Helium in New Mexico:
Geologic Distribution and Exploration Possibilities*
Ronald F. Broadhead1
Search and Discovery Article #10117 (2006)
Posted October 20, 20006
*Presentation at Tulsa Geological Society, October 10, 2006
1New Mexico Bureau of Geology and Mineral Resources, A Division of New Mexico Tech ([email protected])
Helium’s unique physical and chemical properties lend it to many uses for which there is no substitute. In addition to its well-known property of being a low-density (“lighter-than-air”) gas, its boiling point is –269oC, the lowest of any substance; it therefore has invaluable uses as a coolant. It is also inert and nonreactive with other substances in all but the most extreme conditions, so it has application as a nonreactive atmosphere. Its main uses are as a coolant in magnetic resonance imaging (MRI) instruments and an inert atmosphere in semiconductor manufacturing. Its use as a lifting gas is relatively minor.
The U.S. does not import helium but instead exports it, providing 85 percent of the world’s helium production. Helium sales in the U.S. increased from 4 to 4.3 BCF from 1998 to 2004. During this same time period, domestic production of helium decreased from 4 BCF to 3 BCF. The shortfall in production has been filled by withdrawing helium from storage. As demand has exceeded production, prices have risen from $42/MCF in 2000 to $65/MCF in 2004. The trends of increasing demand and decreasing production indicate a need to identify and develop new sources of helium.
Helium gas has been produced from eight oil and gas fields located on the Four Corners Platform of northwestern New Mexico since 1943. Almost 950 MMCF helium have been produced from reservoirs of Permian, Pennsylvanian, Mississippian, and Devonian age on the Four Corners Platform in San Juan County. Concentration of helium in gases produced from these reservoirs ranges from 3 to 7.5 percent.
In northwest New Mexico, elevated levels of helium in natural gases occur not only in Paleozoic reservoirs on the Four Corners Platform but also in Paleozoic reservoirs in the deeper parts of the San Juan Basin located east of the Four Corners Platform. The regional set of orthogonal faults that offset Precambrian basement throughout the deeper parts of the San Juan Basin may have acted as migration pathways that transmitted helium from its basement source into overlying Paleozoic reservoirs.
Helium has not been extracted from produced gases in the New Mexico part of the Permian Basin where the concentration of helium in most reservoir gases is significantly less than 0.1 percent. However, gases with helium contents ranging from 0.3 to almost 1.0 percent occur in Pennsylvanian and Permian reservoirs along the northwest flank of the basin. The helium originated by radiogenic decay of Precambrian granitic rocks and migrated vertically into Pennsylvanian and Permian reservoirs through regional, high-angle, strike-slip faults. Known accumulations of helium-rich gases are located near these faults. In this area, Lower and Middle Paleozoic strata are only a few hundred feet thick, resulting in short vertical migration distances between the Precambrian source and helium-bearing reservoirs.
Other basins and areas in New Mexico are characterized by helium-rich gases and are of significant exploratory interest. These areas include the Chupadera Mesa region of eastern Socorro and western Lincoln Counties in the central part of the state, the Tucumcari Basin in the east-central part of the state, and a wide region across Catron and southern Cibola counties in the west-central part of the state. Elevated levels of helium are found in Pennsylvanian and Permian gases in these areas; gases with 3.5 percent helium have recently been discovered in Permian reservoirs on Chupadera Mesa. This is the highest known concentration of helium in any New Mexico gases outside of the Four Corners Platform.