Current compositional simulators include compositional equation-of-state fluid models, but do not account for compositional effects on relative permeability, capillary pressure, and grid-block flux calculations. Relative permeability, for example, is still based on “old thinking” related to labeling of phases as “oil, gas, and water.” Labeling causes significant discontinuities that can result in inaccuracies and instability in simulations of compositional processes, such as those for enhanced oil recovery (EOR).
This presentation will show you why labeling is “old thinking” and how labeling generates discontinuities and simulation errors in compositional processes. Several example cases, including water-alternating-gas and surfactant flooding, are given using a new type of compositional simulator with all labels removed. One component of the novel simulator is the development of an equation of state (EoS) for relative permeabilities that eliminates phase labeling. The relative permeability model is physically based and captures complex hysteresis effects through saturation and phase connectivity as well as changing wettability, interfacial tension, and pore morphology. Results show increased robustness, improved accuracy, faster computational times, and less instabilities when phase labeling is removed.
Russell T. Johns is the George E. Trimble Chair of Energy and Mineral Sciences at the Department of Energy and Mineral Engineering at The Pennsylvania State University. He also holds the Energi Simulation Chair in Fluid Behavior and Rock Interactions. He recently served as Chair of the Petroleum and Natural Gas Engineering Program, and is currently the Editor-In-Chief for SPE journals.
Prior to his current position at Penn State, he served on the petroleum engineering faculty at The University of Texas at Austin for fifteen years. He also has nine years of industrial experience as a petrophysical engineer with Shell Oil and as a consulting engineer for Colenco Power Consulting in Baden, Switzerland. He holds a BS degree in electrical engineering from Northwestern University and MS and PhD degrees in petroleum engineering from Stanford University. He has over 250 publications in enhanced oil recovery, thermodynamics and phase behavior, unconventional gas engineering, multiphase flow in porous media, and well testing. Dr. Johns received the SPE Ferguson medal in 1993, the SPE Distinguished Member award in 2009, the SPE Faculty Pipeline award in 2013, the 2016 SPE international award in Reservoir Description and Dynamics, and the 2018 Wilson Excellence in Research award from the College of Earth and Mineral Sciences. He is currently director of the Enhanced Oil Recovery consortium in the EMS Energy Institute at Penn State University.