UW Researchers Publish Article Exploring Mowry Shale Geomechanics

University of Wyoming researchers have published a critical review of the relationship among pore architecture, geomechanics and fluid flow during production-induced pressure decline in shales. This examination is a necessary step in identifying the factors that need special attention in researching burgeoning oil and gas reservoirs in Wyoming, such as the Mowry Shale.

The study, led by doctoral student Ifeanyi Nwankwo, examined the complexities of fluid movement through shale and the rock deformation and offered a path forward for research. Nwankwo, originally from Ifitedunu, Nigeria, is in the Department of Energy and Petroleum Engineering in the UW College of Engineering and Physical Sciences.

The article, titled “A critical review of experimental and theoretical studies on shale geomechanical and deformation properties, fluid flow behavior, and coupled flow and geomechanics effects during production,” was published in the International Journal of Coal Geology.

Co-authors include Morteza Dejam, an associate professor in the Department of Energy and Petroleum Engineering, and Scott Quillinan, senior director of research in UW’s School of Energy Resources (SER).

"Understanding the geomechanical complexities of formations like the Mowry Shale is crucial for optimizing resource recovery,” Nwankwo says. “This review highlights key factors influencing production and emphasizes the need for integrated experimental and modeling approaches to enhance efficiency and minimize uncertainties.”

The paper stems from SER's investment in UW-led research to unlock the potential of the Mowry Shale through research, industry collaboration and student training.

An important petroleum source rock in the Rocky Mountains known as a self-contained petroleum system, it’s a primary hydrocarbon source for Cretaceous petroleum reservoirs in the Powder River Basin and also a reservoir in itself. SER aims to diminish uncertainties and enhance the productivity of the Mowry Petroleum System to bolster statewide production.

Proposals from Dejam were successfully selected in both of SER’s funding opportunities for the Mowry Project. Under the second phase, his team focused on the fundamental investigation of fluid phase transition confined in Mowry Shale, leveraging Nwankwo’s growing expertise in how flow and geomechanical properties respond during pressure reduction in shale.

“I am incredibly proud of Ifeanyi’s hard work and perseverance in bringing this comprehensive study to fruition,” Dejam says. “His meticulous work and insightful analysis have contributed significantly to our understanding of shale geomechanics and fluid flow.”

The paper provides a summary of the fluid flow and geomechanical characterization of shale formation. It identifies the factors that influence rock deformation and fluid flow during production and found that flow regimes predominantly depend on pore pressure and size, whereas flow regimes regulate apparent permeability.

Additionally, the review shows that geophysical metrics are more sensitive to pressure changes during depressurization than geomechanical properties. The authors ultimately conclude that recovery from shale could be optimized by integrating experimental studies with hydromechanical models during initial reservoir studies.

“Shales are always tricky, and they have unique behaviors,” says Tim Fischer, program manager of the Mowry Shale Project. “But, as we continue to develop knowledge, it’s vital to look back and see what problems they may have in common. This paper is an excellent example of that and makes the path to better production from the Mowry a little clearer.”

The full article can be downloaded here: https://doi.org/10.1016/j.coal.2025.104777.