Events

Dr. Michael J. King, Professor at Texas A&M University, will present a lecture entitled "Diffuse Source Upscaling" as part of the Claude R. Hocott Graduate Seminar Series.

Bio:

Dr. Michael J. King is a Professor and Assistant Department Head in the Department of Petroleum Engineering at Texas A&M University. He is the holder of the LeSuer Chair in Reservoir Management and the Foundation CMG Chair in Robust Reduced Complexity Modeling. He became a Distinguished Member of the Society of Petroleum Engineers in 2013, and is recipient of the 2011 SPE Reservoir Description and Dynamics Award. He has also served as an SPE Distinguished Lecturer and is the co-author of the SPE textbook on Streamline Simulation: Theory and Practice. He joined A&M in 2009, after retiring from BP America as a Senior Advisor in Reservoir Modeling and Simulation. He was with BP for 27 years, both in the U.S. and overseas, in a variety of technology and operational roles. Research interests include reservoir characterization, reservoir management, fundamentals of flow in porous media, upscaling of geologic models for flow simulation, and more recently pressure and rate transient and unconventional reservoir analysis. His original training was in physics and mathematics, with a PhD in theoretical physics from Syracuse University in 1980 and physics and math BS degrees from The Cooper Union in 1976.

Abstract:

Static high resolution three dimensional geological models are routinely constructed to provide an integrated description of a reservoir which includes seismic, well log, and core data, and which characterize the reservoir heterogeneity at multiple scales. These models also represent the structure and stratigraphy of the reservoir within the design of the modeling grid, which may include fault blocks, faults, pinch-outs, layering and cross-bedding. The growth of computational resources has remained rapid, and both geologic models and flow simulation models have increased in size. 50 million cell geologic models are routine, while simulation models are typically one or two orders of magnitude coarser. Hence upscaling of the geologic models for flow simulation remains part of the subsurface workflows.

The industry also faces new reservoir engineering challenges. Unconventional reservoirs (tight gas / shale oil / shale gas) have sufficiently low permeabilities that the time for pressure transients are no longer measured in hours or days, but instead are measured in decades or longer. The separation between transient testing and steady state reservoir management is no longer applicable. Historically, our upscaling algorithms have relied upon steady state concepts of flow, which are no longer applicable.

In the current study, a novel diffuse source upscaling approach is described. It applies pressure transient drainage volume concepts to the calculation of the effective flow between reservoir simulation coarse cell pairs. Unlike the usual steady state upscaling algorithms, it is a completely local calculation and is not dependent upon knowledge of, or assumptions about, global reservoir flow patterns. Its use is not restricted to unconventional reservoirs, however, it is well suited to performance prediction within unconventional reservoirs as the concept of undrained volume fraction can be used to validate the upscaling and pseudo steady state reservoir simulation assumptions. The approach is tested using the conventional reservoir SPE10 waterflood data set. It is then validated at field scale using an onshore US tight gas reservoir model. The approach is shown to reduce simulation run times by up to two orders of magnitude without significant loss of accuracy in performance prediction.