Gas exploration

Huge helium reserves in Tanzania

Print edition : July 22, 2016

A NEW approach to gas exploration has discovered a huge helium gas field, which could address the increasingly critical shortage of this vital yet rare element. Helium is critical to many things we take for granted, including MRI scanners in medicine, welding, industrial leak detection and nuclear energy. However, known reserves are quickly running out. Until now helium has never been found intentionally, only accidentally discovered in small quantities during oil and gas drilling.

Now, a research group from Oxford and Durham Universities, working with Helium One, a helium exploration company headquartered in Norway, has developed a new exploration approach. The first use of this method has resulted in the discovery of a world-class helium gas field in Tanzania.

Diveena Danabalan of Durham University, who was involved in the research, said: “We show that volcanoes in the Rift play an important role in the formation of viable helium reserves. Volcanic activity likely provides the heat necessary to release the helium accumulated in ancient crustal rocks.” Within the Tanzanian East African Rift Valley, volcanoes have released helium from ancient deep rocks and have trapped this helium in shallower gas fields.

“However, if gas traps are located too close to a given volcano, they run the risk of helium being heavily diluted by volcanic gases such as carbon dioxide, just as we see in thermal springs from the region. We are now working to identify the ‘goldilocks-zone’ between the ancient crust and the modern volcanoes where the balance between helium release and volcanic dilution is ‘just right’,” said Danabalan.

Chris Ballentine of the University of Oxford, who was also associated with the project, said: “We sampled the helium gas (and nitrogen) just bubbling out of the ground in the Tanzanian East African Rift valley. By combining our understanding of helium geochemistry with seismic images of gas trapping structures, independent experts have calculated a probable resource of 54 Billion ft 3 [1 ft 3 = 0.03 m 3] in just one part of the rift valley. This is enough to fill over 1.2 million medical MRI scanners….This is a game changer for the future security of society’s helium needs.” Pete Barry, also of the University of Oxford, who sampled the gases, said: “We can apply this same strategy to other parts of the world with a similar geological history to find new helium resources.”

Compiled by R.Ramachandran