Umphumela Wokucindezela Kwembobo Kumapharamitha E-Geophysical
I-Pendahuluan
Ku-geology kanye ne-geophysics, ukucindezela kwe-pore kungenye yezinto ezibaluleke kakhulu ezilawula ukuziphatha kwamatshe angaphansi komhlaba. Ukucindezela kwe-pore kuchazwa njengokucindezela koketshezi (amanzi, uwoyela, igesi, noma ingxube yalokhu) okugcwalisa izikhala ze-pore zedwala. Amanani okucindezela kwe-pore angahluka ngokujula, i-lithology, izimo ze-tectonic, kanye nomlando wokubekwa kanye nokuqina. Ezimweni eziningi, ukucindezela kwe-pore akulandeli umkhuba ojwayelekile we-hydrostatic, kodwa kungaba phezulu (ukucindezela ngokweqile) noma kube phansi (ukucindezeleka okungaphansi). Lokhu kuhlukahluka akugcini nje ngokuthinta ukuphepha kanye nomklamo wokubhoboza kodwa futhi kuthinta nemingcele ye-geophysical njengejubane lamagagasi okuzamazama komhlaba, ubuningi, ukumelana, impendulo ye-acoustic log, kanye nezimfanelo ze-seismic ezisetshenziselwa ukuhumusha i-reservoir. Lesi sihloko sixoxa ngendlela ukucindezela kwe-pore okuthinta ngayo imingcele ye-geophysical, izindlela zayo, kanye nemiphumela yayo ekuhlolweni nasekuchazeni okungaphansi komhlaba.
Imiqondo Eyisisekelo: Ukucindezeleka Kwe-Pore, Ukucindezeleka Okuphumelelayo, kanye Nohlaka Lwedwala
Ubudlelwano obuyinhloko obuxhumanisa ingcindezi yembobo kanye nezakhiwo zomzimba zedwala buchazwa ngumqondo wokucindezeleka okusebenzayo. Ngamagama alula, ukucindezeleka okusebenzayo ukucindezeleka empeleni "okuthwalwa" uhlaka lwedwala, hhayi uketshezi lwembobo. Ekwakhiweni kukaTerzaghi okuvamile, ukucindezeleka okusebenzayo (σ') kungabhalwa kanje:
σ' = σ – Pp ,
lapho u-σ kuyingcindezi iyonke (ukucindezeleka okungaphezu komthwalo) kanti u-Pp kuyingcindezi yembobo. Njengoba ingcindezi yembobo ikhula, ukucindezeleka okusebenzayo kwehla. Lokhu kwehla kokucindezeleka okusebenzayo kwenza uhlaka lwedwala "lube mnene" futhi luguquguquke kalula. Lolu shintsho ekuqineni luthinta ngqo ijubane lamagagasi okuzamazama komhlaba (i-Vp ne-Vs), i-elastic modulus, kanye nezinye izimpendulo ze-geophysical ezihlobene ne-porosity kanye nokucindezelwa kwe-medium.
Umphumela Wokucindezela Kwe-Pore Esivinini Samagagasi E-Seismic
1. Ijubane le-P Wave (Vp)
Amagagasi e-P azwela kakhulu ezinguqukweni ze-bulk modulus kanye nobuningi bamadwala. Njengoba ukucindezela kwama-pore kukhuphuka, ukucindezeleka okusebenzayo kuyancipha, kwenza kube buthaka ukuxhumana phakathi kwama-granular futhi kwenze idwala licindezeleke kakhulu. Ngenxa yalokho, i-Vp ivame ukwehla. Lo mphumela ubonakala kakhulu emadwaleni e-shale kanye ne-sandstone sedimentary, lapho ama-pore esadlala indima esebenzayo ekusebenzeni kwamadwala.
Ngaphansi kwezimo zokucindezela ngokweqile, ukwehla kwe-Vp kuvame ukusetshenziswa njengesibonakaliso esingaqondile. Ezindaweni eziningi zokudonsa amanzi, izindawo zokucindezela ngokweqile zibonisa ijubane eliphansi ngendlela engavamile uma kuqhathaniswa nomkhuba ojwayelekile wokuminyana. Ngakho-ke, ukuhlaziywa kwejubane kanye nezingodo zezwi kuyizinto ezibalulekile zokubikezela ukucindezela kwe-pore ngaphambi kokubhoboza.
2. Ijubane le-S Wave (Vs)
Igagasi le-S lihlobene kakhulu ne-shear modulus, enqunywa kakhulu uhlaka lwedwala, hhayi uketshezi. Kodwa-ke, izinguquko ekucindezelekeni okusebenzayo zisathinta ukuqina kohlaka, ngakho-ke ama-V angancipha njengoba ukucindezela kwama-pore kukhuphuka. Nakuba i-Vs ngokuvamile ingazweli kakhulu ekushintsheni koketshezi kune-Vp, emadwaleni abuthakathaka kakhulu noma anezimbobo eziningi, umphumela wokunciphisa ukucindezeleka okusebenzayo ungaba mkhulu. Isilinganiso se-Vp/Vs sivame ukusetshenziselwa ukuhlola izinguquko ezinwebekayo ezingase zihlobane nokucindezela kwama-pore kanye nokugcwala koketshezi.
3. Izimfanelo Zokuzamazama Komhlaba kanye Nokuphakama Kwawo
Ukucindezela kwe-Pore kuthinta impedance ye-acoustic (AI = ρVp). Uma i-Vp yehla futhi ubuningi bungakhuphuki kakhulu, impedance ye-acoustic izokwehla. Lokhu kungafani kwe-impedance kuthinta ubukhulu bokubonakaliswa kokuzamazama komhlaba. Kwezinye izimo, ukucindezela ngokweqile kungakhiqiza izibonisi ezinamandla noma amaphethini athile okuzamazama komhlaba, yize ukuhumusha kufanele kuqaphe njengoba imiphumela ye-lithological kanye noketshezi lwe-hydrocarbon nakho kungaveza izimpendulo ezifanayo.
Umphumela ku-Density kanye ne-Porosity Esebenzayo
Ubuningi bamadwala ekujuleni ngokuvamile buyanda ngenxa yokuqina, kuyilapho ukuqina kwemigodi kwehla. Kodwa-ke, lapho ukucindezela kwemigodi kuphezulu, ukuqina kuyavinjelwa: imigodi ihlala inkulu kunalokho okufanele ibe khona kulokho kujula. Ngenxa yalokho, ukuqina kwemigodi kungaba phezulu kanti ubuningi bungaba ngaphansi kunezindlela ezijwayelekile. Lesi simo sivame ukutholakala ku-shale ecindezelwe kakhulu ngenxa yokuqina okungaphelele (ukuqina okungaphelele). Kusukela kulogi yokuqina, izindawo zokucindezela ngokweqile zingatholakala njengobunzima obuphansi kunokulindelekile ekujuleni okunikeziwe.
Umphumela ekuqineni nasekuqhubeni amandla
Ukumelana namadwala kuthonywa kakhulu uhlobo loketshezi lwembobo, usawoti, ukuxhumana kwembobo, kanye nokuqukethwe kobumba. Ukucindezela kwembobo akushintshi ngokuqondile ukumelana nokushintsha njengokushintsha kokugcwala kwe-hydrocarbon, kodwa kungathinta ukumelana ngezindlela ezingaqondile:
1. Izinguquko ku-porosity kanye ne-pore microstructure: Ukucindezela ngokweqile okugcina i-porosity ephezulu kungandisa umthamo wamanzi aqhubayo futhi kunciphise ukumelana.
2. Izinguquko ekugcwaleni noma ekufudukeni koketshezi: Kwezinye izinhlelo zikaphethiloli, ukucindezeleka okuphezulu kwe-pore kuhlotshaniswa nokuqongelela kwegesi noma i-hydrocarbon, okungandisa ukumelana. Kodwa-ke, lokhu akubangelwa ukucindezeleka kwe-pore kuphela, kodwa kunalokho kungenxa yokuguquguquka koketshezi.
3. Imiphumela yamakhemikhali okushisa kanye noketshezi: Izindawo ezicindezela kakhulu ngezinye izikhathi zihlotshaniswa namazinga okushisa aphezulu kanye nezinguquko kusawoti, okushintsha nokumelana.
Ngenxa yezici eziningi ezihambisanayo, ukumelana akuvamile ukusetshenziswa njengesibonakaliso esiyinhloko sokucindezela kwe-pore ngaphandle kokusekelwa olunye ulwazi (idatha ye-sonic, ubuningi, kanye nokubhoboza).
Ithonya ku-Acoustic Log (Sonic Log) kanye nokubikezela ukucindezeleka kwe-Pore
Amalogi e-Sonic alinganisa isikhathi sokuhamba kwamagagasi e-acoustic (Δt). Njengoba i-Vp incipha, i-Δt iyanda. Ekuchazeni ingcindezi ye-pore, indlela evamile ukuqhathanisa i-Δt elinganisiwe nethrendi evamile yokucindezela. I-Δt enkulu kunethrendi evamile ekujuleni okunikeziwe ivame ukuhunyushwa njengokubonisa ukucindezela ngokweqile, ikakhulukazi ku-shale. Izindlela zokuhlola ezifana nendlela ka-Eaton zisebenzisa ukuphambuka kwelogi ye-sonic (noma yokumelana) kusuka kuthrendi evamile ukuze kulinganiswe i-gradient yengcindezi ye-pore. Nakuba le ndlela iwusizo, ukusetshenziswa kwayo kudinga ukulinganiswa ngedatha yokuhlola ukwakheka, izinsimbi zodaka, noma ingcindezi eqondile ukuze kugwenywe ukubandlulula ngenxa yezinguquko ku-lithology.
I-Elastic Modulus kanye nobudlelwano bayo nokucindezeleka kwe-Pore
Amapharamitha e-Geomechanical njenge-Young's modulus (E), i-bulk modulus (K), kanye ne-Poisson's ratio (ν) nawo ayashintsha ngokushintsha kokucindezela kwe-pore ngoba ancike ekucindezelekeni okusebenzayo kanye nezimo zokuxhumana kwezinhlamvu. Ngokuvamile, ukwanda kokucindezela kwe-pore kunciphisa ukuqina kwedwala (ukwehla kwe-E kanye ne-K). Lokhu kubalulekile kumongo walokhu:
– Ukuqina kwemigodi: ukucindezela ngokweqile kunciphisa ukucindezeleka okusebenzayo ukuze idwala liwe noma liguquguquke kalula.
– Ubunjiniyela bedamu: Ukukhiqizwa koketshezi kunciphisa ukucindezeleka kwe-pore, kwandisa ukucindezeleka okusebenzayo, futhi kungabangela ukuqina kwedamu kanye nokuwa komhlaba. Lezi zinguquko ziqashwa nge-4D seismic (isikhathi esidlulayo).
Imiphumela Yokuchazwa Kwesimo Sezwe kanye Nokuchazwa Kwesimo Sezwe
Ukushintsha kwezingcindezi ze-pore kungadala ukungalingani kokuzamazama komhlaba okuthi ngezinye izikhathi kuhunyushwe kabi njengezinguquko ku-lithology noma kuma-hydrocarbon. Isibonelo, indawo enejubane eliphansi ingase iphazanyiswe nengqimba enezimbobo eziningi noma egcwele igesi, kodwa futhi kungenzeka ukuthi ibangelwa ukucindezela ngokweqile. Ngakho-ke, incazelo ehlanganisiwe ifanelekile:
1. Ukulinganisa ngedatha yomthombo (isisindo sodaka, i-RFT/MDT, i-DST, ilogi yobuningi be-sonic).
2. Ukuhlaziywa kwezitayela zokuminyana kwe-shale njengereferensi.
3. Ukumodela i-Rock physics (isb. ukushintshaniswa koketshezi lwe-Gassmann okuhambisana nokulungiswa kokucindezeleka okusebenzayo) ukuze kuhlukaniswe imiphumela yoketshezi kanye nengcindezi.
4. Ukuhlanganiswa kwe-geomechanics ukuze izinguquko ezinwebekayo ziqondwe ohlakeni lokucindezeleka.
Isiphetho
Umfutho we-Pore unethonya elinamandla kumapharamitha e-geophysical ngoba ulawula ukucindezeleka okusebenzayo okunquma ukuqina kohlaka lwedwala. Ukwanda komfutho we-pore ngokuvamile kunciphisa i-Vp ne-Vs, kwandisa isikhathi sokuhamba kwe-sonic log, kugcina i-porosity ephezulu, futhi kunciphisa ubuningi obukhulu uma kuqhathaniswa nemikhuba evamile yokuqina. Ukumelana nakho kungathinteka ngokungaqondile ngokushintsha kwe-porosity, usawoti, noma i-fluid dynamics. Ekusetshenzisweni okusebenzayo, ukuqonda ubudlelwano phakathi komfutho we-pore kanye nempendulo ye-geophysical kubalulekile ekubikezelweni kwengcindezi yangaphambi kokubhoboza, ukuchazwa kwe-seismic okunembile kakhudlwana, kanye nokuphathwa kwengozi ye-geomechanical kanye nokukhiqiza. Indlela ehlanganisiwe—ukuhlanganisa amamodeli e-seismic, izingodo zemithombo, kanye ne-rock physics—kuyisihluthulelo sokuhlukanisa imiphumela yengcindezi ye-pore kusuka ku-lithology kanye nemiphumela ye-fluid, okuholela ekuchazeni okuthembekile kakhulu kwe-subsurface.
