Three-dimensional-seismic coherency signature of Niger Delta growth faults: integrating sedimentology and tectonics

摘要

This case study of growth faults and associated deltaic sedimentation in the shallow-offshore Niger Delta uses an integrated analysis of three-dimensional (3D)-seismic coherence facies and wireline data that supports an evaluation of the sedimentary response to delta tectonics. The study area comprises four fault blocks bounded by a set of kilometre-scale, basinward-dipping, synsedimentary normal faults. Correlation of highly variable growth stratigraphy across faults was achieved by a systematic visualization and interpretation of series of coherence horizon-slices: the detection and matching of erosive and depositional patterns (e.g. channels) across faults allowed the establishment of sedimentology-controlled links between diverse footwall and hanging-wall growth successions. At the same time, this interpretation approach helped to visualize seismic-sedimentological and seismic-geomorphological features survey-wide at all depth levels. The integration of this extensive 3D database with lithology information from wireline logs provides a powerful tool for subsurface sedimentology interpretation.