Reservoir Modeling: The Challenge of Data Integration

Dr. Sanjay Srinivasan
Assistant Professor of Petroleum and Geosystems Engineering
The University of Texas at Austin
Adjunct Professor of Chemical and Petroleum Engineering
The University of Calgary

Effective representation of reservoir heterogeneities and the subsequent modeling of fluid flow remain the greatest challenge in reservoir engineering. A good reservoir model is one that integrates the relevant aspects of geological, geophysical and production data. Any single type of data is not enough to constrain reservoir uncertainty to a level conducive to reasonably accurate prediction. Uncertainty is a hard fact better dealt with upfront, focusing on the most consequential model decisions, e.g. geological scenarios or flow types, rather than wingflaps of multiple geostatistical realizations.

This seminar reviews current reservoir and flow modeling approaches and presents some new perspectives. It is argued that improved prediction of future reservoir performance requires a thorough understanding of the influence of geological heterogeneity on flow mechanisms and that understanding has to guide the reservoir characterization and modeling processes. The modeling of an estuarine shoreface-type depositional environment is presented. Various approaches to upscale the high-resolution geologic model were tried, best performance prediction was obtained with a non-uniform coarsened grid. The non-uniform upscaling procedure required a novel algorithm for assigning block effective properties.

The presentation concludes with some perspectives on production history matching of complex reservoir systems. A methodology based on iterative local deformations of reservoir models is suggested. The novel aspect consists of ensuring that any deformation is consistent with the prior geological model.

Dr. Sanjay Srinivasan is an assistant professor of petroleum and geosystems engineering at the University of Texas at Austin and an adjunct professor of Chemical and Petroleum Engineering at the University of Calgary. Dr. Srinivasan's research focus is on reservoir characterization using geostatistics, improved flow modeling in heterogeneous reservoirs, uncertainty assessment and improved decision-making in the presence of uncertainty. Dr. Srinivasan holds a B.Tech. degree in Petroleum Engineering from the Indian School of