重复压裂气井三维诱导应力场数学模型

重复压裂新裂缝的重新定向分析是具有相当难度和应用价值的核心问题,也是制约重复压裂优化设计的关键。重复压裂产生的裂缝方向取决于地应力状态,垂直裂缝井重复压裂前储层中的应力分布,尤其是水平主应力方向控制着重复压裂裂缝的起裂方位和延伸方向。系统研究了垂直裂缝井重复压裂前应力场的分布特征及影响应力大小和方向变化的主要因素,在此基础上应用弹性力学、流固耦合、孔隙弹性理论等建立了重复压裂气井诱导应力场的数学模型,实现了垂直裂缝气井重复压裂前应力场的定量分析与模拟。

Mathematical Model of 3D Induced Stress Field in Refracturing Gas Well

The refracturing reorientation is fairly difficult and most important in refracturing. The refracture orientation depends on the stress field in the vertically-fractured well. The stress field, especially the horizontal principal stress orientation in the vertically-fractured well determines the azimuth of refracture creation and refracture propagation. The paper study systematically the stress characteristics of vertically-fractured gas well and the main factors affecting the change of stress value and the stress orientation. Using the theory of elasticity mechanics and fluid-solid coupling and poroelastic, we have set up the mathematical model of induced stress of refracturing gas well to quantitatively analyze and simulate stress filed before refracturing for vertically-fractured gas well.