Analysis of Niger Delta Growth Faults in 3-D Coherency Data: Integrating Tectonics and Sedimentology

Back, Stefan¹, Marius B. Brundiers², Christian Höcker³, Peter A. Kukla¹ (1) RWTH Aachen, Aachen, Germany (2) Jean Lutz SA, Jurane, France (3) Shell International E&P, Rijswijk, Netherlands

We describe a 3-D seismic interpretation technique that supports a detailed analysis of the sedimentary and tectonic development of deltaic units affected by growth faults, based on a case study from the shallow-offshore Niger Delta. The study area comprises four fault blocks bounded by a set of kilometre-scale, basinward-dipping, synsedimentary normal faults. Each fault block exhibits a unique stratigraphic signature, making seismic and well­log correlations across the growth faults difficult.

The problem of unambiguous horizon mapping was largely overcome by a systematic bottom-to-top visualization and interpretation of coherence horizon-slice data: mapview detection of matching seismic-sedimentological features (e.g. channels) that extend from one fault block into another enabled the establishment of sedimentology-controlled links between the diverse footwall and hanging-wall growth stratigraphy. The workflow and inter­pretation results presented should be considered when undertaking integrated subsurface sedimentology- and lithology-prediction studies in growth-faulted deltaics, as well as for the analysis and modelling of synsedimentary fault kinematics.