目前缺乏简便有效的分析测试压裂压力递减数据的方法，为此开展了测试压裂压力递减特征研究，研究中采用了数值模拟的方法，结果表明：施工停泵后压裂液在地下裂缝和储层将依次经历裂缝延伸、弹性闭合、闭合后拟线性流和闭合后拟径向流4个流动阶段，其压降导数在双对数坐标下会依次呈现1/2斜率、3/2斜率、1/2斜率和0斜率直线段；进一步提出运用井底压降及其导数双对数曲线分析方法，首先诊断出压裂井的各个流动阶段，再分别利用G函数、FL函数和FR函数模型分析获得压裂储层关键参数，如初始地层压力、闭合压力、地层系数、压裂液滤失系数。东海低渗气田某测试压裂井的实例应用证明了提出方法的可靠性和实用性。%Due to the lack of simple and effective pressure decline analysis methods of fracture calibration tests,the pressure decline behavior of a fracture calibration test was investigated. The numerical simulation results show that four flow regimes of the fracturing fluid in formation and fractures,i.e. fracture extension,fracture elastic closure,after-closure linear and radial flow,can be identified. Its differential pressure derivative plot successively shows 1/2 slope,3/2 slope,1/2 slope and 0 slope lines on the log-log coordinate. Further,a fast method which can firstly diagnose the downhole pressure monitoring data in log-log plot was proposed. Then the key parameters of the fracture reservoir will be gotten with the analysis of G function, FL function and FR function,respectively,such as the initial reservoir pressure,closure pressure,formation factor,leakoff coefficient of fracturing fluid etc. The proposed method was applied to a field case in East Sea,China. The results proved that the method is reliable and practical in field application.
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