Abstract

More than 171 million barrels of oil and 2.7 trillion cubic feet of gas have been produced from oil and gas fields in the Cordilleran thrust belt and southern Green River basin in Summit County, Utah. However, the county still contains large, promising areas that are virtually unexplored. Potential prospects are within the economic and technical capabilities of both major and independent operators. These potential prospects are structurally and stratigraphically analogous to producing fields in the county and elsewhere in the Rocky Mountain region.

Summit County has at least 10 major petroleum plays that contain drilling targets grouped by common geologic parameters such as structural setting, depositional environment, or petroleum trapping mechanism. These plays represent the maximum extent of petroleum potential in a geographical area as defined by producing reservoirs, hydrocarbon shows, and untested hypotheses. Most plays have multiple potential reservoirs that range in age from Cretaceous to Ordovician. Several plays overlap to create areas with numerous vertically stacked traps and reservoirs. However, exploratory-well density in these play areas is relatively sparse, averaging 10.5 square miles per well, leaving large parts of the county unexplored.

The attractiveness of the petroleum plays in Summit County to the petroleum industry varies depends on the likelihood of successful development, reserve potential, pipeline access, drilling costs, oil prices, and environmental concerns associated with the individual plays. When evaluating these criteria, certain plays meet the exploration guidelines for major companies while other plays meet the guidelines of small, independent companies. The successful use of horizontal-drilling techniques and the completion of a sour-gas pipeline in the county have greatly increased the potential for both exploration and development in several plays.