Hdi thdo khoa hoc "Ndng cao he sd thu hdi ddu md Bqch Ho" cAc GiAi PHAP NANG CAO THU H6I DAU TRI^N VONG CHO THAN DAU M 6 N G M 6 BACH H 6 Pham Anh Tuan, Tran Le Dong, Le Dinh Lang XNLD Vietsovpetro AB[.]
Hdi thdo khoa hoc "Ndng cao he sd thu hdi ddu md Bqch Ho" cAc GiAi PHAP NANG CAO THU H6I DAU TRI^N VONG CHO THAN DAU M N G M BACH H Pham Anh Tuan, Tran Le Dong, Le Dinh Lang XNLD Vietsovpetro ABSTRACT Prospects of enhancing water flood efficiency for fractured basement resen/oir are analyzed in context of specific resen/oir charactehstics as well as the mechanism and technico-economical criteria of EOR method Based on analysis of the characteristics of oil recovery process in the fractured granite as well geological features, the ultimate recovery factor by water flood for the basement is estimated as high as 0.39, however this can only be achieved if the water flood was optimized Laboratory studies carried out on core samples have shown that the particular characteristics of the fractured basement rock have great impacts on oil displacement efficiency and the displacement efficiency of waterflood is the highest However there is a possibility of improving this displacement factor by injecting a slug of ion and non-ion surfactants, which are stable at high temperature and proven to significantly reduce the oil-water interfaclal tension The study show that the hydrodynamic methods such as optimization of the waterflood, which is being implemented on the field, water shut-off and injection profile modification should be the major EOR techniques for the fractured basement resen/oir These techniques are aimed at improving sweep efficiency of the water flood and blocking the water breakthrough channels in the resen/oir The results of laboratory & pilot test of non-organic gel injection for profile modification have shown that the so-called "self selective shut-off" mechanism, which has been working more or less successfully for the layering structure of the clastic resen/oir is not applicable for the case of highly heterogeneous fractured reservoir and at high temperature The guaranteed success of the water shut-off operation for a basement producing well should only be based on injecting the thermostable gel-forming system with using of appropriate packers GICJI THieu V A N D ^ Nang cao he sd thu hdi dau (THD) la mdt van de ludn dugc dat qua trinh khai thac cac md dau va ddi vdi mdt md Idn nhu Bach Ho thi van de lai cang cd y nghla dac biet quan trpng Kinh nghiem thuc tien tren the gidi viec nghien cUu Ung dung nhieu cdng nghe tang THD da cho thay hieu qua cua chung thudc rat Idn vao cac dieu kien dja chat - cdng nghe cu the cua md Than dau mdng nUt ne la mdt ddi tugng khai thac chu yeu d md Bach Hd, cho han 95% san lugng, nhung cd cau true rat phUc tap, muc dp bat ddng nhat va nhiet dp via deu rat cao Trong dieu kien dd viec nghien ciru xac dinh cac phuang phap, cdng nghe phu hgp vdi cac dac diem dia chat - khai thac cua mdng nut ne la mdt nhung van de rat quan trpng nham dam bao hieu qua cua cdng tac nang cao thu hdi dau I DAC DI^M CAU TROC COA OA MONG VA OAC TRLTNG QUA TRlNH OAY DAU Theo sd lieu nghien cUu mau Idi thi da chUa mdng md Bach Hd cd the dugc xep vao loai da hai dp rdng dp tham vdi dac trung d su khae biet rd ret ve dp rong cung nhu dp tham giua cac nUt ne macro va phan vi nut ne Khdng gian rdng da bao gdm hai phan chinh la cac nut ne - hang hoc Idn (macro) va cac khdi vi nut ne (micro) nam ke can vdi chung (Hinh 1), dd cac khe nUt macro la yeu td chinh tao nen dd tham, dd cac khdi vi nut ne (micro) cd dp tham khdng dang ke nhung lai ddng vai trd chu yeu kha nang chua cua da 22 Hdi thdo khoa hoc "Ndng cao he sdthu hdi ddu md Bach Hd " r'^^foS?^ ^# /^V-'^^ Hang hoc ^_^ y^ y:^i^-^~~^it/[ ^f^^ * ^ L ^ y '}^^^^'^