Prestack seismic inversion of fluid factors in fractured reservoirs based on the global adaptive MCMC algorithm
Fractured reservoirs typically exhibit anisotropic characteristics,and their fractures show different seismic responses when filled with fluids.Accurate identification of fluids in fractured reservoirs plays a significant role in indicating the hydraulic fracturing process in the late hydrocarbon exploration and production stage.This study adopted the concepts of normal and tangential fracture qua-si-weaknesses and constructed a new indicative factor for fluids in fractures.Combining the linear slip theory,this study derived the e-lastic stiffness matrix expression of the fracture-induced HTI medium.Based on the scattering theory and the Born approximation equa-tion,this study derived the linearized P-wave incident anisotropic reflection coefficient equation for the weakly contrasted interface.Mo-reover,this study proposed an improved global adaptive MCMC algorithm by introducing the adaptation strategy into the MCMC algo-rithm.The results show that:(1)In the absence of noise,the model testing results were highly consistent with the log data,with a consis-tency degree of above 90%;(2)The inversion results of the actual data aligned closely with the log interpretation results,and hydrocar-bons were discovered through drilling in the target interval.As indicated by the results of model testing and actual data application in a study area in Southwest China,the prestack seismic inversion of fluid factors in fractured reservoirs,yielding highly consistent results with log interpretation data,demonstrates certain reliability and applicability and thus can achieve accurate fluid identification and hy-draulic fracturing indication.
万方数据
维普
