凝析气藏压裂返排参数对气井产能的影响

Influences of flowback parameters on gas well production during the condensate gas reservoir fracturing

为了确定低渗透凝析气藏压裂后的最佳返排速率,首先建立压裂返排物理模型,然后通过保角变换,将压裂后形成的椭圆形流动区域转化为圆形流动区域,利用平面径向流产能公式确定压裂后气井的产能。利用该产能模型进行实例分析,发现凝析气藏压裂返排速率影响气井的产能,返排速率过快或过慢都会降低气井的产能。中原油田白庙断块沙三中亚段以100m3/d左右的初始返排速率返排,压裂后将获得最高产能15 000m3/d。

In order to calculate the optimal flowback rate during fracturing of low permeability condensate gas reservoir, a flowback physical model of fracturing is established, the conformal transformation method is used to transform the elliptic flow region formed during the fracturing to circular flow region, then the radial flow productivity formula is used to calculate the gas well productivity after the fracturing. Field analysis with the productivity model reveals that the gas productivity is affected by flowback rate, a flow rate either lower or higher than the optimal one may decrease the gas well productivity. In the middle of 3^rd member of Shahejie Formation, Baimiao Block, Zhongyuan Olifield, Sinopec, the optimal productivity will be 15000 m^3/d with the optimal flowback rate of 100 m^3/d.