Fault growth, displacement scaling and segment interaction in a gravity-driven Niger Delta fault network: Insights from 3D seismic data

Abstract Growth-fault systems in deltaic basins evolve through propagation, interaction and possible linkage, but these processes are difficult to distinguish from geometry alone. This study integrates 3D seismic interpretation and wireline-log correlation to investigate fault growth and segment interaction in the TOYO Field, Niger Delta. Sixty-four faults were mapped across four Agbada Formation horizons (A, B, F and I); 18 faults were selected for quantitative analysis. Analyses included along-strike throw-distance (T-X) and throw-depth (T-Z) profiles, displacement-length (D-L) scaling, relay geometry, and structural maps. Fault lengths range from 0.42 to 19.0 km, defining E-W, NE-SW and NW-SE groups. Kruskal-Wallis tests found no differences among these groups in fault length ( p = 0.0554) or maximum throw ( p = 0.7251). T-X profiles range from symmetrical and flat-topped to asymmetric, double-peaked and irregular. Faults with complex profiles were longer than those with simple profiles (median 4.27 versus 1.77 km; Mann-Whitney U = 6.0, p = 0.0019), whereas maximum throw did not differ ( p = 0.2463). This association may partly reflect greater measurement density on longer faults. Four candidate relay relationships and four candidate interaction/linkage relationships were identified; relay overlap/separation ratios range from 2.48 to 9.65. The geometries and displacement patterns are consistent with segment interaction, displacement redistribution, relay development and possible linkage, but do not establish an evolutionary sequence or prove hard linkage. The analysis provides a framework for evaluating reservoir compartment geometry, although fault sealing and hydraulic connectivity cannot be inferred from geometry alone..