NAPE March Technical Meeting

Seismic Lithofacies Characterization of Turbidite Reservoirs: A Case Study from a Deep Offshore Field in the Niger Delta

Lithofacies characterization is commonly used in reservoir model building, well planning, placement, and reservoir management because facies majorly control porosity and permeability. Seismic lithofacies characterization in seismic space is highly dependent on significant variations in rock physics behavior and seismic properties between lithofacies. However, the heterogeneous nature of turbidites in deepwater settings, linked principally to successive sedimentation, erosional episodes, and tectonics complicate this dependency due to significant overlaps in rock physics behavior. This technical presentation highlights a Niger Delta case study showing the application of rock physics-based decoupling in the lithofacies characterization of deepwater turbidite reservoirs. The approach utilized lithofacies sensitivities from inverted IP (P-impedance) and Vp/Vs (P-velocity/S-velocity) attributes derived from ocean bottom nodes (OBN) seismic data and was aimed at minimizing uncertainties in the predictiveness of lithofacies probability cubes due to facies overlap. The seismic characterization resulted in robust lithofacies cubes used for reservoir model building, well design/placement, and reservoir management of the field.
Keywords: Deepwater, Turbidite reservoirs, Lithofacies, Seismic lithofacies characterization, Inverted attributes, and Rock physics decoupling.