基于反褶积的地热井放喷反演及产能预测研究

RESEARCH OF OPEN FLOW TEST INVERSION AND PRODUCTION CAPACITY PREDICTION OF GEOTHERMAL WELL WITH DECONVOLUTION

为分析地热井放喷试验获得的变流量下的压力数据,根据Duhamel原理将变流量时的井底压力表示为单位流量下的压力和流量的褶积,使用反褶积方法计算出单位流量下的压力数据,再使用压力及导数试井分析方法反演出热储的渗透率等流动参数,从而建立地热井放喷试验数据反演的理论和方法,并使用反演出的参数求解渗流方程得到流量的变化规律。最后使用该方法分析四川某地热井的放喷试验数据并进行产能预测。

A new approach was presented to address the difficulty of analyzing both varying pressure and flow rate data obtained over open flow test of geothermal well. The well bottom pressure under varying flow rate was expressed as the convolution of flow rate and pressure under unit flow rate according to the Duhamel theory. The deconvolution method was used to calculate pressure data under unit flow rate, then pressure and derivative Test Well Analysis Method was used to derive inversely the reservoir permeability etc. parameters. Thus the theory and method of open flow test data inversion of geothermal well was set up, the parameters obtained from inversion were used to solve seepage equation and get variation of flow rate. Finally, the presented approach was used to analyze the open flow test data of certain geothermal well in Sichuan and predict production capacity.