低渗透油田水力压裂垂直缝增产效果的数值模拟评价

The Numerical Simulation Method for Evaluating Effect of Vertical Fracture of Hydraulic Fracturing in Low-Permeability Reservoir

李留仁,余国清,张　鹏

Li Liuren, Yu Guoqing, Zhang Peng

西安石油学院,中原石油勘探局

Xi’an Petroleum Institute , Shanxi 710065 , P. R. China

用三维三相全组份对低渗透油田水力压裂垂直缝井的自然能量衰竭式开采过程进行了预测,并与不压裂的自然能量衰竭式开采过程进行了比较。结果表明,考察水力压裂垂直缝增产效果应从考察井的瞬时产量的变化和考察动态生产过程两个方面进行,水力压裂垂直缝在前期提高了井的产量,随着时间的推移其效果逐渐减弱至消失,这不仅是传统上认为的裂缝闭合造成的结果,而且是因为改变了渗流场造成的;水力压裂垂直缝提高了开采速度,但对采收率的影响微乎其微,文中利用物质平衡方法对其进行了详细分析。

The hydraulic fracturing is a common technique for improving the productivity of low-permeability fields. Stimulation multiple methods commonly used to evaluate the incremental effect is a static method , and is unable to take the time affection on the production process into consideration. Some researchers studied the effect of hydraulic fracturing by the numeric method of dimensionless equation. This article predicts the natural depletion process of low permeability wells with the vertical fracture of hydraufrac , and correlate to the natural producing process of the non-fractured wells by using 3D-3P full compositional simulation. It shows that the incremental effect of the hydraufrac vertical fracture should be considered ,and the producing process and the production changes behaviorally and timely. The hydraufrac vertical f racture increased the well production only in early period. This is not only due to the affection of traditionally considered the fracture closing , but also because of the changed percolation zone ; the hydraufrac vertical fracture improves the recovery rate , but affects the recovery weakly. It’s analysis is given with material balance method.