Seismic expression of submarine channels and seafloor morphology, deepwater western Niger delta

Abstract

 Submarine channels are the primary targets of deep-sea hydrocarbon exploration and 
production. They are repositories for huge accumulation of reservoir sands. With the 
increased focus on deep-sea hydrocarbon exploration, it is imperative to continue to 
advance research relating to these significant underwater sediment host structures. We 
have, in this study, utilized a high-resolution, 3D seismic reflection dataset covering an 
area of 950 km2 in the deepwater western Niger delta to characterize and understand 
interactions between these subaqueous channels and seafloor. Our study revealed a sea
f
 loor characterized by crescent-shaped, low-angle, gentle dipping-walled submarine chan
nels, fault scars, pockmarks, and a shale-cored anticlinal fold structures. The seismic facies 
associated with the channels includes moderate to high amplitudes and discontinuous to 
continuous seismic reflections. The channels were mainly associated with reservoir sands 
and followed topographic lows, trending downflow, NW–SE of the study area. A major 
low sinuosity (<1.10) channel of about 15.4 km long, with a vertical relief of over 200.0 
m to the channel floor traversed the study area. Although there is no evidence of seabed 
incision and erosion of this major channel, there is a tendency for channel deflection away 
from the seafloor relief due to the growth of anticlines above the toe-of-thrust area which 
could result in an increase in channel width and thus more accommodation space for 
reservoir sands deposition.