Dr Anran Cheng (Department of Earth Sciences, University of Oxford), lead author of the study, said: ‘Our model shows the importance of factoring in the high diffusivity of helium and the long timescales needed to accumulate significant gas quantities, and the fact that the entire geological system acts dynamically to affect the process.
Dr Anran Cheng (Department of Earth Sciences, University of Oxford), lead author of the study, said: ‘Our model shows the importance of factoring in the high diffusivity of helium and the long timescales needed to accumulate significant gas quantities, and the fact that the entire geological system acts dynamically to affect the process. This model provides a new perspective to help identify the environments that slow helium gases down enough to accumulate in commercial amounts.’
Where rare helium-rich underground gas fields have been found, they always occur alongside high concentrations of nitrogen gas. Until now, there has been no explanation for this. For the first time, this new study, which also involved the University of Toronto and Durham University, provides an answer.
The research team built a model to account for these helium-rich deposits by (for the first time) factoring in the presence of nitrogen, which is also released from the deep crust along with helium. The authors identified the geological conditions where the concentration of nitrogen becomes high enough to create gas bubbles in the rock pore space.
Read more at: University of Oxford
Dr Anran Cheng (lead author, left) and Professor Chris Ballentine (right) preparing equipment for measurement of helium isotopes in geological samples. (Photo Credit: Sarah Hilton)
