页岩气立体开发井组压后取心裂缝双向溯源方法及井间连通特征OA

There is no method for directly verifying the fracture sources and propagation patterns in stereoscopic development well pads of shale gas,and conventional monitoring and numerical simulation methods struggle to accurately determine the corresponding relationships of fracture propagation paths to stages and clusters,thereby restricting the detailed evaluation of and parameter optimization of fracture networks.Based on the CT scanning,core observation,image logging,acoustic remote detection,and fracturing operation parameters of the stereoscopic development well pad A in the Jiaoshiba Block of the Fuling Shale Gas Field,this paper establishes a source tracing method integrating hydraulic fracture identification and classification,reverse discrimination based on cored fractures,forward deduction from perforation clusters,and two-way consistency verification.The following results are obtained.First,based on fracture occurrence and morphology,and their relationships with the maximum horizontal principal stress,the hydraulic fractures are classified into three types:straight propagating fractures,self-deflecting propagating fractures,and multi-diverting/branching hydraulic fractures.Second,a total of 2 331 hydraulic fractures are identified in the study area,among which,1 542 have a relatively certain source,accounting for 66.2%.Third,the data reveals that the formation of hydraulic fractures is not a simple process of"one perforation cluster corresponding to one major fracture",but rather resembles a set of locally dense,nearly parallel fracture groups induced by a single cluster.Fourth,the vertical connectivity of the reservoir exhibits significant stratification-dependent variations.The upper and middle gas layers show favorable connectivity,whereas the lower gas layer,subject to stress shielding effect,exhibits notably weaker inter-well connectivity.In conclusion,this method enables the maximum-probability post-frac identification and source homing of hydraulic fractures,providing a robust basis for fracture network evaluation,layer connectivity analysis,and fracturing parameter optimization of shale gas well pads.