The impact of fine-scale reservoir geometries on streamline flow patterns in submarine lobe deposits using outcrop analogues from the Karoo Basin

M. Hofstra, A. S. M. Pontén, J. Peakall, S. S. Flint, K. N. Nair, D. M. Hodgson
2016 Petroleum Geoscience  
Improved prediction of the recovery of oil-in-place in basin-floor fan reservoirs requires 12 accurate characterisation and modelling of multiscale heterogeneities. The use of outcrop analogues 13 is a key tool to augment this process by documenting and quantifying sedimentary architecture, 14 hierarchy, and sedimentary facies relationships. A 3D geological modelling workflow is presented 15 that tests the impact of fine-scale heterogeneities within basin-floor lobe complexes on reservoir 16
more » ... nectivity. Construction of geological models of a basin-floor lobe complex allows realistic 17 depositional architecture and facies distributions to be captured. Additionally, detailed models are 18 constructed from channelised areas within a basin-floor lobe complex. Petrophysical modelling and 19 streamline analysis are employed to test the impact on reservoir connectivity between lobe models 20 with i) vertically-stacked facies with coarsening-and thickening-upwards trends in all locations, and 21 ii) lateral facies changes with dimensions and distributions constrained from outcrop data. The 22 findings show that differences in facies architecture, and in particular lobe-on-lobe amalgamation, 23 have a significant impact on connectivity and macroscopic sweep efficiency, which influence the 24 production results. Channelised lobe areas are less predictable reservoir targets due to uncertainties 25 associated with channel-fill heterogeneities. The use of deterministic sedimentary architecture 26 concepts and facies relationships have proven vital in the accurate modelling of reservoir 27 heterogeneities. 28 29
doi:10.1144/petgeo2016-087 fatcat:4oetbxwgvrc4di6tnnfaicsogi