"Inert Gases in the Rocky Mountains: Implications for Risk, Opportunity, and New Understanding in Natural Gas Reservoirs” Bryan McDowell, Colorado School of Mines
Bryan McDowell is a graduate student at Colorado School of Mines currently pursuing a Master’s degree in Petroleum Engineering as well as a Ph.D. in Geology. His research focuses on high-field nuclear magnetic resonance in the Eagle Ford Shale and basin- to reservoir-scale fluvial stratigraphy in western Colorado. He is currently the SPE President for the Colorado School of Mines Student Chapter and the incoming President for the AAPG Student Chapter. He received his Bachelor’s degree in Engineering Geology from Texas A&M University in 2010 and plans to graduate from Mines in Summer 2018.
The Helium System: A Modification of the Petroleum System for Inert Gases
Bryan McDowell, Donna Anderson, Alexei Milkov
Helium is a naturally occurring inert gas commonly associated with oil and gas accumulations. Although it generally constitutes less than two percent of the total gas stream, its occurrence within specific stratigraphic intervals and geographic areas can shed light on gas migration pathways within a basin. Moreover, the recent rise in helium prices and contemporaneous drop in oil and gas commodities has piqued commercial interests where oil and gas infrastructure, insight, and expertise is readily available. Most petroleum explorationists are not familiar with helium exploration; however, a widespread and common method may be easily modified for our purposes: the petroleum system. The petroleum system concept has been used successfully for decades to high-grade plays and de-risk oil and gas prospects around the world. We propose a modification of the petroleum system approach to aid exploration for helium resources and other inert gases.
Like a petroleum system, the helium system is identified by its source rock, reservoir, trap, seal, and migration pathway. Two helium systems are identified and tentatively called the Uncompahgre and Uinta systems; named after their interpreted source rock intervals. The helium gas, as well as nitrogen and carbon dioxide, are believed to migrate through basinal brine systems until trapped in conventional petroleum traps. These gases are found primarily in formations directly below the Mancos Shale which provides a basin-wide seal for both helium systems and prevents significant leakage to the younger Mesa Verde, Wasatch, and Green River gas-productive intervals. A case study was undertaken in the Uinta Basin of eastern Utah and Piceance Basin of northwestern Colorado to provide a proof-of-concept. These basins produce nearly three percent of the total natural gas in the United States and contribute appreciable amounts of helium from various geologic formations. We also used a common risk segment (CRS) approach to map areas of low, moderate, or high risk for the occurrence of pools with significant helium content.