川西坳陷盐井沟构造沙溪庙组现今地应力方向

Current terrestrial stress direction of the Shaximiao Formation in the Yanjinggou Structure of the West Sichuan Depression

川西坳陷盐井沟构造沙溪庙组属于低孔、低渗储层,现今地应力方向的研究是该区人工压裂获效的基础。通过追踪川西坳陷历年天然地震P波方向,结合相邻构造现今地应力方向的研究成果,对研究区现今地应力方向进行了分析和判断;在此基础上,通过单井取心古地磁定向实验和波速各向异性实验,进行现今最大主应力方向的测定和计算。结果发现,计算获得的现今地应力方向与天然地震和相邻构造上地应力方向具有一致性。综合各种资料及实验分析成果,判定研究区沙溪庙组现今地应力方向为北西向。

Reservoir of the Shaximiao Formation in the West Siehuan Depression is of low porosity and permeability. To know the current terrestrial stress direction is the basis for effective fracturing in this area. Through tracking down the P-wave direction of natural earthquakes in the West Sichuan Depression over the years and referring to researches on current terrestrial stress direction in adjacent structures, the current terrestrial stress direction of the study area is analyzed and predicted. By the paleomagnetic directional experiments and velocity anisotropy experiment with single-well core, the maximum principal stress direction is measured and calculated. The results show that the calculated current terrestrial stress direction is consistent with that of the adjacent structures. Eventually, according to various data and experimental results, the current terrestrial stress direction of the Shaximiao Formation in the study area is determined to be a NW direction.