摘要
相邻的沉积微相不仅地应力大小不同,地应力方向也存在较大差异。利用有限单元法,通过改变不同的边界条件(包括河道介质和周围岩体的弹性模量、泊松比,河道走向与区域主应力方向夹角及边界应力比),对河道砂体地应力的影响因素进行分析。模拟结果表明,相比于河道周围岩体和区域地应力特征,不同的边界条件对河道砂体地应力大小和方向的改变程度很大,其中河道砂体与周围岩体的弹性模量比、河道走向与区域主应力方向夹角及边界应力比是影响河道砂体现今地应力方向和大小的主要因素。研究结果可以为不同沉积微相下进行人工压裂和井网部署提供参考依据。
With the further geological exploration, it is showed that different values and directioris of in-situ stress are appeared in the adjacent sedimentary facies by a mass of production test data. By changing different boundary conditions （including the elasticity modulus and Poisson＇ s ratio of channel and surrounding rock, the inclined angle between channel direction and the orientation of the regional principal stress and boundary stress ratio） , the influence factors of the geostress in the channel sandstone are analyzed in finite element method. It is showed that the stress values and directions of the channel sandstone change seriously under the influences of different boundary conditions, compared with the in-situ stress characteristics in the surrounding rocks and region. The influence factors on the present stress of the channel sandstone are mainly the elastic modular ratio of channel to the surrounding rocks, the inclined angle between channel direction and the orientation of the regional principal stress and boundary stress ratio. The result could provide references for artificial fracturing and well network deployment in different sedimentary microfacies.
出处
《地质力学学报》
CSCD
2014年第2期149-158,共10页
Journal of Geomechanics
关键词
地应力
河道砂体
有限元法
影响因素
ground stress
channel sandstone
finite element method
influence factors
