Seismic reflection pattern and attribute analysis as a tool for defining reservoir architecture in ‘SABALO’ field, deepwater Niger Delta

Abstract

AbstractAn accurate definition of environment of sediment deposition is a sine qua non for characterizing and providing measures for enhancing hydrocarbon reservoirs. Consequently, this study is aimed at determining the sub-environment of deposition and architecture of two reservoirs: S1000 and S2000 reservoirs, in ‘SABALO’ field, deep offshore Niger Delta. In addition, the study is imperative in order to assess reservoir properties such as: geometry, connectivity and continuity, which are important for exploration and reservoir management. In this study, we integrated well logs from six (6) wells and 3D-seismic data (near and far angle stack) for seismic stratigraphic studies. Four major seismic sequences with their corresponding facies units were recognized by analysis of reflection terminations, seismic parameters and external geometry. The reservoirs of interest are within the seismic sequence one containing facies units: SF1A and SF1B. Both reservoirs were delineated to be structurally and stratigraphically controlled. This implies a combinational trapping system at the reservoir level. Also, hydrocarbons in the reservoir were confirmed to be down to reservoir base. Integrated study of the seismic and well logs shows that the two identified reservoirs, S1000 and S2000, were defined to be weakly confined channel complex with an area of 50 km2 and 78 km2, respectively. Their connectivity was defined to be loosely amalgamated and highly amalgamated, respectively. The results of this paper are essential to develop the reservoirs by utilizing the information of their geometry, connectivity and continuity.