Quantitative characterization of deep,complex carbonate reservoirs is a signicant challenge due to strong heterogeneity and the ambiguity of conventional geophysical methods.To overcome these challenges,we employed a ...Quantitative characterization of deep,complex carbonate reservoirs is a signicant challenge due to strong heterogeneity and the ambiguity of conventional geophysical methods.To overcome these challenges,we employed a workflow based on a multi-parameter constrained 3D borehole-to-surface electromagnetic(BSEM)simultaneous inversion process.This approach utilizes seismic,well-log,and petrophysical data to constrain the inversion,resulting in 3D resistivity and polarizability volumes.Subsequently,an IP-inclusive oil saturation model(considering the induced polarization effect)was applied to these inverted parameters to derive a quantitative 3D oil saturation(So)volume.The method was applied to an Ordovician carbonate reservoir in Western China.Despite a weak IP response partially masked by a localized high-value anomaly,the constrained inversion resolved the 3D geoelectric structure and revealed a highly heterogeneous,discontinuous"pod-like"distribution of remaining oil.This study constitutes one of the rst applications of the constrained method for quantitative saturation imaging in such a deep,complex setting.The results demonstrate good consistency and were validated by production data:the delineated primary oil-rich favorable zone(F1,dened by So>50%)shows good agreement with the high-saturation intervals encountered by Well X3.This validated workflow provides an eective tool for characterizing heterogeneous carbonate reservoirs where traditional methods prove inadequate.The identied remaining oil enrichment zones(e.g.,F1,F3,F5)serve as actionable targets for optimizing future well placement and eld development.展开更多
基金supported in part by the Science and Technology Project of the China National Petroleum Corporation(CNPC)(Grant No.2023ZZ05)the National Natural Science Foundation of China(Grant No.42474108).
文摘Quantitative characterization of deep,complex carbonate reservoirs is a signicant challenge due to strong heterogeneity and the ambiguity of conventional geophysical methods.To overcome these challenges,we employed a workflow based on a multi-parameter constrained 3D borehole-to-surface electromagnetic(BSEM)simultaneous inversion process.This approach utilizes seismic,well-log,and petrophysical data to constrain the inversion,resulting in 3D resistivity and polarizability volumes.Subsequently,an IP-inclusive oil saturation model(considering the induced polarization effect)was applied to these inverted parameters to derive a quantitative 3D oil saturation(So)volume.The method was applied to an Ordovician carbonate reservoir in Western China.Despite a weak IP response partially masked by a localized high-value anomaly,the constrained inversion resolved the 3D geoelectric structure and revealed a highly heterogeneous,discontinuous"pod-like"distribution of remaining oil.This study constitutes one of the rst applications of the constrained method for quantitative saturation imaging in such a deep,complex setting.The results demonstrate good consistency and were validated by production data:the delineated primary oil-rich favorable zone(F1,dened by So>50%)shows good agreement with the high-saturation intervals encountered by Well X3.This validated workflow provides an eective tool for characterizing heterogeneous carbonate reservoirs where traditional methods prove inadequate.The identied remaining oil enrichment zones(e.g.,F1,F3,F5)serve as actionable targets for optimizing future well placement and eld development.
