用高能气体压裂模型研究裂缝条数

The Study of Number of Fractures Using High Energy Gas Fracturing Model

王爱华 李璗 赵锋洛
　　　

西安石油学院压裂中心，中原石油勘探局采油五厂

High Energy Gas Fracturing (HEGF) Research Center , Xi’an Petroleum Institute ,Shanxi 710065 ,P. R. China

采用由火药燃烧规律方程、考虑了压缩性和水力阻力的井内流体运动方程、孔眼节流方程、驱替液体进入地层和火药气流入随之形成并延伸的裂缝的方程等组成的微分方程组来模拟压裂弹在井内的工作过程,计算可得不同地质条件、不同药量所压出的裂缝长度和宽度随时间变化的规律,从而求出裂缝生长速度。根据裂缝尖端生长速度不能超过该岩石传播横波速度的一半来确定裂缝条数。

Differential equations set ,including the borehole fluid movement equation , the kinetic equation of fluid in the well considering compressibility and hydraulic resistance ,the motional equation of liquid and gas pushed into formation to create fracture and extend it ,can be used to simulate the working process of gunpowder pressure generator. The length and width of fracture varying with time can be obtained under different geologic conditions with different explosive quantities. Then, the number of fractures are turnned out according to the growing velocity of the tip of fracture.