Events

Dr. Maria A. Barrufet, Professor and Baker Hughes Endowed Chair at the Harold Vance Department of Petroleum Engineering at Texas A&M University will be presenting on "Depletion of 'Gas Assisted' Improved Oil Recovery in Liquid-Rich Shale - from Understanding to Practice".

Abstract:

Recent developments in technology transformed unconventional low-permeability shales as reliable energy sources. Capacity wise, unconventional resources are found to be more abundant than conventional ones. However, low hydrocarbon recovery from liquid-rich shale plays remains challenging to the petroleum industry. While not completely resolved, the problem becomes less severe when gases (with a lower viscosity) are used. There have been a number of efforts to investigate various gas injection/cycling scenarios to improve recovery of shale.  However, the problem still remains as conventional approaches cannot be used to describe, and predict, the complex behavior of fluids in pore sizes 4 to 5 orders of magnitude smaller than conventional sandstone pores.  As expected, thermodynamic and transport properties of reservoir fluids in confinement can significantly impact flow behavior and recoveries, whether the production is under depletion or using some assisted recovery scheme.  

With this presentation I expect to provide you a brief overview of the current approaches to describe confinement, with advantages, limitations, uncertainties, and the reasoning that led us (my group) to choose a particular approach.

Mass transfer, weather induced (i.e. gas assisted) or from depletion in liquid-rich shales requires a solid understanding of the thermodynamic and transport behavior of fluids in confined media. Based or published pore size distributions for shale formations, up to 40 to 50% of the hydrocarbon pore volume may be contained in pores smaller than 40 nm.   The same reservoir models used for conventional reservoirs cannot explain the fundamental mechanisms taking place when producing unconventional resources. History matching can always be achieved, often at the expense of using wrong or heavily correlated parameters, leading to non-unique and/or unreliable forecasting. Our goal is to use physics based models that can be readily applied and integrated into the mathematical mainframe of commercial simulators.

We have incorporated confinement in our thermodynamic model and validated observed phenomena of bubble point pressure depression, and higher gas-oil-ratios for condensate systems.  In this presentation I will walk you through our research stages, modeling simplifications, experimental results, disappointments, mechanistic approaches, accomplishments, and where we stand now. The exciting part is that the more we know we are more certain that the understanding phase will never end.

About Dr. Barrufet:

Dr. Maria A. Barrufet is a professor of petroleum engineering, director of Online Learning, and Baker Hughes Endowed Chair at the Harold Vance Department of Petroleum Engineering at Texas A&M University. 

She holds BS and MS degrees from Universidad Nacional de Salta Argentina and a Ph.D. from Texas A&M University.

Her research interests are multicomponent thermodynamic and transport phenomena in nanoscale pores applied to compositional reservoir simulation, flow assurance, and desalination processes to treat oilfield brines. She is a Distinguished Member of the Society of Petroleum Engineers (SPE). She is a recipient of Texas A&M University’s Charles Crawford Distinguished Service Award (2006, 2012-13), and Regional Distinguished Achievement Award for Petroleum Engineering Faculty SPE (2015).