注水开发中储层裂缝失稳扩展的力学机理

Study of the Mechanism of Crack Instability Propagation in Reservoir during Oil Developing

油井暴性水淹是裂缝性砂岩油田开发的普遍特征,其中很多是由注水引起裂缝失稳扩展所致。本文根据砂岩储层的物理力学特征,运用断裂力学理论,给出了储层裂缝的应力强度因子的计算方法,定量地分析了开发过程中储层裂缝失稳扩展的判据、裂纹扩展方向。对于合理确定注水压力及井网的合理布置,防治水窜及暴性水淹等具有重要的指导意义。

Volcanically water flooding of oil well is very ubiquitous during oil developing. It is the result of crack instability propagation in the reservoir. Using the LFEM theory, the author provided the computing method of stress strength factor of crack and the criteria of crack instability propagation and propagation angle. The content is very useful in the well arrangement and design of water flooding pressure. It is of significance in preventing volcanically water flooding of oil well.