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Since August 1982, the CFA 1 Scott well in Sec. 20, T14S, R6E, Morris County, Kansas, located about 14 mi (23 km) south of Junction City, has yielded a gas composed of 50± 10% free hydrogen, 50± 10% nitrogen, and only traces of hydrocarbons. This analysis has been ascertained by gas chromatography and mass spectrography of samples taken over a period of 6 months. The reservoir rock is a "Kinderhook" sand from 2,176 to 2,196 ft (663 to 669 m) depth. The gas samples analyzed are accumulating in the head space above a fluid level (salt water) of 1,805 ft (550 m) from a bottom-hole depth of 2,197 ft (670 m).
The Scott well is located on the western flank of the complexly faulted Nemaha anticline, updip from the central North American rift system and 30 mi (48 km) south of Riley County where serpentinized kimberlites occur. The geothermal gradient is 30°C/km (87° F/mi). Basement rock beneath the well is granite, probably overlying deeply buried magnetic rocks.
Bulk composition of gas from the Scott well is similar to H2-rich gases issuing from hydrothermal vents at the 21°N site on the East Pacific Rise, and to certain gases occurring within the Zechstein strata of Poland.
Mechanisms proposed by others to explain the origin of naturally occurring free hydrogen include: bacterial or inorganic decomposition of organic matter; bombardment of organic matter by radioactive decay products; high-temperature magmatic and volcanic processes; dissociation of H2O by low-temperature or metamorphic reactions involving sulfur species of the Fe+2 ^rarr Fe+3 redox half reaction (e.g., during serpentinization of ultramafic rocks), and mantle out-gassing of primordial reduced gases. For some wells, artificial production of H2 (e.g., oxidation of iron tools or pipe), also has been proposed to occur. Light, stable, isotope ratios (e.g., D/H, 18O/16O, and 15N/14N) may be distinctive suff ciently to rule out certain of the proposed H2-generating mechanisms.
No single mechanism is responsible solely for generating this H2-rich gas from the Scott well; rather, a combination of fortuitous geologic and possibly biologic processes are contributing in various proportions to the production of the H2 and N2. Conceivably, the local geologic setting merely is circumstantial and unrelated to the genesis of the gases. However, in view of its spatial association with the central North American rift zone, a major geologic feature with similarity to the East Pacific Rise, the Kansas gas occurrence warrants additional study.
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