深层—超深层海相碳酸盐岩地球物理关键技术OA

To further enhance deep to ultra-deep seismic exploration capabilities and address the challenges of strong heterogeneity and low seismic prediction accuracy in carbonate reservoirs,a deep and thorough investigation was made on key technologies,including fine identification of subtle structural traps,micro-paleogeomorphology analysis based on intelligent fine layer correlation,and high-resolution quantitative characterization of heterogeneous reservoirs.The supporting technologies have been developed and widely applied to the Sinian Dengying Formation and Permian Maokou Formation in Sichuan Basin.Results show that(i)prestack depth migration based on fine velocity modeling can effectively solve the problem of inaccurate energy positioning caused by overlying gypsum-salt layers;(ii)micro-paleogeomorphology analysis based on the optimal basis wavelet time-frequency decomposition improves the identifiability of internal layer interfaces by utilizing the abundant frequency-domain information of seismic data;and(iii)high-resolution quantitative characterization of heterogeneous reservoirs driven by waveforms effectively addresses the issue of low accuracy in vertical and lateral quantitative prediction of deep reservoirs.It is conclude that the proposed technologies improve the prediction accuracy of subtle structures,micro-paleo geomorphology,and heterogeneous reservoirs,demonstrating good stability and reliability.Also,these technologies have supported the establishment of a trillion-cubic-meter-scale gas area in the Penglai area of the northern slope in central Sichuan Basin and ensured that 100%of the wells drilled in the platform-margin zone of the Permian Maokou Formation in central Sichuan Basin encountered high-quality reservoirs.The research findings provide reference for the exploration and development of similar complex carbonate reservoirs in other basins in China.