巴什基奇克组地层岩石力学及地应力特征

Investigation of Rock Mechanics and In-situ Stress Characteristics of Bashijiqike Formation

为深入认识克深地区巴什基奇克组地层岩石力学及地应力特征,以室内力学试验结果及压裂分析结果为依据,采用点-线-面、体逐步递进的技术思路开展研究区岩石力学参数三维空间展布及三维地应力反演分析。研究结果表明:地层弹性模量及抗压强度在分析区域西南角以及南部边缘相对较高,其余大部分区域相对较低。地层泊松比主要分布在区域西南角以及南部边缘泊松比相对较低,其余部分相对较高,弹性模量与抗压强度的分布规律相近,与泊松比分布规律相反。巴什基奇克组地层地应力状态以潜在走滑型为主,垂向主应力分布范围则为130.0~196.0 MPa,水平最大主应力分布范围为160.0~210.0 MPa,水平最小主应力平面分布范围则为110.0~175.0 MPa,断裂带附近主应力的大小变化较大,形成快速的应力变化带。断层下盘应力集中程度大,应力水平高,断层上盘呈现低应力水平,形成显著的低应力区。埋深对最大主应力影响显著,构造高点地应力水平相对较低。巴什基奇克组地层顶面地应力方位以近NS向为主,水平最大主应力方位范围为345°~25°。

In order to deeply understand the rock mechanics and in-situ stress characteristics of Bashijiqik formation in Keshen area, based on the results of indoor mechanical tests and field fracturing data analyses, the three-dimensional spatial distribution research of rock mechanics parameters and the three-dimensional in-situ stress inversion analysis in the study area were carried out according to the proposed progressive technical thinking of spot-line-face and body, which including well seismic joint analysis. The results show that the elastic modulus and compressive strength of Bashijiquike formation are relatively high in the southwest corner and the southern edge in the analysis area, and relatively low in most other areas. The distribution of Poisson’s ratio is just opposite. The in-situ stress type in Bshijiqike formation is mainly potential strike slip type. The distribution range of vertical principal stress is 130.0~196.0 MPa, the distribution range of horizontal maximum principal stress is 160.0~210.0 MPa, and the distribution range of horizontal minimum principal stress is 110.0~175.0 MPa in Bashijiqike formation. Within the fault, there is a significant low stress area. Near the edge of the fault, there is a significant stress concentration area and a rapid change zone of stress. The in-situ stress direction of the top surface in Bashijiqik formation is mainly in the near NS direction, and the maximum horizontal principal stress direction ranges from 345°to 25°.