Application and effect of converted wave seismic imaging technology in carbonate reservoir exploration in southern Sichuan

A comprehensive statics technique for converted wave data was adopted effectively to solve the problems of low signal-to-noise ratio, serious statics and imaging difficulties in fracturedcarbonate reservoir in the study survey of southern Sichuan Basin. Thisstatics technique combinedthe surfave wave dispersion curves in version, common-detection-point stackingand cross-correlating method and nonlinear global optimization method for residual statics together.The converted wave prestack time migration technique for VTI anisotropic medium was appliedto solve the complex imaging problem, which wasbased on the establishment of migration velocity models and anisotropic parameter models for both PP and converted wave data.The processing results showed that the imaging quality of converted wave data with low signal to noise ratiowas improvedeffectively, with the diffraction energy beingfocused, the far offset imaging gathers being flattenedand the target layersbeing migrated accurately.The final two migration profiles of PP wave and converted wave data correlated with each other clearly with the consistent corresponding features, and the target layer is clearly imigrated, which built a good foundation for gas and water identification and fractured carbonate reservoir detection in the target formaton.