页岩气藏压裂水平井三线性流试井模型研究

Well test model of trilinear flow for fractured horizontal wells in shale gas reservoirs

为高效合理的开发页岩气藏,该文提出了页岩气藏压裂水平井三线性渗流模型。此模型考虑了页岩气吸附解吸和扩散机理,运用Laplace变换和Duhamel原理,最终求得考虑井筒储存和表皮效应的压裂水平井Laplace空间无因次井底压力解。并通过Stehfest数值反演,绘制相应的无因次压力及导数特征曲线,对其无因次压力导数特征曲线进行了流动阶段的划分和影响因素分析。研究结果有利于提高对页岩气藏压裂井渗流规律的认识,为开发页岩气藏提供理论支持。

In order to develop shale gas reservoir reasonably and efficiently, this paper presents an analytical trilinear seepage flow model of horizontal fractured well .This model considers the adsorption, desorption and diffusion mechanism of shale gas and applys the principle of Laplace transposition and Duhamel. The Laplace space solution of dimensionless bottom hole pressure is achieved considering wellbore storage and skin effect. Type curves of dimensionless pressure and derivative are plotted with Stehfest algorithm and the different flow regimes and factors of type curves are identified. The results are beneficial to improve the understanding of seepage flow mechanism of fractured well in shale gas reservoir and provides the theoretical support for the high-efficiency development of shale gas reservoirs employing horizontal fractured wells.