Abstract

Carbon dioxide (CO₂) occurs as a common component of natural gases throughout New Mexico. In most gases, CO₂ is a minor constituent and comprises less than 1 percent of the gas. More rarely, CO₂ is the dominant component of the gases and may constitute more than 99 percent of the gas. Some accumulations of this nearly pure CO₂ have been produced commercially for their CO₂ content.

Most gases in the Permian Basin of southeastern New Mexico contain less than 1 percent CO₂. In general, stratigraphic units comprised predominantly of carbonate rocks harbor gases that contain higher percentages of CO₂ than units comprised predominantly of siliciclastic sedimentary rocks.

In the San Juan Basin of northwestern New Mexico, most gases in Cretaceous reservoirs contain less than 1 percent CO₂. Cretaceous gases contain more than 1 percent CO₂ in the deep northern part of the basin. Gases in Pennsylvanian reservoirs contain more than 10 percent CO₂ along trends on the Four Corners platform and in the deeper parts of the San Juan Basin. Gases in Mississippian reservoirs are comprised of more than 90 percent CO₂ over large areas.

Widespread accumulations of gases that are nearly pure CO₂ are present over large parts of the Bravo Dome and Sierra Grande uplift of northeastern New Mexico. CO₂ has been produced commercially from the Bravo Dome field that has yielded a cumulative production of more than 1.2 trillion ft³ CO₂ gas. Triassic sandstones are secondary reservoirs at Bravo Dome. CO₂ has also been produced from the much smaller, now-abandoned Des Moines field on the Sierra Grande uplift. Significant potential remains for undiscovered CO₂ resources on the Sierra Grande uplift and Bravo Dome.

In north-central New Mexico, CO₂-rich gases are present within Pennsylvanian and Lower Permian sandstones in the vicinity of large igneous intrusions in the Las Vegas Basin. In the Raton Basin, gases composed primarily of CO₂ occur in Triassic sandstones and in the Glorieta Sandstone (Permian).

In central New Mexico, CO₂-rich gases are present in the Estancia Basin, in the Chupadera Mesa area, and in the Albuquerque Basin. CO₂ has been produced from two small, now-abandoned accumulations in Lower Pennsylvanian sandstones in the Estancia Basin. Potential for additional CO₂ resources is limited. On Chupadera Mesa, recent exploratory drilling has revealed the presence of CO₂ in Lower Permian sandstones. CO₂ has been encountered in Tertiary-age sandstone aquifers in the Albuquerque Basin.

CO₂ has been encountered by exploratory wells drilled in west-central New Mexico. The St. Johns CO₂ field of Arizona extends into westernmost Catron County. Sparse exploratory drilling elsewhere has revealed the presence of CO₂-rich gases in Pennsylvanian and Permian reservoirs in eastern Catron and Cibola Counties.