Where is the helium hideout?

    Helium is an extremely light, colourless, odourless and tasteless monatomic gas. As a noble gas, it has an extremely low boiling point and is chemically inert. It has become a valuable commodity in the field of cryogenics and is widely used in nuclear research and development, fibre optic electronics, superconductor research, space technology and other fields. The amount of helium in air is extremely low, only 5 parts per million by volume in dry air. The cost of extracting helium from air is so high that the primary source of helium is not air but natural gas. Due to its intrinsic properties, helium cannot normally be stored separately. Currently, most known helium resources are in the form of components of natural gas or associated gas. When the helium content of natural gas reaches industrial levels, this type of gas is known as helium-rich natural gas.

    Where does helium come from? Research has shown that helium in natural gas comes from two main sources: crustal and mantle. Mantle helium is a primordial gas that was trapped in the mantle during the Earth’s formation and can either migrate through deep faults or rise into the crust as a result of melting and volcanic activity. Helium is of crustal origin and is produced by the decay of radioactive elements in rocks, mainly granite. Both crustal and mantle-origin helium become part of the natural gas after production, migrating with the gas and accumulating in reservoirs after encountering favourable traps. China has some helium resources. Since the helium content of natural gas is generally low, with an average content of not more than 400 PPm, the simple extraction of helium from natural gas with low helium content requires a large number of process equipment, long technical routes and very high costs, which are inconsistent with the current scientific, technological and economic development of China. Therefore, there is an urgent need to study the exploration and development technologies suitable for helium resources from natural gas in China in order to provide resources for healthy socio-economic development during the 14th Five-Year Plan period.