More and more, oil and gas companies are faced with extracting precious minerals from unconventional reservoirs that are difficult and costly to access. They have an ally in Mohammad Piri, a University of Wyoming School of Energy Resources associate professor of chemical and petroleum engineering, who heads the Hess Digital Rock Physics Laboratory in UW’s new Energy Innovation Center (EIC).

“This lab provides UW scientists with huge scientific advantages in performing multi-scale, multi-phase fluid flow in porous media research with applications in oil and gas recovery from unconventional and conventional reservoirs where extremely complicated flow and transport physics are encountered,” Piri says. “The establishment of improved understanding of flow and transport in these systems will lead to the development of new hydrocarbon recovery techniques.”

Wyoming is the No. 3 producer of natural gas and No. 8 producer of crude oil nationally, according to the U.S. Geological Survey. However, enhanced recovery techniques are needed to retrieve a high percentage of hydrocarbons that are stranded in the state’s mature or older fields, Piri says. For example, about 50 percent to 70 percent of the original oil in place remains stranded in Wyoming’s aging fields, and enhanced oil recovery methods are needed to retrieve 5 percent to 15 percent of that oil and extend the commercial life of those fields 20-30 years.   

This lab, part of the EIC's Reservoir Characterization Suite, is the “world’s most innovative for advanced reservoir characterization,” says School of Energy Resources Director Mark Northam.

“It’s a combination of the facilities being state of the art with research instruments that don’t exist anywhere else for this application,” Northam says. “To have the full range of (equipment) for this application is unique. Clearly, (Piri) is one of the world’s leaders in combining the experimental and computational aspects of advanced reservoir characterization. His record speaks for itself.”

“To the best of my knowledge, there is no petroleum engineering research group in academia, in the world, that has integrated these three laboratories, and is covering such a wide range of scale ( i.e., macro, micro and nano) in their research,” Piri says.

Lab Logistics

The Hess Digital Rock Physics Laboratory includes the most advanced high-resolution 3-D X-ray microscope available, making UW the world's first university to put this state-of-the-art tool in the hands of faculty and researchers to increase understanding of underground oil and natural gas reservoirs. The X-ray machine produces ultra-high-resolution images of reservoir rock on the nano-scale. Piri compares it to seeing more topographic details on a Google Earth map. For example, if the nano-scale were applied to a Google Earth map, Piri says the details in a small alley would represent the nano scale, while the outline of a large highway would represent the micro-scale level.

“We can recreate underground flow, temperature and pressure conditions -- real things that are encountered underground in real reservoirs,” Piri says of what can be accomplished with core samples using the advanced equipment.

Piri’s existing Phase II 3-D X-ray machine (which can produce reservoir rock images on the micro-scale level) also is housed in the laboratory.

The first phase of Piri’s research lab facility, which opened in 2008, will remain in the Encana Research Laboratory, which is located in the UW Engineering Building. Equipment there includes a medical CT scanner, much like the type used in hospitals. It can view core samples at the macro- level, Piri says.

The new 3-D Visualization Lab, which includes a 3-D CAVE™ (Cave Automatic Virtual Environment), will complement his lab’s work. Researchers will be able to use core sample data they’ve modeled and view it in multiple dimensions to better understand how multi-phase fluids flow in conventional and unconventional reservoirs.

In addition, Piri says a hybrid Graphics Processing Unit (GPU)-Computer Processing Unit (CPU) computer cluster he built -- which will serve as a satellite cluster for UW’s Mount Moran computing cluster -- is currently being used for computational modeling of porous media and reservoirs.

Rock Solid

Unconventional reservoirs are composed of a rock matrix that consists of pore networks with very small pore connections that share very poor fluid-flow characteristics. Oil or gas, in abundant amounts, can be stored in these rock types, which include shale and tight sandstone. Often, the rock is high in organic content and is the source of the hydrocarbon. But, because of marginal rock matrix quality, these reservoirs generally require both natural and induced fracturing to enable economic recovery of the hydrocarbon.

Some unconventional reservoirs aren’t suitable for fracturing because the rock deforms and fractures close up soon after they are created, Northam says. The Green River shale in southwestern Wyoming and down into Colorado is a prime example of an unconventional reservoir that cannot easily be fractured and where very little production has occurred to date.

“There’s probably 1 trillion barrels of oil in place there,” Northam says. “We currently don’t have the technology to produce economically from the Green River shale. (Solving that dilemma) is potentially one of the things we hope to accomplish with this lab.”

In an Aug. 16, 2012 column, Peter Glover, European associate editor for the U.S. magazine Energy Tribune, notes that, at current levels of American oil consumption -- 19.5 million barrels a day -- Green River, alone, could supply domestic U.S. oil needs for the next 200 years.

Tapping such an oil supply would make the U.S. less reliant, and perhaps completely independent of, the Middle East for a percentage of its oil supply.

Beyond Unconventional

Piri stresses the new lab will benefit academia and industry beyond the study of physics of fluid flows in unconventional reservoir rock. The lab also can be used to study, for instance, fluid flows in conventional reservoirs; porous material research, including modeling of displacement processes; carbon dioxide sequestration (capturing carbon dioxide and storing it long-term in geologic formations deep underground); catalysis (the chemical reactions enhanced by a catalyst); and polymers, which are chemical compounds that can be used for a wide range of applications.

In addition, Piri says the lab will be used to instruct senior-level undergraduate students and graduate students in two of his courses: Flow Through Porous Media and Fundamentals of Enhanced Oil Recovery.

Experience in this lab will give UW students a better insight on where and how to obtain the reservoir properties they need to assess the success of a given recovery process, Piri says. Such insight can be translated into relaying on-the-job knowledge when talking about the subject with petrophysicists, geologists, geochemists and geophysicists.

“When they (students) understand these properties and their behavior under various reservoir flow conditions, they can talk to these professionals. They will be well prepared to contribute to the discussion,” Piri says. “Properties measured in the lab are absolutely essential for accurate assessment of the performance of various oil and gas recovery techniques for conventional and unconventional reservoirs.”

Assisting the Industry

Hess Corporation, which donated $4.4 million for construction of the lab, has shale assets in North Dakota, France and China. The company hopes to benefit from the lab’s research, says Piri, who also is director for UW’s Center for Fundamentals of Subsurface Flow.

In addition, the U.S. Department of Energy; Total, a French energy company; Saudi Aramco, the national oil company of Saudi Arabia; and Encana Corp. are other entities that will use these labs or benefit from research conducted there, Piri says. And there’s a possibility for even more entities to use and/or collaborate in the lab.

“We’ve had numerous scientists and engineers from universities, companies and research institutions visit and discuss collaborative research initiatives,” Piri says. “Absolutely, we believe this will be a game changer for multidisciplinary flow in porous media research on campus, with implications for the state of Wyoming, the country and the world.”

The implications are to recover as much of the stranded oil as possible, he says.

“That cannot happen without developing a deeper insight on how those flow processes are taking place on a pore-by-pore basis,” Piri says. “If that type of insight becomes available, one can engineer a (recovery) technique that is successful.”

The Reservoir Characterization Suite includes the Marathon Oil Research Offices and the ConocoPhillips Collaboration Room. The research offices are equipped with office space for visiting professionals and researchers from other universities and industry. The collaboration room offers a space designed to bring researchers, industry, faculty and other professionals together to coordinate and discuss the various research projects being conducted within the Reservoir Characterization Suite.

Photo:
University of Wyoming research scientists Henry Plancher (center) and Soheil Saraji (right), and graduate student Vahideh Mirchi (left), measure interfacial tension and contact angles in the Hess Digital Rock Physics Laboratory, part of UW’s new Energy Innovation Center. (UW Photo)