3D Geological Modeling and Performance Simulation of a Leveed-Channel Outcrop with Application to Deepwater Leveed-Channel Reservoirs
An outcrop of the Cretaceous Dad Sandstone member of the Lewis Shale---termed Rattlesnake Ridge---is an analog to deepwater leveed-channel deposits. It consists of four stacked channel-fill sandstones which are flanked by thin-bedded levees. A 3D geologic-petrophysical model was construct ed using PetrelTM. Input data included: (a) numerous measured stratigraphic sections, (b) a 3D ground penetrating radar survey and (c) petrophysical and reservoir data from a nearby cored and logged research well through similar strata, as well as from Tahoe Field in the Gulf of Mexico. Flow simulation using EclipseTM was completed specifically to evaluate the effect of muddy channel-drape slumps on production and compartmentalization between channel sandstones and adjacent thin beds.
Five depletion simulations and fifteen waterflood simulations were generated, each with different permeability of the slumps and injector well locations. Results showed that low-permeability (<1md) slumps prevented water coning from below, while higher-permeability (up to 40md) slumps allowed coning.
Channel-drape
slumps are common in leveed-channel reservoirs and can cause
compartmentalization, yet they are likely to be deleted during the upscaling
process for reservoir simulation. Our simulations over a 10 year period
resulted in a 44% higher oil production and an additional 4 year field life
between the low permeability and high permeability slumps. We conclude that
deleting such small-scale features in an upscaled model can lead to erroneous
simulation of reservoir performance.
AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California