喇8-182井区聚合物驱不可及孔隙体积研究

STUDY ON INACCESSIBLE PORE VOLUME OF POLYMER FLOODING IN WELL LA 8-182

喇嘛甸油田喇8-182井区高Ⅱ1-18油层渗透率低、物性差,属于三类油层,是聚合物驱的主力接替潜力层。文中在油层性质对比分析的基础上,应用计算法和数值模拟方法研究了高Ⅱ1-18油层的聚合物驱不可及孔隙体积并进行了对比。研究结果表明,计算法简单易行,成本低,能够充分考虑分子量、矿化度等的影响;但这种方法只考虑了由于孔隙直径过小而导致的不可及孔隙体积,无法表达由于压力梯度不足而造成的不可及孔隙体积,因此计算结果偏小,只适合于分子量的初步优选。数值模拟方法充分考虑了启动压力梯度和压力场的影响,计算结果更加符合实际情况,适合于在已经初步选定分子量范围的情况下,模拟不可及孔隙体积。不可及孔隙体积随注入速度增加而减小,高Ⅱ1-18油层不可及孔隙体积在0.2～0.3之间。最后建议喇8-182井区聚合物驱注入速度控制在0.2PV/a以内。

The features of Gao Ⅱ1-18 oil layers in borefield La 8-182 of La-ma-dian oilfield are low permeability and poor physical property. It is main succeeding layers of polymer flooding. The inaccessible pore volume of polymer flooding in Gao Ⅱ1-18 oil layers is studied based on the comparative analysis of layer characters. The research results showed that the numerical simulation is feasible, the inaccessible pore volume will descend with the increase of injection rate, and the inaccessible pore volume is between 0.2 and 0.3 in Gao Ⅱ1-18 oil layers.