Application of curve reconstruction technology in seismic inversion of carbonate reservoirs

Abstract The development layer of K oilfield in the Pre-Caspian Basin is Carboniferous carbonate rock layer. The reservoir interval displays pronounced lithofacies variability, the lateral variation is large, the heterogeneity is strong, and the pre-stack gather data is lacking in this area. Only post-stack seismic inversion technology is difficult to distinguish different lithologies, which adversely impacts the forecasting accuracy of carbonate reservoirs and hinders the identification and prioritization of prospective zones. In view of the above difficulties, through rock physics analysis, the shear wave velocity and P-wave velocity ratio ‘ logging curve ’ are reconstructed, and the elastic parameter characteristics of different lithologies are clarified, which provides basic data for post-stack inversion and reservoir prediction. Building upon rock property analysis, a sensitivity assessment of the elastic parameters was undertaken, and the technical scheme for predicting the distribution of Carbonate deposits in the KT-I layer of the Carboniferous period was established. Leveraging the three-dimensional seismic measurements of the exploration block, comprehensive seismic inversion analysis enabled effective prediction of Carboniferous reservoirs, and the carbonate reservoir thickness distribution of the Carboniferous KT-I hydrocarbon-bearing formation was effectively characterized in the target area. According to the research results, it is predicted that the carbonate reservoirs in the northwest of the work area are the most developed and determined to be the most favorable target area.