This paper investigates the impact of sedimentary heterogeneities on performance of waterflooding in shallow marine reservoirs. Reservoir simulation models are developed from detailed geological models based on a four-level sedimentary architectural hierarchy ranging from sedimentary structures (wave ripples, hummocky cross-stratification) up to parasequences. Single- and two-phase flow properties are upscaled to capture the effects of small scale heterogeneities on performance. The relative influence of 12 heterogeneity factors is determined using experimental design and analysis of variance. The analysis identified large scale features (parasequence thickness and stacking patterns) to be of primary importance for waterflood performance. These features control the relative proportion of fades belts in the reservoir, which correlates with recovery. Other important, though secondary, heterogeneities include interfingering of facies belts, and small scale bedding.

Keywords:
experimental design, transition zone, upstream oil & gas, recovery, heterogeneity, laminae, ripple, parasequence, permeability, lower shoreface
Subjects:
Reservoir Characterization, Reservoir Fluid Dynamics, Improved and Enhanced Recovery, Reservoir Simulation, Formation Evaluation & Management, Exploration, development, structural geology, Geologic modeling, Flow in porous media, Waterflooding
Copyright 1994, Society of Petroleum Engineers
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