正断层发育区煤储层特征及压裂参数优化--以柿庄南区块为例

Characteristics and fracturing parameters optimization of coal reservoirs near normal fault:a case study of Shizhuang South Block

为高效开发正断层附近的煤层气资源,基于测试、测井、水力压裂等资料,利用“测距”法分析了正断层发育区煤储层的地应力、煤体结构和裂隙分布与距断层距离的关系。结合宏观与微观研究方法得出:正断层发育区煤储层发育特征具有明显的分带性,根据距断层距离的大小可将其划分为3个区域;断层对煤储层的作用随着距断层距离的增加而减小,相应的煤储层参数也发生变化。针对不同区域的相关特征,提出了分带压裂法,同时利用“PT”压裂模拟软件对相应区域的压裂参数进行了优化。通过模拟分析与现场试验相结合,针对重点优化的第二带,选取施工排量为5.0~8.5 m^(3)/min,压裂液用量为582.00~810.24 m^(3),加砂强度为3.02~12.00 m^(3)/m,砂比为8.5%~13.9%,可以有效提高煤层气的产量。

In order to develop CBM resources near faults efficiently,based on well sampling test,logging,hydraulic fracturing and other data,combined with"distance measurement"method,the relationships between the stress,coal structure and fracture distribution of coal reservoir in the normal fault and the distance to the fault are analyzed.Through the combination of macro and micro research methods,the conclusion is that the development characteristics of coal reservoirs in normal fault development zone have obvious zonality,and can be divided into three types according to the distance of faults;the effect of faults on coal reservoir decreases with the increase of distance from fault,and the corresponding coal seam parameters change.According to different types of related characteristics,the zone fracturing method is proposed,and the fracturing process in the corresponding zone is optimized by using PT fracturing simulation software.The results are drawn by combining simulation analysis with field test.According to the second zone with key optimization,the fracturing construction displacement is 5.0-8.5 m^(3)/min,the fracturing fluid dosage is 582.00-810.24 m^(3),sand adding strength is 3.02-12.00 m^(3)/m,and sand ratio is 8.5%-13.9%,which can effectively improve the production of CBM.