New Mexico Geological Society Annual Spring Meeting — Abstracts

The Bravo Dome carbon-dioxide gas field is located in union and Harding Counties of northeast New Mexico. The Bravo Dome field covers approximately 800,000 acres, but areal boundaries of the field have not been fully defined by drilling. Production in 1986 was 127 billion ft³ gas from 271 wells. Cumulative production at the end of 1986 was 244 billion ft³. Estimated recoverable reserves are 10 trillion ft³ gas. The gas is 98-99% CO₂. Most CO₂ produced from the Bravo Dome field is used for Enhanced oil recovery in the Permian Basin.

The Bravo dome is a faulted; southeast-plunging, basement-cored anticlinal nose. It is bordered on the east and south by large high-angle faults of Pennsylvanian and Wolfcampian (Early Permian) age.

The principle reservoir in the Bravo dome field is the Tubb sandstone (Leonardian-Permian) at depths of 1,900 to 2,950 ft. The Tubb consists of 0-400 ft of fine -to medium-grained, well-sorted, orange feldspathicsandstone. It rests unconformably on Precambrian basement on the highest parts of the Bravo dome and is not offset by late Paleozoic faul ts that form the dome. The Cimarron Anhydrite (Leonardian-Permian) conformably overlies the Tubb and is a vertical seal.

The trap at Bravo dome has structural and stratigraphic aspects. Drape of Tubb sandstone over the dome created structural closure on the northeast, southeast, and southwest flanks of the field. Trapping on the northwest flank of the field is associated with regional northwest thinning of the Tubb.