Application of Seismic Multi-attribute Fusion Technology in Carbonate Reservoir Prediction in a Prospective Area of Kazakhstan

The marine carbonate reservoirs in the T exploration area, situated in the central eastern margin of the Pre-Caspian Basin, are characterized by complex lithology, rapid lateral variations in petrophysical properties, and poor reservoir continuity. Conventional single-attribute reservoir prediction methods have shown limited applicability in this area, making it challenging to identify favorable reservoirs. This study proposes a novel multi-attribute fusion approach for reservoir prediction, which integrates lithology, petrophysical properties, and hydrocarbon indicators based on seismic attributes sensitive to different parameters, enabling precise reservoir prediction under multi-parameter constraints. The workflow includes: (1) lithological identification of limestone reservoirs through conventional acoustic impedance inversion; (2) screening of medium-to-high porosity, high-quality limestone reservoirs using porosity inversion; and (3) proportional fusion of acoustic impedance inversion, porosity inversion, and hydrocarbon detection results to delineate prospective zones with favorable porosity and hydrocarbon potential. Application of this method in the T exploration area successfully predicted 305 km2 of high-quality carbonate reservoirs, achieving an 84.3% consistency rate with drilling results. The approach has guided the deployment of multiple exploration and appraisal wells, resulting in high-yield oil and gas discoveries. We provide a robust technical solution for reservoir prediction in complex carbonate settings and demonstrates significant potential for application in similar exploration areas.