STONY RIVER TWP- A 2011 discovery southeast of Babbitt may lead to production of one of the highest-demand natural commodities in the world: helium. While helium is the second-most abundant element in the universe, most of it is trapped inside stars. Helium deposits here on Earth are much rarer.
The introduction of scientific equipment using helium has grown dramatically over the last half century, driving an increasing demand for the gas. The unexpected helium discovery in Lake County has put the region’s Duluth Complex rocks on the maps as a target for exploration for this strategic commodity.
The story of how the helium was found is now well known throughout the Arrowhead region. A drilling crew collecting cores for copper and nickel exploration hit an unexpected gas pocket that shut down the drill rig for five days. After the hole was capped, the exploration team had the gas analyzed. The results show it was mostly carbon dioxide, with significant fractions of nitrogen, methane, and a helium content of 10.5 percent.
The concentration of helium was astonishing to geologists because most commercial helium is derived from natural gas where typical concentrations of the gas average between 1 to 0.5 percent. The find was also unusual because of the age of the rock hosting the helium reservoir. The gas pocket was in the Precambrian Duluth Complex, some of the oldest rocks on earth.
Seismic results
Pulsar Helium, a Canadian company traded on the Toronto TSXV exchange, owns the private mineral leases that cover the deposit. The firm began a sophisticated passive seismic tomography survey of the resource in August and announced the results on Dec. 5. The survey found reduced shear wave velocities, which is a phenomenon indicating rocks saturated with gas.
The size of the anomaly, which corresponds with the gas pocket itself, is substantial, which has encouraged Pulsar to step up its exploration of the resource. “The results of the passive seismic survey exceed our expectations,” said Pulsar’s President and CEO, Thomas Abraham-James. “This suggests that we are looking at a reservoir with the potential for regional scale.”
The seismic survey that Pulsar used is state-of-the-art. Their survey did not use the invasive active blasting or massive vibrating trucks used in large-scale oil and mining exploration. The equipment utilizes passive seismic waves produced by local ground disturbances like blasting at iron mines in the Range and large trucks driving on local roads. The recorded seismic energy was then analyzed using a finite difference analysis known as tomography, which is the same technique used by medical magnetic resonance imagery, or MRI.
Pulsar will be conducting further exploratory drilling beginning in February to characterize the size and nature of the reservoir, which is hosted in a layered gabbro known as the Bald Eagle Intrusion, which is one of many such bodies in the Duluth Complex. Instead of using the usual diamond drill rig characteristic of mining exploration, Pulsar is bringing a big mud-rotary drill rig typical of those used for oil and gas exploration. The reason is simple: this type of rig is equipped to deal with high-pressure gas pockets, unlike a diamond drill rig used to core rocks. The use of a large exploration-grade mud-rotary rig may be a first for northeast Minnesota.
Helium use
Pulsar’s pursuit of helium is a smart move given the current high demand for the gas. The largest use of helium in the U.S. is for medical magnetic resonance imaging, or MRI. According to the U.S. Geological Survey, MRIs utilize 30 percent of all domestic helium sold. Lifting gas for blimps, zeppelins, and other lighter-than-air aircraft takes up 17 percent. Around 14 percent goes to analytical and laboratory equipment and nine percent is used for welding. Engineering and science applications use six percent, while semiconductor manufacturing uses about five percent of the nation’s supply.
The need for helium in electronics manufacturing and for cooling superconducting magnets in equipment like MRIs is a recent development of the last 30-40 years and the demand from both sectors is still growing. Before the advent of these sophisticated technologies, the primary use of helium was for lifting gas.
For most of the 20th century, helium was a fiercely protected strategic commodity because of the military use of blimps and zeppelins. At the time, the U.S. dominated the global helium market and controlled the world’s supply for decades. One of the indirect causes of the hydrogen-fueled explosion of Hindenburg zeppelin in 1937 was the United States’ refusal to sell explosion-proof helium to Nazi Germany.
The nation’s helium dominance had its roots in the helium-enriched oil and gas discoveries in the Texas and Oklahoma panhandles. The helium content of natural gas from Panhandle area fields averaged 0.5 percent, which was the highest concentration known at the time of its discovery in 1920. The early military demand for helium made the separation of helium from natural gas economically feasible.
Those oil and gas fields along with others like them in Kansas, Colorado, Utah, and Wyoming, still have the most helium-enriched natural gas in the world and provides most of the helium sold in the U.S. Even today, the U.S. has the most helium still in the ground, estimated at 53 percent of the world’s total reserves.