Dual-Porosity/Dual-Permeability Modeling of a Fractured Carbonate Reservoir

Meurer, M. Ellen¹, Ping Li¹, Lester Landis¹, Michele Thomas¹, Susan Stark² (1) ExxonMobil Upstream Research Company, Houston, TX (2) Imperial Oil Resources, Calgary, AB

As the world’s fractured reservoir assets become increasingly important, new approach­es must be developed in fractured reservoir modeling and simulation to maximize produc­tivity, improve economic forecasts, and inform business judgements. To address this need, we developed and validated a fractured reservoir modeling and simulation workflow, that integrates fracture characterization, geologic modeling, and fractured reservoir simulation technologies. The workflow includes 1) using a common-scale framework for geologic and simulation models, 2) simulating fine-scale element models to compute effective matrix per­meabilities, 3) analyzing fracture data obtained from core, FMI logs, and outcrop, and 4) integrating analysis of field performance, structure, stratigraphic facies, and regional geolo­gy. Directional equivalent fracture permeabilities, porosity, and matrix block dimensions were estimated using a 3D geologic model-based discrete fracture network (DFN) model. Dual-porosity/dual-permeability reservoir simulation models were built using similar grid geometry and discretization scale, the new effective matrix properties, and the DFN-gener-ated fracture properties. Simulation results were compared with a long history of multiphase production, with the new model showing a better history match than the previous single­medium model. We conclude that for our test case, a dual-porosity/dual-permeability model more accurately captures the impact of fractures on fluid flow than does a single-medium model; and our study demonstrates an effective and efficient dual-porosity/dual-permeabil-ity fractured reservoir modeling and simulation strategy.