RE: Helium trapped.23 Jun 2021 09:43
My reasoning..
I think if it was at the top you would sample/extract helium first, then eventually nitrogen from/at the crest
In the article the diagram shows one gas cap, not helium above nitrogen.
The its used "-" to combine the components of the gas phase, and only mention one gas phase
Our studies indicate that once helium and nitrogen are released from the source rock, they interact with groundwater in overlying strata (see figure above). Once enough helium and nitrogen are dissolved in the groundwater, they are able to form a separate "nitrogen- and-helium-rich" gas phase as the groundwater ascends to the surface and becomes depressurized. We think this is the mechanism for the near-pure nitrogen-helium gas fields found in North America.