Application of Frequency Attenuation Hydrocarbon Detection Method in Ultra-Deep Carbonate Reservoir Exploration

Based on the biphasic medium theory, this paper proposes a hydrocarbon detection method that integrates multi-scale frequency-varying characteristics, enhancing the hydrocarbon response features in seismic data by optimizing sensitive attributes. Model simulations and actual data validation demonstrate significant differences in low-frequency energy attenuation gradients between oil-bearing and water-bearing reservoirs: oil layers exhibit enhanced high-frequency components, while water layers are dominated by low-frequency energy. In practical applications, this method effectively delineates the oil-water boundaries of structural hydrocarbon reservoirs in the C9 block of the Qaidam Basin by extracting frequency attenuation gradient attributes. The planar prediction results show high consistency with drilling interpretations, revealing the oil-bearing potential of reservoirs in structural slope areas. Compared to traditional pre-stack inversion techniques, this method significantly improves the accuracy of oil-water differentiation identification, providing new technical support for ultra-deep carbonate reservoir exploration.