基于停泵压降数据的页岩气井单段裂缝参数反演OACSTPCD

Multi-stage fracturing in horizontal wells is a key technology for the effective development of shale gas reservoirs.Accurate evaluation of hydraulic fracture network parameters is an important prerequisite for activities such as the evaluation of fracturing effect,fracturing process optimization and productivity prediction after hydraulic fracturing.Traditional characterizations methods of hydraulic fracture parameters are mainly focus on fracture propagation simulation and on-site monitoring measure,with insufficient exploration and utilization of information from the hydraulic fracturing curves during pumping shut-in stage.This study employs a digital filtering method to mitigate pressure-drop wave artifacts resulting from water hammer during shut-in.It utilizes the fractal fracture characterizing fracture network in shale gas wells,and integrates numerical well testing analysis method to achieve the fracture parameter inversion of each single stage,and establishes a workflow for hydraulic fracture parameters inversion based on the pressure-drop data during shut-in fracturing stage.The outcomes of this study have been effectively applied in the fracturing wells in well area N209 of Changning company,and the inversion results are verified by the fracturing simulation and gas production profile data.This research demonstrates a substantial enhancement in parameters interpretation accuracy achieved through the utilization of single-stage fracture parameters,which is helpful to reveal the reasons for the difference of gas production capacity between stages of horizontal well,the correlation between well productivity and total length of fracture network,fracture surface area is significantly higher than that of stimulated reservoir volume calculated by wide field electromagnetic methods.The correlation between gas rate and total fracture length is the highest at early production period,and the correlation between estimated ultimate recovery(EUR)and fracture surface area is the highest.The total length of fracture network exhibits a strong linear correlation with the cluster average fracturing fluid volume,reflecting the technological advancement of"Fracturing Technology 2.0"in the Changning block shale gas wells.Obtaining single-stage fracture parameters for shale gas wells provides more effective analytical indicators for the analysist of production control factors and the evaluation of hydraulic fracturing effectiveness.