考虑井筒损失的低渗透压裂水平井产能研究

Productivity analysis of a fractured horizontal well in low-permeability gas reservoirs considering the pressure loss in wellbore

对于低渗气藏,采用水平井水力压裂技术进行开采是一种常用手段。而大部分加砂压裂结果会产生有限导流裂缝,对这种水平井的产能预测非常重要。通过保角变换方法,将水平裂缝气井的渗流问题转换为相对简单的单向渗流问题,然后以裂缝内的流体为不稳定流动为基础,导出考虑水平井筒中存在压降损失情况下的有限导流裂缝水平井的产能公式。通过实例验证,表明井筒磨损确实会影响低渗气藏压裂水平井的产能。该方法较简单,便于现场应用。

Fracturing technology is a common method to regain production capacity in hori- zontal wells of a low-permeability gas reservoir. Most sand fracturing will generate finite con- ductivity fractures, it is essential to forecast the productivity of the particular kind of hori- zontal well. According to the conformal transformation principle, the problem of hydraulically fractured gas well flow is converted into a one-way flow problem which is relative easier to solve. Based on the unstable folw theory, with the influence of pressure drop in horizontal wellbore, the computation formula for productivity in hydraulically fractured horizontal wells is deduced. The result show that the pressure loss in wellbore does have influence on the productivity. This method is relative simple and can be put into practice.