Prestack seismic prediction technique for ultra-deep carbonate reservoirs in Shunbei field

For ultra-deep carbonate reservoirs with strong heterogeneity and complex hydrocarbon charge in Shunbei field, this study makes seismic response analysis and reservoir-characteristics-constrained AVO inversion. Using log, core, and seismic data, three reflection types and AVO characteristics of reservoirs in Shunbei field are investigated. Then, forward modeling is conducted on reservoirs containing different fluids, demonstrating that gas-bearing reservoirs induce significant changes in seismic amplitude and AVO response. This provides the theoretical basis for AVO inversion-based reservoir prediction in Shunbei field. Next, the stochastic model capturing the reflectivity variation of underground reservoirs is established, and the reservoir-characteristics-constrained AVO equation is derived, enabling the prestack inversion to obtain fluid-sensitive parameters. Application of this proposed technique in Shunbei field demonstrates the AVO inversion results in agreement with actual drilling results, proving it reliable for identifying ultra-deep carbonate reservoirs and characterizing hydrocarbon accumulations in Shunbei field.