An Anisotropic Inversion Framework With Hydrocarbon Transport Modeling for Fractured Digital Rock

Abstract In unconventional fractured oil and gas reservoirs, the transport behavior of hydrocarbon fluids often exhibits pronounced heterogeneity and anisotropy. Developing an acoustic inversion method capable of predicting the key parameters of fractured reservoirs has become an urgent need. Most of the existing acoustic inversion models based on assumptions of homogeneous media and simplified hypotheses of hydrocarbon distribution may fail to represent the transport processes in heterogeneous formations accurately. To enhance the accuracy of acoustic inversion, this study integrates digital rock experiments with multiphysics numerical simulations to develop an inversion framework that links medium heterogeneity, fluid transport processes, and acoustic property characterization. In the study, a hydrocarbon transport model is established with multiphase fluid dynamics and incorporated into an acoustic simulation system. With both intrinsic and representative anisotropies of the medium being quantified, a hydrocarbon acoustic inversion template is constructed and further tested on digital rock samples. Results demonstrate that the proposed method effectively predicts key reservoir parameters, including gas saturation and fracture orientation. This inversion framework provides a robust foundation for systematically investigating the hydrocarbon transport processes and the dynamic evolution of petrophysical properties in fractured formations.