盘河断块区孔隙结构与驱油效率

PORE STRUCTURE AND OIL DISPLACEMENT EFFICIENCY IN PANHE FAULT-BLOCK AREA

盘河断块区位于惠民凹陷中央隆起带西部 ,其沙河街组三段储层可分为 4种孔隙结构类型。特高渗特大孔粗喉孔隙结构类型的储层在高含水期驱油效率最高 ,模拟实验时可达 70 %～ 90 % ,但在实际岩样中 ,由于结构的非均质性 ,驱油效率有所降低 (4 0 %～ 75 % ) ;高渗大孔粗喉孔隙结构类型的储层驱油效率较高 ,一般为60 %～ 80 % ;中渗大孔中喉孔隙结构类型的储层驱油效率较低 ,一般为 40 %～ 60 % ;低渗中孔细喉孔隙结构类型的储层驱油效率最低 ,一般为 3 0 %～ 5 0 %。但是 ,储层的孔隙系统并非由以上 4种单一类型组成 ,而是几种类型的复合。

Panhe fault-block area is located in the western part of central uplift zone in Huimin sag.The pore structure of reservoir in the 3rd member of Shahejie formation can be divided into four types. The reservoir with super-high permeability, super-large pore and coarse throat pore structure has the highest oil displacement efficiency during the high water-cut stage; the simulation test can be as high as 70%～90%.However,the test run in actual rock sample, the oil displacement efficiency seem to be reduced (40%～75%) ,due to the non-homogeneous structure. The reservoir with high permeability, large pore and coarse throat pore structure has high oil displacement efficiency, which is usually 60%～80%. The reservoir with medium permeability, large pore and medium throat pore structure has relatively low oil displacement efficiency of about 40%～60%; and the reservoir with low-permeability, medium pore and fine throat has the lowest oil displacement efficiency, 30%～50%.However,the pore system in the reservoir does not consist of only one of the above-mentioned 4 pore structures, it is exactly the composition of several types of pore structures.