Computer Modeling of Internal Architecture in Deep Water Reservoirs: A Quantitative Method to Estimate Connectivity and Performance

Renjun Wen¹ and Mark Barton^2
1 Geomodeling Technology Corp, Calgary, AB
² Shell International Exploration and Production, Houston, TX

We present a computer modeling method to reproduce the 3D internal architecture of deep water reservoirs, in order to evaluate connectivity and production performance for different geological scenarios. The workflow consists of three steps. The first step is to simulate a stratigraphic grid using a 'process-oriented' heterogeneity modeling method. The method mimics the sedimentary processes that form the internal architecture of deep water reservoirs. These processes include deposition, erosion and migration of depositional centers. The resulting models simulate layer geometry and facies distributions of deep water reservoir architectures, such as boundary layers, channel infill, levees and lobes. All modeling parameters can be either deterministically specified or sampled from probability distributions.

The second step is to simulate reservoir properties, such as porosity and permeability, using geostatistical methods. The spatial distribution of reservoir properties is conditioned by stratigraphic trends and facies. Both stratigraphic and reservoir property grids can be exported as corner point grids, which can be handled by any reservoir simulator. In the third step, a streamline-based reservoir simulator is used to model production profiles of geological models generated in the first two steps. Based on multiple geological simulations, we can derive probability distributions of recovery factor under different geological scenarios. The above workflow is demonstrated with examples to estimate dynamic connectivity and reservoir production performance of deep water reservoirs.