秦皇岛32-6油田南区明下段Ⅰ油组3小层河道砂体叠置类型及其动态响应特征

Study on stacking patterns of multi-staged channel sand and its function on production performance in sub-layer lower N mⅠ~3,southarea of QHD32-6 oilfield

秦皇岛32-6油田南区明下段Ⅰ油组3小层(Nm下Ⅰ3小层)为多期叠置而成的河道砂体,精细解剖砂体的叠置特征是进一步挖潜的重点。基于高分辨率层序地层学原理,对该小层多期河道沉积期次进行了划分与对比,在此基础上,对同一期次砂体沉积微相特征、不同期次砂体之间的夹层特征进行了研究。结果表明,该小层河道砂体可划分为切叠河道型、叠置河道型、单一河道型3种主要叠置类型。由实验井组示踪剂追踪结果可知,不同期次砂体之间的水驱前缘推进速度低于同一期次砂体的推进速度,而同期次砂体之间的水驱前缘推进速度也存在差异。示踪剂跟踪实验证实,对于多期河道叠置砂体而言,叠置类型、单一砂体微相特征及夹层分布共同影响了开发效果。当注采层位分布于不同期次砂体时,其连通关系首先取决于砂体的叠置类型及夹层分布;而当注采层位分布于相同期次砂体时,其连通关系主要取决于沉积微相的变化。

The sub-layer lower NmⅠ3in the south area of QHD32-6 oilfield is a multi-staged channel sand, therefore, how to corre-late it into single stage is important for its development potential. Using the high resolution sequence stratigraphy, the different-stagedchannel sand can be identified and correlated. There are main 3 stacking patterns, which are superimposition type, cutting type and sin-gle channel type. Furthermore, the characteristics of micro-facies within the single-stage sand and interbed distribution can be stud-ied. The tracer in experimental well group shows that, the driving rate of waterflooding front from one stage sand body to another is low-er than the value in the same-staged sand body where there is also a discrepancy because of the change of microfacies. This paper con-cludes that, for the multi-staged channel sand, the stacking patterns, changing microfacies and interbeds distribution are the main fac-tors effecting production performance. Meanwhile, which one is the most important among those factors depends on the relationship be-tween the twosand bodieswithin which the injector and producerlayers are located.