A Workflow for Modeling Multi-scale Flow Barriers in Deep Water Turbidite Reservoirs

Li, Hongmei¹, Jef Caers¹ (1) Stanford University, Stanford, CA

In deep water turbidite reservoirs, shale drapes may be distributed along the bases of channel belts and channel bodies. These thin (in to ft) shale drapes are flow barriers that compartmentalize the reservoirs, thus exert strong control on individual well production rates and ultimate recoveries. The geometry and distribution of shale drapes are governed by the eroded surfaces of channel belts and the individual channel body boundaries within such belts. Hence reservoir connectivity is governed by the multi-scale hierarchical nature of these shale barriers. An accurate modeling of these multi-scale flow barriers is critical to reservoir performance prediction.

To model multi-scale flow barriers, we propose a coupled geological modeling and history matching approach to constrain in a 3D reservoir flow simulation model the shale drape presence at all scales. Within this hierarchic workflow, large-scale bounding stratigraphic surfaces (channel belts) and their associated shale drapes are modeled first, next the individual channels within channel belts and their associated shale drapes are simulated, then lithofacies are modeled within each channel, finally continuous petrophysical properties such as porosity and permeability are assigned on a by-facies basis. The workflow allows for the integration of seismic, well-log, formation testing data and historical production and pressure data. A realistic 3D example is presented to demonstrate the proposed workflow.