致密气储层直井分层压裂裂缝规模合理性评价

Rationality Evaluation of Fracture Scale for Vertical Well Separated Fracturing in Tight Gas Reservoir

为了实现苏里格致密气目标区块低效井的复产及增产目的,针对直井分层压裂的裂缝规模合理性评价方法问题,运用数值模拟手段和回归公式方法,根据不同的渗透率优化缝长及导流能力,并基于不同含水饱和度对导流能力进行修正,由此得到基于渗透率和含水饱和度的裂缝规模参数。分析结果表明:储层物性差(0.1mD)的储层需要较长裂缝及较低导流能力,储层物性好(1mD)的储层更侧重于短缝及高导流能力;含水饱和度高(0.5)的储层导流能力应适当降低,以增大水的流动阻力,实现控水的目的。实例中通过与问题井的设计参数进行对比,诊断出第2层压裂时导流能力与优化参数相比低了86%,为单井诊断提供了定量、简便的思路和方法,具有较强的现实意义。

In order to achieve the goal of reproducing and increasing production of low efficiency wells in Sulige tight gas target block,it is necessary to study the evaluation method of fracture scale rationality for vertical well fracturing.Using numerical simulation method and regression formula method,the fracture length and conductivity were optimized according to different permeability,and the conductivity was modified according to different water saturation,thus the fracture size parameters based on permeability and water saturation were obtained.The analysis showed that reservoirs with poor reservoir physical properties(0.1 mD)need longer fractures and lower conductivity,reservoirs with good reservoir physical properties(1 mD)focus more on short fractures and high conductivity,reservoir conductivity with high water saturation(0.5)should be reduced appropriately in order to increase the flow resistance of water and achieve the purpose of water control.By comparing with the design parameters of problem wells,it is found that the conductivity of layer 2 fracturing is 86%lower than that of optimization parameters,which provides a quantitative and simple way of thinking and method for single well diagnosis,and this method has a strong practical significance.