Henry's law and accumulation of weak source for crust-derived helium: A case study of Weihe Basin, China

Isotopic Analyses of Helium From Wells Located in the Four Corners Area, southwestern, Us

“…According to Brown (2010), old stagnant water is more preferential than young hydrodynamic water in this step as more ancient solutions (>100Ma) should have a more significant percentage of dissolved He in the solution without being overly diluted. This step involves enrichment of helium by means of partitioning out of water (due to a decrease in He partial pressure) into the gas phase by being stripped by other carrier gases (Brown, 2010;Li et al, 2017). Danabalan (2017) argues that depending on the degrees of saturation of the pore-water, helium may not need a carrier gas to come out of a dissolved solution.…”

“…For example, if the solution were oversaturated (or other parameter changes such as pressure decrease, water temperature changes, and salinity changes), He would exsolve independently. Conversely, another instance is that if helium is not so enriched, a migrating gas phase would be required to aid in the partitioning of helium from the pore-water to the gas phase (Li et al, 2017). Specifically, the partitioning of helium out of solution occurs when a gas comes in contact with helium dissolved in pore water and due to phase differentials, the helium partitions into the gas stream (Li et al, 2017).…”

“…Conversely, another instance is that if helium is not so enriched, a migrating gas phase would be required to aid in the partitioning of helium from the pore-water to the gas phase (Li et al, 2017). Specifically, the partitioning of helium out of solution occurs when a gas comes in contact with helium dissolved in pore water and due to phase differentials, the helium partitions into the gas stream (Li et al, 2017). (Brown, 2010) X He refers to the molar fraction of He in an aqueous solution (water), and f He refers to helium fugacity (Brown, 2010).…”

“…H He is referred to as Henry's constant, a function of water salinity and temperature, that largely controls helium's partitioning into the gas phase. As one can see in Figure 3.4, Henry's constant for helium is >1, meaning helium will be concentrated into the gaseous state (Brown, 2010;Li et al, 2017). Brown (2010) also states that for helium, the greater Henry's constant is, the less soluble the species is, and thus the greater amount of the helium will be in the gas phase ( Figure 3.4).…”

“…Brown (2010) states that helium concentrations in the gas phases will be greater given there is less gas compared to water in the system. Furthermore, the migrating gas does not exsolve the helium out of solution by direct contact; a more accurate description is as helium is extracted from the pore water, diffusion occurs as helium in adjacent areas (several hundred meters above and below) migrates towards the gas stream (Brown, 2010;Li et al, 2017).…”