaj dua thiab txhim kho kev sib txuas tseem ceeb rau cov kua qaub kom ncav cuag thiab khawb thaj chaw dav dua. Cov txheej txheem xws li borehole notching siv los txo qhov siab tawg thiab tswj hwm qhov tawg zoo dua, cuam tshuam rau ob qho tib si geometry tawg thiab kev ua haujlwm kis. Qhov kev tswj hwm paub txog lub zog tawg hydraulic fracturing yog qhov tseem ceeb rau cov txheej txheem tsim tawg siab heev hauv cov chaw khaws roj tsis zoo.
Q3: Vim li cas acid etching thiab enlargement thiaj li pab tau rau cov pas dej uas tsis muaj permeability thiab porosity qis?
Cov dej ntws uas tsis muaj permeability thiab cov dej ntws uas tsis muaj porosity ua rau muaj cov channel seepage ntuj tsawg, uas txwv tsis pub cov roj txav mus los thiab tsim khoom. Acid etching hauv hydraulic fracturing siv cov kua dej reactive los yaj cov feem ntawm cov pob zeb matrix raws cov ntsej muag tawg, yog li ua rau cov kev ntws no loj dua. Qhov no txo qhov kev thaiv kev tsim thiab muab cov channel tshiab rau cov kua dej kom txav mus los tau yooj yim dua. Cov txheej txheem txhawb nqa cov dej ntws tsis ntev los no, suav nrog cov txheej txheem sib xyaw thiab cov txheej txheem ua ntej-acid, tau ua tiav kev coj ua tau zoo dua, kav ntev thiab txhim kho kev rov qab roj. Cov txheej txheem no muaj txiaj ntsig zoo rau kev txhim kho cov dej ntws uas tsis muaj permeability thiab txhim kho cov pob zeb uas tsis muaj porosity, raws li pom hauv kev tshawb fawb hauv thaj teb thiab hauv chaw kuaj mob. Qhov tshwm sim yog kev nce ntxiv ntawm kev tsim khoom zoo, nrog rau cov kua qaub-etched thiab cov pob zeb tawg loj ua haujlwm ua cov kav dej zoo dua rau cov dej ntws hydrocarbon.
Q4: Lub luag haujlwm ntawm porosity thiab permeability ntawm pob zeb ua lub luag haujlwm dab tsi hauv kev ua tiav ntawm acid fracturing?
Qhov porosity thiab permeability ncaj qha txiav txim siab qhov kev txav ntawm cov kua thiab kev nkag mus rau cov kua qaub hauv cov chaw khaws roj. Cov pob zeb uas muaj porosity qis thiab permeability qis cuam tshuam kev sib kis thiab kev ua haujlwm ntawm cov kua qaub tawg, txwv tsis pub ua tiav ntawm kev ua haujlwm txhawb nqa. Txhawm rau daws qhov no, cov kua qaub tawg yog tsim tshwj xeeb los suav nrog cov tshuaj tiv thaiv kev tswj hwm thiab cov viscosity modifiers. Kev txhim kho porosity los ntawm kev ua haujlwm ntawm cov kua qaub-pob zeb ua rau muaj qhov chaw khoob rau kev khaws cia hydrocarbon, thaum txhawb nqa permeability tso cai rau kev ntws yooj yim dua los ntawm cov tes hauj lwm tawg. Tom qab kev kho acid, ntau txoj kev tshawb fawb tau qhia txog kev nce ntxiv ntawm ob qho tib si porosity thiab permeability, tshwj xeeb tshaj yog qhov twg cov channel seepage ntuj tsis zoo yav dhau los. Kev txhim kho cov kev ntsuas no ua rau muaj kev sib kis ntawm cov kua qaub tawg zoo tshaj plaws, cov nqi tsim khoom ruaj khov, thiab thaj chaw sib cuag ntawm cov chaw khaws roj ntev dua.
Q5: Cov tshuaj tiv thaiv acid-rock cuam tshuam li cas rau qhov ua tau zoo ntawm kev nthuav dav thaj chaw ntws dej?
Lub tshuab ua haujlwm ntawm cov kua qaub-pob zeb tswj hwm seb pob zeb yaj li cas thiab cov pob txha tawg li cas thaum lub sijhawm tawg kua qaub. Kev tswj hwm qhov nrawm ntawm cov kua qaub-pob zeb yog qhov tseem ceeb heev: ceev dhau, thiab cov kua qaub siv ze ntawm lub qhov dej, txwv tsis pub nkag mus; qeeb dhau, thiab kev tawg tej zaum yuav tsis txaus. Los ntawm kev tswj hwm qhov kev ua haujlwm los ntawm cov kua viscosity, acid concentration, thiab cov khoom ntxiv, kev tawg raws cov ntsej muag tawg tau ua tiav, ua rau muaj kev sib txuas ntawm cov pob txha tawg dav dua thiab tob dua. Kev ua qauv siab heev thiab kev tshawb fawb hauv chaw kuaj mob lees paub tias kev ua kom zoo dua ntawm cov kua qaub-pob zeb ua rau muaj cov pob txha tawg zoo li channel, uas ua rau thaj chaw ntws roj nthuav dav heev. Piv txwv li, cov pob txha tawg uas tau tawg los ntawm channelized acid tau sau tseg tias muaj kev ua tau zoo txog tsib zaug ntau dua li cov pob txha tawg uas tsis tau tawg hauv cov qauv carbonate. Kev kho kom zoo ntawm cov kua qaub tawg thiab cov txheej txheem txhaj tshuaj yog li txiav txim siab qhov loj thiab kev ua haujlwm ntawm kev txhim kho thaj chaw ntws.
Lub sijhawm tshaj tawm: Kaum Ib Hlis-10-2025
