青西油田构造应力场数值模拟及裂缝分布预测

青西油田主要为裂缝性储集，裂缝是油气的主要储集空间和控制油富集的因素，为了更好地预测裂缝的分布区域和发育程度，用有限元方法对主要储集层下沟组一段和下沟组三段喜马拉雅运动期进行了构告应力场数值模拟。根据构造演化、岩心和测井资料确定青西油田储集层有效裂缝的主要类型为低角度斜交缝、层间缝和少量高角度缝。应用构造应力场数值模拟结果，根据库伦-摩尔破裂准则，进行了构造裂缝预测。预测结果表明，研究区裂缝普遍发育，发育程度较高地地区主要位于油田的东部和南部，而高产井均位于裂缝发育程度较高的地区。因此，裂缝发育程度高的地区是较好的油气勘探开发区。

Numerical Simulation of Tectonic Stress Field and Prediction of Fracture Distribution in Qingxi Oilfield

Qingxi oilfield is a fractured reservoir. The fractures are the main oil-gas reservoir space and controlling factors for petroleum enrichment. To well predict the distribution area and development extent, finite element method (FEM) is applied to make numerical simulation of tectonic stress field for No.1 and No.3 members of Xiagou formation. According to the data of structural evolution, core and well logging, this paper suggests that the effective fractures of Qingxi reservoir were mainly formed in period of Himalayan orogeny. The main types of the fractures are dip-crossing fracture with low angle, interlayer fracture and few high angle fractures. According to the numerical simulation results and Coulomb-Mohr's criterion of fracture, these structural fractures are predicted. The result shows that the fractures are generally developed in this studied area. The major fractured areas are located in eastern and southern Qingxi oilfield. And the high-yielding wells are all situated at the well fractures areas. So these areas are favorable ones for oil-gas exploration and development.