Helium

Although the element was also recognized in the spectrum of the gases emitted by Mount Vesuvius in 1882, it was not until 1889 during experiments conducted by William F. Hillebrand, that a sample of helium gas was finally obtained from uraninite. The experiments were repeated, at Uppsala by Per Teodor Cleve and Nils Abraham Langer in 1895, leading to a measurement of helium’s atomic weight.

Helium is a monatomic gas at temperatures above 4 degrees Kelvin. With an atomic number of 2 and an atomic mass of 4 (or more rarely, 3), it has the smallest atomic radius of any element, 31 picometers. Helium is the second most abundant element in the universe after hydrogen, but it is exceedingly rare on Earth; the atmosphere contains approximately 5.2 parts per million, the Earth’s crust approximately 8 parts per billion and seawater approximately 4 parts per trillion.

Major helium bearing natural gas fields in the United States. Courtesy of USGS.

Despite the rarity of helium on Earth, it is in some places concentrated. Natural gas deposits commonly contain trace amounts of helium in the parts per million, yet a few are known to contain up to 10-percent helium.

From Commoditization to Crisis

It was the accidental discovery of one such helium-rich natural gas accumulation at Dexter in Kansas, in 1903 that started the Unites States’ helium boom. Little more than a novelty when first discovered, helium has become a key commodity. It is used extensively in medical cryogenics (particularly in magnetic-resonance imaging machines), analytical and lab applications, breathing mixtures, as a lift gas, for arc welding, leak detection and, contrary to popular belief, only a little (less than 10 percent) is used to inflate party balloons. There are few substitutes for helium and so, as its applications have become more common, demand has grown and supply is struggling to match demand.

The discovery at Dexter, followed by others in the Midwest, has allowed the United States to dominate the helium market since it began. However, new discoveries have not replaced the volume of helium used, and recycling is rarely possible. Helium will inevitably leak from any container due to its small atomic radius. Once free, it is lost to outer space – it is not confined to Earth by gravity.

While the United States’ dominance of the helium market has declined, that of Algeria, Russia and, in particular, Qatar has risen as they too began discovering helium-bearing natural gases. Only 0.3 percent helium in a natural gas deposit will render helium the most valuable component. However, for one particular field, extracting the helium present at 0.04 percent concentration has proven economically feasible.

Many would regard this diversification of helium production as beneficial, but experience is already demonstrating that such diversification has not eased security of supply issues. From 2010 onward, several warnings about a helium supply crisis have been issued. These led cryogenics companies to issue supply curtailment notices to industrial and academic customers. It is easy to imagine the knock-on effects of this and, while few may worry about limiting the supply of party balloons, restrictions on use of medical scanners because of helium shortages could have fatal consequences.

From Accidental Discovery to Exploration

It is against this complex backdrop that we decided to find a new helium province. Initially, we were astonished to discover that there was no existing helium exploration strategy. The choices available were either drilling adjacent to a known helium accumulation, or fortuitously discovering economic concentrations of helium while exploring for petroleum.

We changed that.

Late in 2015, following an approach from Thomas Abraham-James and Josh Bluett of Helium One, we sampled gas seeps from Tanzania within the East African Rift System. We were confident of its potential from hints of helium in previous literature and our understanding of the helium system.

To understand how the Tanzanian discovery stands out, let us take a look at the unusual world of helium discoveries.

Bo Sears, in the book, “The Future of Helium as a Natural Resource,” recounts the story of that first well in Dexter, Kan. It was drilled just off the main street in Dexter by the Gas, Oil and Development Company. They hoped to find oil and/or natural gas and indeed hit a large reservoir of gas at 400 feet. There was much excitement in the town and people gathered, eager to see and hear the gas stream ignited, but the flame used to ignite the new-found gas was quickly extinguished. A second try was made to ignite the gas; it too failed.

Intrigued, the Kansas state geologist Erasmus Haworth sampled the gas and sent it to David F. McFarland at the Chemistry Department of the University of Kansas. McFarland published the results of the analysis in 1903 and of other natural gas accumulations from the Midwest in 1907.

The non-flammable gas sampled at Dexter was mainly nitrogen (82.7 percent) with some methane present (16.85 percent). The third most abundant component was helium at 1.84 percent. Of the other wells tested only the nearby Greenwell well at Dexter was of similar composition with 1.64 percent helium.

A couple of wells at Eureka, about 70 miles north of Dexter, also had more than 1 percent helium. Elsewhere in Kansas, Missouri and Oklahoma, helium abundance varied between about 0.2 and 0.5 percent. In all instances, including those from Eureka, methane was the most common component.

Interest in helium waned due to a lack of commercial applications for the gas.

This all changed in 1914 when the German chemist Géza Austerweil published “Die Angewandte Chemie in der Luftfahrt” (“Applied Chemistry in Aviation”). Austerweil highlighted the utility of helium as a buoyant, non-combustible gas for filling military balloons.

His report might have gone unnoticed if not for another event that year. In 1914, Allied aircraft attacked a German zeppelin. Incendiary bullets penetrated the airship’s skin, but it did not catch fire. The incident led some British scientists to conclude that Germany had found an abundant source of helium. This source was suspected to be either the coalmines at Anzin in France or Frankenholz in western Germany, which were known to have produced helium at rates estimated to be around 4,000 cubic meters a year. Despite the mistaken identity of the gas – for it was hydrogen in the blimp, not helium – these events prompted the first conscious search for large volumes of helium.

William Ramsay who, in 1904, had received the Nobel Prize for his work on the noble gases, led the search for “British” helium. The search proved unsuccessful in England and it was extended to Canada. Subsequently, J.C. McLennan, a professor at the University of Toronto, discovered helium concentrations of 0.1 to 0.33 percent in several natural gases from eastern Canada.

Once the military application of helium was recognized, the U.S. Geological Survey was tasked with investigating helium resources.

By 1921, helium had been found in natural gases from Kansas and northern Oklahoma, Texas, Ohio and Montana in reservoir rocks ranging in age from Silurian to Cretaceous, and at concentrations between 0.25 and 0.5 percent. A few gases with helium concentrations in excess of 0.5 percent were also found.

The most significant commonality of the discoveries was the occurrence of Precambrian granites and metamorphic rocks beneath them. This is true in Texas and Kansas and inferred from outcrop geology in Ohio. A further observation was that while nitrogen was always present in helium discoveries, nitrogen-rich natural gases did not necessarily contain helium.

The USGS also reported on helium discoveries elsewhere in the world. In Europe, small quantities of helium were found in natural gases in Italy, Hungary, Austria, Romania and Germany, as well as that already mentioned for France. Little information was available on the reservoir geology of these discoveries. The Survey noted that the helium content was very low in all but one European locality at Pechelbronn in Alsace (France), where helium was measured at 0.38 percent.

With helium present in such low concentrations, all “helium discoveries” require the gas to be processed to increase the helium concentration. The presence of helium in eastern Canada led to the development of the world’s first helium refining plant in Hamilton, Ontario. The L’Air Liquide Company modified an air separation unit and was able to produce helium at 87-percent purity with most of the remainder being nitrogen.

American Helium Dominance

The story of helium exploration in the 20th century belongs to the United States, and to the Midwest in particular, so it is here that we return after the end of the First World War. During the war, around 200 million standard cubic feet of helium had been produced from the Petrolia Field in Clay County, Texas. It was the mainstay of helium production in the United States, and to meet production requirements, a full-scale helium plant was built at Fort Worth, Texas by the U.S. Navy. However, production from the Petrolia Field was in decline by the 1920s, and by the time the field was shut-in in 1929 the plant had processed approximately 46 million standard cubic feet of helium.

Five years earlier, in 1924, the Cliffside Field had been discovered a few miles northwest of Amarillo in the Texas Panhandle. It contained approximately 1.8 percent helium and substantial reserves, leading the U.S. government to build a processing plant in nearby Amarillo. The rising demand for helium during World War II was supplied by the discovery of helium in the nearby Panhandle Field in Texas, the Otis and Cunningham fields in Kansas, and the Rattlesnake Field in New Mexico.

Despite the successful discoveries, the U.S. government recognized that the conservation of indigenous helium resources was now necessary. It was also realized that substantial quantities of helium had unintentionally been vented from fields produced for methane. Thus the U.S. Bureau of Mines undertook a systematic survey of helium in producing gas wells, pipelines and natural gas seepages across the United States. More than 3,000 gas analyses are reported in two bulletins. The states in which helium was found in one or more gas sample in excess of 0.3 percent (the current economic threshold for separation of helium) included: Arizona, California, Colorado, Illinois, Indiana, Kansas, Kentucky, Michigan, Montana, New Mexico, Ohio, Oklahoma, Texas, Utah and Wyoming. However, only in Arizona, Colorado, Kansas, Michigan, Montana, New Mexico, Oklahoma, Texas and Utah (the Riley Ridge Field in Wyoming joined this group in 2011) did some samples exceed 1 percent helium. Thus the importance of the Midwest as the world’s most prolific helium-producing region was proven.

That said, eight gas samples of 78 from Montana recorded 0.3 percent helium or greater with a peak of 3.91 percent from the Root No.1 well, Kootenai Dome, Fergus County and together with the Havre Field, also in Montana, and Bow Island in the adjacent Canadian province of Alberta a second petroleum province also emerged.

Mention should also be made of Michigan in which 39 samples out of 52 measured returned helium abundances of 0.3 percent or greater with a peak value of 1.11 percent in the Scipio Trend, the most bizarre oil discovery ever made. The Albion Scipio Field was discovered in fractured Silurian carbonates. The discovery well was drilled at a location dictated by the local clairvoyant after the interpretation of a dream experienced by the landowner. Ironically, it took geophysicists several decades to find the second field on the trend!

Following the Bureau of Mines reviews, Cliffside became the most important helium storage site in the world. By 1963, the U.S. government had begun to inject crude helium into the field from other fields in the United States. Crude helium is described as a helium-enriched, helium-nitrogen mixture obtained during first stage separation of helium-bearing natural gases.

Parts of Kansas and adjoining areas in Texas and Oklahoma have remained the most important areas for helium extraction, with the largest field being the Hugoton-Panhandle Field. Spanning Kansas, Oklahoma and Texas, the gas in the field contains 0.2-1.18 percent helium and is reservoired in Permian carbonates sealed by anhydrite in a combination stratigraphic (Hugoton)-structural (Panhandle) trap. The Hugoton-Panhandle of Kansas, Oklahoma and Texas, along with the Panoma, Kan.; Keys, Okla.; Panhandle West, Texas and Riley Ridge, Wyo. fields are estimated by the USGS to contain 97 percent of the United States’ 3.9 billion cubic meters of helium.