NUMERIČKO MODELIRANJE UTJECAJA POČETNE DISTRIBUCIJE ZASIĆENJA VODOM NA IZVEDBU ZAVODNJAVANJA TOPLOM VODOM U NEIZOTERMNIM UVJETIMA

The heterogeneity in the spatial distribution of initial water saturation influences the performance of hot water flooding. The prospect of a reduction in oil recovery arises from the development of viscous instability. In the present study, a numerical simulation model has been developed by coupling heat transport, and multiphase flow in porous media integrated with the non-isothermal flow, and the numerical model has been verified with the existing analytical solution by Buckley and Leverett. The formation of a wavy temperature profile at the condensation front was found with a decreased depth of temperature penetration. The average rise of temperature is drastically affected by the spatial distribution of initial water saturation. The formation of viscous fingering was highly dominating in the reservoir, with initial water saturation randomly distributed and causing the front to move in an irregular pattern from the initial stage of the flooding. The heterogeneous reservoir with initial water distribution showed the earlier formation of viscous fingering than the homogeneous reservoir. The heterogeneity in the spatial distribution of initial water saturation had caused viscous instability, lower viscosity reduction, lower displacement sweeps efficiency, and higher residual oil saturation. The present study is limited to spatial distribution in initial water saturation to a certain degree of heterogeneity. The heterogeneity in the spatial distribution of initial water saturation highly impacted the production performance of hot water flooding. The present study provides an idea for the implementation and future development of hot water flooding in a randomly initial water saturation distributed environment.Heterogenost u prostornoj distribuciji početog zasićenja vodom utječe na izvedbu zavodnjavanja toplom vodom. Smanjenje iscrpka nafte proizlazi iz povećanja nestabilnosti viskoznosti. U ovom je istraživanju razvijen numerički simulacijski model, koji uključuje prijenos topline i višefazni protok u poroznoj sredini integriran s neizotermnim protokom, pri čemu je navedeni numerički model potvrđen postojećim analitičkim rješenjem Buckleya i Leveretta. Sa smanjenem dubine prodiranja topline utvrđeno je stvaranje valovitog temperaturnog profila na fronti kondenzacije. Na prosječni porast temperature drastično utječe prostorna raspodjela početnog zasićenja vodom. U ležištu s nasumično raspoređenim početnim zasićenjem vodom domininantno je bilo prstoliko prodiranje vode (engl. fingering) koje je od početne faze zavodnjavanje uzrokovalo pomicanje fronte u nepravilnom obrascu. Heterogeno ležište s početnom raspodjelom vode pokazalo je raniju pojavu prstolikog prodiranja utisnute tople vode od homogenog ležišta. Heterogenost u prostornoj distribuciji početnog zasićenja vodom uzrokovala je nestabilnost viskoznosti, manje smanjenje viskoznosti, niži koeficijent istiskivanja fluida i veću zasićenost zaostalom naftom. Ovo istraživanje je ograničeno na prostornu distribuciju početnog zasićenja vodom do određenog stupnja heterogenosti. Heterogenost u prostornoj distribuciji početnog zasićenja vodom uvelike je utjecala na proizvodni učinak zavodnjavanja toplom vodom. Ovo istraživanje daje ideju za implementaciju i budući razvoj zavodnjavanja toplom vodom u poroznoj sredini s nasumično raspodijeljenim početnim zasićenjem vodom