Stratigraphic Trap Configurations, Seismic Sequence and Facies Analyses of the ‘Ekwai’ Field: Implications for Hydrocarbon Exploration In The Niger Delta

Abstract

Stratigraphic traps have become increasingly important exploration targets in the mature Niger Delta Basin because of the progressive depletion of conventional structural traps. This study utilized three-dimensional (3-D) seismic data, wireline logs, checkshot surveys, and well deviation data from three wells (KC1, KC2, and KC3) to characterize the stratigraphic trapping configuration, sequence stratigraphy, and seismic facies of the Ekwai Field in the eastern Niger Delta. The adopted workflow involved well-to-seismic correlation, structural interpretation, sequence stratigraphic analysis, seismic facies classification, and depositional environment interpretation. The results revealed stratigraphic traps associated with lateral facies changes, depositional pinch-outs, and five distinct channel-fill architectures (Types I–V). Among these, Channel Types II, III, and IV exhibit favourable seismic attributes, coarse-grained depositional characteristics, and high hydrocarbon prospectivity, whereas Types I and V are understood to be shale-dominated and less prospective. Sequence stratigraphic analysis established five sequence boundaries (SB1–SB5) and four maximum flooding surfaces (MFS1–MFS4), which were correlated across Wells KC1, KC2, and KC3 to define the depositional sequences and associated systems tracts. Seismic facies analysis identified distinct facies assemblages based on reflection configuration, continuity, amplitude, and frequency, enabling the interpretation of lithological variations, depositional energy, and sedimentary environments throughout the field. The integrated interpretation demonstrates that hydrocarbon accumulation within the Ekwai Field is controlled by the interaction of depositional architecture, sequence stratigraphy, and stratigraphic trapping mechanisms. The developed geological model enhances reservoir characterization, reduces exploration uncertainty, and provides a robust framework for hydrocarbon prospect evaluation and future field development within the eastern Niger Delta. The 3-D seismic data conducted in the Ekwai field of the eastern Niger Delta focused on understanding the stratigraphic framework. The main objectives were to identify trapping configurations of stratigraphic traps, and pinpoint channels with potential for hydrocarbon accumulation and analyse facies. The research utilized wireline logs, checkshot, and well deviation data from three wells. The methods included stratigraphic, seismic sequence and seismic facies analyses. Stratigraphic analysis uncovered traps resulting from facies changes, stratigraphic pinch-outs, and five channel fills categorized as types I, II, III, IV, and V. among these, channel types II, III, and IV exhibited promising hydrocarbon potential. In Sequence stratigraphy, four stratigraphic sequence boundaries (SBI, SB2, SB3, SB4 and SB5) and four intrasequence Maximum Flooding Surfaces (MFS1, MFS2, MFS3, and MFS4) were identified.  SB1 and SB2 were correlated across KC1, KC2 and KC3 Wells.  Facies analysis help to distinctively differentiate various facies units and internal reflective configurations, revealing the deposition environment.