Enhancing litho-fluid discrimination in Niger Delta reservoirs using TCCA-optimized Poisson Impedance

Traditional seismic inversion often struggles to differentiate sandstone reservoirs from surrounding shales in the Niger Delta due to overlapping P- and S-impedance contrast. This study utilizes Poisson Impedance (PI), optimized through the Target Correlation Coefficient Analysis (TCCA) method, to overcome these limitations. By iteratively correlating the PI curve with Gamma Ray (GR) and Water Saturation (Sw) logs, optimal rotation factors, c values were determined to isolate lithological and fluid properties, such that the value which gave the maximum correlation coefficient for GR and Sw were used to derive two new attributes namely Lithology impedance (LI) and Fluid Impedance (FI) respectively. The results identified an optimal c value of 1.324 for Lithology Impedance (LI) (max correlation: 0.758) and 1.296 for Fluid Impedance (FI) (max correlation: 0.633). Cross-plot analysis of these derived attributes successfully separated sand-shale facies and identified hydrocarbon-bearing zones. Application to pre-stack seismic data produced LI and FI volumes consistent with well-log observations, indicating that TCCA-derived Poisson Impedance is an effective tool for high-resolution reservoir characterization in complex deltaic environments.