【摘要】 在油气田开发过程中,地应力受注水、火烧油层等因素的影响状态发生改变,对油气生产有较大的影响。以地下流固耦合理论为基础,建立了考虑油水井注采关系的地应力场的数学模型,应用有限元方法考虑孔隙压力变化的三维应力场有限元数值模拟;应用组合网格法解决地层尺寸和井口尺寸的巨大差异造成的计算困难;以油田地质和开发实际数据作为计算输入,通过三维地应力场数值模拟系统计算得出油田注采开发时的流体压力、饱和度、固体变形以及应力场在空间的分布和时间上的动态变化情况;其结果为油田开发采取适当措施,达到最优开采目的提供可靠的依据,同时也为后期开发调整、重复压裂、套管损坏预测等提供理论依据。更多还原

【Abstract】 The state of terrestrial stress changes because of the effects such as water injection and in-situ combustion during the exploitation in the oil and natural gas fields, which influence the yield of oil-gas relatively seriously. In this paper, based on the theory of liquid-solid coupling, the mathematical model of the terrestrial stress field is established which takes the pour-pluck relations into consideration. The finite element model is developed in three dimensional stress field with the pore pressure changing by using the finite element method, the dyscalculia with the discrepancy between the stratum size and the mouth of a well size is solved by using the method of composite grid. The input is geologic and practical exploitative data, fluid pressure, saturation, solid distortion and the spatial distribution and the change with time of stress field are calculated through three-dimensional stress field numerical simulation system. The result offers reliable basis for using appropriate measures to optimum development; meanwhile,it offers theoretical basis for exploitation adjustment, refracturing, forecasting the damage of casing etc. in anaphase.更多还原