Helium is a low density, non-narcotic gas often added to the breathing gas mixture of divers who have to dive deep. Nitrogen, the primary component of air is both dense, making it hard to breathe when diving deep, and narcotic at depths below one hundred feet. That is why nitrogen leads to the so-called “rapture of the deep.” Narcotic divers make bad decisions.
If it weren’t for helium, some of the deepest and most sensitive diving for national security would never have happened. So, it’s really important. Commercial saturation diving in the oil fields of the North Atlantic and the Gulf of Mexico is wholly dependent on the easy to breathe and non-narcotic properties of helium.
Both civilian and government science divers, technical divers, and underwater cave explorers have been able to extend their diving range and safety because of helium in their breathing gas.
For those not familiar with the second lightest gas in the periodic table, I’ve included a Fast Fact from the Bureau of Land Management (BLM) at the end of this post.
There are two drawbacks to helium. A source of breathable helium is sometimes hard to locate, and the gas is expensive. Because of that expense and growing scarcity, it is forecast to become increasingly difficult to find, especially in remote locations.
The primary source of helium, a non-renewable resource, is from gas wells. As shown in the BLM summary at the bottom of this post, the demand for helium is high in scientific, medical, military, and commercial applications.
Not on the list, and the least likely to be considered during allocation of an increasingly scarce resource, is civilian diving, and perhaps even military diving.
The above graphical projection made in 2010 does not consider the damping effect of current government policies which make drilling oil and gas wells, and fossil fuels in general, undesirable. While Qatar and Russia have significant helium reserves, helium transported from distant countries will come with a much higher price tag than forecast in 2010. Unfortunately, no one has so far calculated the net cost of reducing the recovery of gas from the ground, and the recovery of the helium contained in that natural gas.
Why might the next century bring a lowering of helium prices as predicted in the graph above? As I’ve explained in Atmosphere, Book 3 of the Jason Parker Trilogy, fusion reactors should hopefully be common place by then, and helium is a byproduct of those fusion reactions. Of course, the above graph reflects a great deal of uncertainty about the next century, even without the uncertainty introduced by government policies. But our immediate concern is this century, not the next.
One approach to helium conservation is by using rebreathers to conserve gas rather than exhaust it into the water column, as is done in open circuit diving like that pictured in the first underwater photo with two Navy divers. In rebreathers, the only helium wasted is that used to keep breathing bags inflated on descent. Unfortunately, that gas is “burped-off” as gas expands on ascent. But the amount of inert gas wasted during rebreather operations is still far less than in open-circuit diving.
Another option for holding down helium cost, is to use helium in “Trimix”, a mixture of oxygen, nitrogen and helium. Such mixes become popular for use at depths of 200 feet sea water (fsw) and deeper. It minimizes the cost of helium while simultaneously reducing the effect of nitrogen narcosis.
A common trimix is called 21/35, which has 21 percent oxygen, 35 percent helium and 44 percent nitrogen. Another common mixture is 18/45, with 18 percent oxygen and 45 percent helium. Those helium percentages are considerably reduced from that found in a typical military heliox mixture containing no nitrogen.
But even then, using helium for recreational deep diving may become far too expensive for any but the richest recreational divers. Already, it’s reported that scientific and medical instruments like superconducting magnets and MRI machines have been affected by helium shortages.
When it comes to the DoD prioritization of military saturation diving missions compared to other military options, the availability and cost of helium will inevitability factor into the high-level decision tree.
So, is there an alternative to helium use in diving? Well, yes and no. I’ve written in both this blog and in my novels about the use of hydrogen in diving, as has a biomedical researcher friend of mine, Susan Kayar, Ph.D. in her novel, Operation Second Starfish.
Hydrogen is even lighter than helium, but at great depth it is narcotic. One strange thing about hydrogen narcosis is that at great depth it can result in psychotic manifestations in some individuals. Also, at shallow depth, hydrogen can form an explosive mixture with oxygen, an issue I’ll discuss in my next post. So, it has to be used with great care and attention to details.
Interestingly, the math says that at 200 fsw, the depth where trimix is typically used, hydrogen can be safely substituted for helium. However, only experimentation can prove if that prediction is valid or not. But as helium gets scarcer and more expensive, using hydrogen in place of helium is something worth considering.
[DO NOT CONDUCT YOUR OWN EXPERIMENTS WITH HYDROGEN. THERE IS ALWAYS A CHANCE OF INJURY OR DEATH WITH HYDROGEN. THINK OF THE HINDENBURG!]
Below are links to other hydrogen and forward-looking diving posts in this blog.
Helium Fast Facts
Fact Sheet—BLM New Mexico Amarillo Field Office
Helium: Questions and Answers
What is helium?
Helium is an odorless, colorless, and tasteless gas. Helium, more than 99.9 percent pure, is also used in liquid form at -452 degrees Fahrenheit.
Where does helium come from?
Helium occurs with other gasses in pockets beneath the Earth’s surface. The most economical source of helium is natural gas, all of which contains some helium. Natural gas in the States of Texas, Kansas, Colorado, Utah, and Wyoming is richer in helium than what has been recovered from other States.
How is helium produced?
When a gas pocket containing economically recoverable amounts of helium is found, a well is drilled to release the gas. It travels by pipeline to a processing plant where the helium is separated from the other gasses. One method of separation is a cryogenic process, which uses cold temperature differences to split the components. Another process, membrane filtration, uses molecular size difference to split components.
What is helium used for?
Today, helium plays a prominent role in medical imaging (magnetic resonance imaging), fiber optics/semiconductor manufacturing, laser welding, leak detection, superconductivity development, aerospace, defense, and energy programs.
Is helium renewable (does it naturally replenish itself after humans use it)?
No, helium is a non-renewable resource. That is why the Federal Government stored 44 billion cubic feet of helium in a natural gas reservoir at Cliffside, just outside of Amarillo, Texas. Helium was injected into porous rock 3,000 feet below the Earth’s surface during the 1960s. This rock holds gas like a sponge holds water. Two layers of calcium anhydrite cover the rock, acting as a lid. The sides are surrounded by water.