The Barrett Resources Cave Gulch Federal Unit #1 discovered one the most significant new natural gas fields in the last decade in the Rocky Mountain region. The Cave Gulch Field is located below the Owl Creek Thrust in the Wind River Basin, Natrona County, Wyoming. The discovery well encountered gas in the Tertiary Fort Union and Cretaceous Lance Formations down to a depth of 6,905'. Since an initial rate of 9.7 MMCFD and 117 BCPD, the well has produced 9 BCF. Development wells have continued to find gas to 10,000' in the Lance Formation. Net pay ranges from 250-1000' in lenticular fluvial sands. Initial rates range from 2-20 MMCFD per well. Total field production from the Cave Gulch Field area is over 150 MMCFED.

In 1995 the productive pay zones were extended to a depth of 10,650' in the Mesaverde Formation. Field pay was deepened by drilling the 19,106' Cave Gulch #16 to the Frontier, Muddy and Lakota Formations. The Third Frontier at 17,386' was completed at a rate of 10.2 MMCFD. Reserve estimates for Cave Gulch Field area from the Ft. Union and Lance Formations may exceed 400 BCF with the Frontier, Muddy and Lakota adding considerably more reserves as development proceeds. In September 1997 Barrett spud a 21,150' well to the Mississippian Madison Formation to explore for deeper gas in Cave Gulch Field.

AAPG Search and Discovery Article #90937©1998 AAPG Annual Convention and Exhibition, Salt Lake City, Utah