页岩气储层压裂水平井三线性渗流模型研究

摘要

Shale gas reservoirs with plenty of natural fractures and nano-scale poreshave a variety of seepage patterns,fractured horizontal well has become the key production method,in which establishment and solution of percolation mathematical model is of a strong theoretical and practical value. Drawing lessons from the existing three linear seepage model,we re-designed the composition of the model,and established seepage mathematical model including adsorption and desorption. The capacity formula of single well production of fracturing shale gas reservoir horizontal well and the bottom hole pressure formula are deduced with the help of dimensionless and Laplace transform. Then we applied the results to the analysis of the influence factors in the process of single well production. The results show thatthe formulae obtained by the simplified model can calculate and predict the changes of shale gas production with convenience and accuracy,and also provide the optimization of design parameters for fracturing design.%具有天然裂缝发育及纳米级孔隙的页岩气储层渗流具有多种模式，压裂水平井开发模式已成为页岩气藏主要开发模式，渗流数学模型的建立与求解具有很强的理论意义和现实价值。借鉴已有的三线性渗流模型思路，重新设计了模型的构成，并建立了包括解吸吸附的渗流数学模型，借助无因次化及拉普拉斯变换推导出单井压裂水平井页岩气藏的产能公式和井底压力公式，最后，应用得到的结果进行了单井生产过程中影响因素的分析。通过研究与应用表明，由该简化模型得到的公式能方便而且准确地计算并预测页岩气的产量变化，而且对于压裂设计也可提供设计参数的优化分析方法。