Abstract There has been debate over the processes acting on deep-water channels, with comparisons made to the evolution of meandering fluvial systems. We characterized a three-dimensional seismic-reflection dataset of the Joshua deep-water channel–levee system located in the eastern Gulf of Mexico and interpreted 13 horizons showing its kinematic evolution over a 25 km reach. Over this reach, we documented channel migration through systematic bend expansion and downstream translation, which was sustained through channel aggradation as sinuosity increased from 1.25 to 2.3 at abandonment. An abrupt decrease in sinuosity was associated with a neck cutoff, which changed the subsequent migration direction of the channel in that locality. These processes are analogous to the evolution of meandering fluvial systems. We show that increasing channel sinuosity correlates to a reduction in channel slope and hypothesize that this promoted increasingly depositional turbidity currents that led to channel aggradation. Using a simple forward stratigraphic model in which vertical movements of the channel are governed by a stream power law, we show how aggradation can be driven autogenically. Trends in sinuosity, aggradation and slope are in broad agreement between the Joshua Channel and the model. This highlights the potential importance of intrinsic channel processes as a control on system evolution.

Abstract Three-dimensional circumferential CT-scans have transformed how core is described and calibrated with borehole image (BHI) datasets to refine reservoir rock typing and facies description. This paper focuses on the value of circumferential CT-scans in the assessment of plug and bed-scale heterogeneities. It shows how careful re-orientation and calibration with borehole images can help unravel sandbody geometries and orientation, and the potential effects of cross-cutting deformation bands on permeability architecture and sweep efficiency. This is demonstrated using aeolian-dominated core examples, supported with circumferential CT-scans, minipermeability data, conventional logs and BHI data, taken from the Jurassic Norphlet Formation from producing fields in the Gulf of Mexico. The formation overlies Early Jurassic Louann Salt, and syn-depositional halokinesis significantly influenced depositional accommodation space, facies distribution, and preservation potential. Furthermore, deposition during active salt tectonics has resulted in complex deformation band networks within these clean sandstones. CT-scan density contrasts highlight stratification types and deformation bands not always visible on slabbed core. Furthermore, BHI re-orientated CT-scans provide high-resolution dip/azimuth data and aid aeolian bedset bounding surface definition, which is important for determining dune geometry and stacking patterns. Hence, an integrated approach using core, circumferential CT-scan and calibrated BHI has been essential for deciphering the complexity of these deposits.