川东石炭系有效储层下限标准的确定

DEFINITION OF LOWER LIMIT OF CARBONIFEROUS NET PAY RESERVOIRS IN EAST SICHUAN

周文 王允诚 张高信 冉宏 蒲家奇

Zhou Wen Wang Yuncheng Zhang Gaoxing Ran Hong Pu Jiaqi

将川东石炭系储层划分为中孔中渗(Ⅰ级)、中孔低渗(Ⅱ级)、低孔低渗(Ⅲ级)和超低孔渗(Ⅳ级)4级,提出以2%及50%的孔隙度、含水饱和度界线划分储层和非储层,再依据储层级别及其所处气水界面以上位置,通过对比注入浮力与各级别毛细管阻力大小,来判断储层是否为有效储层的方法──浮力-毛细管阻力比较法。通过比较认为,Ⅰ级、Ⅱ级、Ⅲ级、Ⅲ级储层只要分别位于气水界面以上5m,25m,60m和100m,即为有效储层。

Carboniferous dolomite reservoirs in East Sichuan could be divided into four grade: 1.middle porsity-middle permeability(grade-I); 2. middle porosity-lower permeability (gradeⅡ); 3. lower porosity-lower permeability (grade-Ⅲ); 4. ultra low porosity-ultra low permeability (grade-Ⅳ).Reservoirs and nonreservoirs could be distinguished by 20% of porosityand 50% of water saturation. Based on the reservoir grades and their position above watergas boundary, the contrast of injected buoyance and different capillary pressures, a newmethod-bouyance-capillary pressure contrast method is proposed in this paper so as to determine a reservoir to be net pay one or not. The result suggests that the reservoirs ofgraded I above water-gas boundary 5 m,of grade-Ⅱ above the boundary 25 m, of grade-Ⅲ above the boundary 60 m and of grade-Ⅲ above the boundary 100 m are all net pay reservolrs.

10.11743/ogg19960415