Helium Exploration

Back in my high school days, I never really gained a full appreciation for inert gases; heck, I never really gained a full respect for Chemistry as a whole. I found that Chemistry cut into my horseplay time, and this usually led to grief that followed in the form of studying and having to write an exam. Today, having an interest in the exploration of natural resources I find myself studying the extraction of helium. Before I embarked on this mission I really didn't have a clue; yeah I heard of oil and gas exploration, but helium? Sure, the stuff which makes balloons rise and is often used as an old party trick to change the pitch of your voice. At that time that was essentially the extent of my knowledge on helium, how enlightened I was once I began research into the subject.

Helium is an inert/noble gas which includes the O group elements on the periodic table. Inert gases are colorless, odorless, tasteless, and cannot form chemical compounds naturally. Inert gases have a full valence shell, meaning they are in a constant, stable configuration. Since inert gases already have a full valence shell, they cannot donate or accept electrons. They cannot react -this is key to many applications of inert gases.

Helium forms by the radioactive decay of uranium and thorium. Radioactive decay is a natural process. An atom of radioactive isotopes will spontaneously decay into another element via one of three ways: alpha decay, beta decay, or spontaneous fission. Four kinds of radioactive rays are emitted upon decay: alpha rays, beta rays, gamma rays, and neutron rays. In the case for helium, uranium and thorium undergo alpha decay, thus giving off alpha particles. These alpha particles are helium nuclei which are composed of two protons and two neutrons bound together. If there is no carrier available, the helium nuclei will eventually migrate to surface where they are expelled into the atmosphere. If these helium nuclei are to be trapped they are entirely dependent on a carrier, such that hydrocarbons can provide.

Helium is strongly associated with hydrocarbon deposits. It has been noted to be particularly enriched in gas-oil reservoirs, more so than in dry gas reservoirs (Nikonov, 1973) It is also particularly enriched in reservoirs having a high nitrogen content. This in turn makes helium exploration less risky in that if the hydrocarbons found are poorly saturated with helium, one can still produce the hydrocarbons.

Helium has many industrial uses. The basic and most common ones are as follows: In making balloons and air ships rise (Figure 1), as shielding agent in high quality arc welding of stainless steel, aluminum, and copper, as shielding agent used to protect the growth of industrial silicon, as in the production of titanium and zirconium, as an excellent cooling agent in sensitive nuclear reactors because of its extremely low boiling point, rapid diffusion property, and its radioactive immunity (Figure 2), as an effective and rapid detector of leaks in high vacuum and nuclear equipment since it diffuses readily , as in the pressurizing of ballistic missiles because of its low flammability and buoyant nature (Figure 3), in wind tunnels to test streamlines at extremely high speeds (Figure 4), in low temperature physics because of it is the only known substance which is able to reach temperatures approaching absolute zero, as an artificial atmosphere for divers and others working under pressure(80% helium and 20% oxygen), in Helium and oxygen mixtures that are used in aspirators for respiratory sufferers who need restricted and specific doses of oxygen. with some explosive anesthetics, which enable safe use in operating rooms (Figure 5), and as a carrier gas in gas chromatography.

The statistics on helium as of 1984 indicate that the United States, Poland, USSR, and India are the only known locations of active helium extraction plants (Figure 6). At the beginning of the 1960's, The USA was the only producer and processor of helium. Future analysts at the time predicted a rather diminutive life span of the existing helium resources. Today although more helium localities have been found, they are still restricted to a few regions around the world.

Helium is relatively cheap to process, with costs primarily associated with the gas pump operations needed to pump the gas mixture to be unmixed. Helium processing plants can be quite small in contrast to conventional processing plants and oil refineries. Remember that the exploration incentive lies in the fact that if the hydrocarbon found cannot have helium extracted from it, the hydrocarbon itself can most probably be produced.

References: Gold, T, 1993, USGS, 1993, Professional Paper 1570, The Future of Energy and Gases, The Origin of Methane (and oil) in the Crust of the Earth. Lee, H, 1962, Department of Minerals and Resources, Regina, The Technical and Economic Aspects of Helium Production in Saskatchewan, Canada. Sawatzky, H.G., Agarwal, R.G., Wilson, W, 1960, Department of Mineral Resources, Province of Saskatchewan, Helium Prospects in Southwest Saskatchewan.

Links which assisted in the writing of this paper: www.webelements.com www.praxair.com www.people.cornell.edu