An inverse method for the heterogeneous fracture networks of fractured shale gas/coalbed methane wells with well-testing
Fracture networks inversion for shale gas/coalbed methane fractured wells is the basis for de-velopment-adjustment-deployment,scheme optimization and efficiency evaluation of enhanced gas re-covery.However,existing well-testing methods face challenges in efficient fracture inversion considering limitations from:abundant natural fractures development in the formation,complex pattern of the frac-tured networks and profound heterogeneities.This study established a multi-media seepage mathematical model of fractured wells based on the characterization of shale gas/coalbed methane occurrence,nonlin-ear flow mechanism and varied scales of heterogeneous fracture networks.Afterward,the high-efficient numerical solution of the model was achieved based on the improved Green's element method,and the dynamic pressure response characteristics of fractured shale gas/coalbed methane wells were obtained.Then the influence law between flow phases and heterogeneous fracture network parameters was clarified.At last,a well-testing data analysis method for inversing the heterogeneous fracture network parameters was raised and relevant applications were applied to a field case.The results showed that the pressure dynamic response of fractured shale gas/coalbed methane well mainly consisted 6 flow stages.The pseudo-steady flow stage would appear in the modified zone if reservoir zoning were considered.Early bilinear and linear flow phases were primarily affected by fracture conductivity,while phases be-fore the boundary-dominated flow phase were heavily impacted by fracture length.Fracture network morphology's dynamic response under pressure could be weak if fracture length equaled fracture stages,then other data should be introduced to obtain the heterogeneity of the fracture networks,such as geolo-gy,fracturing,microseismic monitoring data,etc.By combining fracture network modeling,dynamic simulation,and characteristic line/curve fitting,the proposed well-testing analysis method can be used to interpret heterogeneous fracture networks in fractured wells.In this study,basic theory and technical support are provided for the research of shale gas/coalbed methane reservoir engineering.
万方数据
维普
