分形裂缝性页岩气藏多段压裂水平井瞬态压力特征

基于分形理论和连续性假设，考虑页岩气吸附解吸、基质-裂缝窜流等机制，建立分形裂缝性页岩气藏多段压裂水平井试井解释模型，并通过拉氏变换、点源函数及压降叠加原理等方法得到模型的解.绘制无因次压力随时间变化的双对数曲线，研究分形裂缝性页岩气藏多段压裂水平井的压力特征，分析分形指数、分形维数等参数对压力动态的影响.结果表明：分形裂缝性页岩气藏多段压裂水平井的压力动态可划分为7个流动阶段；分形指数越大或分形维数越小，晚期径向流直线段的斜率越大；其它参数对水平井的压力动态也有一定的影响.

Characteristics of Transient Pressure for Multiple Fractured Horizontal Wells in Fractal Fractured Shale Gas Reservoirs

Based on theory of fractal and assumption of continuity, a well test model for multiple fractured horizontal wells in fractal fractured shale gas reservoirs was established in which adsorption, desorption and cross flow between matrix and fractures are considered. Solution of the model was obtained with Laplace transform, point source solution and pressure drop superposition principles. Double logarithmic curves of dimensionless pressure changing over time were obtained. Characteristics of pressure of multiple fractured horizontal well in fractal fractured shale gas reservoirs and influence of parameters, such as fractal index and fractal dimension, on pressure and production curves were analyzed. It shows that the curves can be divided into 7 flow stages. Slope of unstable pressure well-test curves in the middle and late stages is greater with bigger fractal index or smaller fractal dimension.