Molecular and Isotopic Analyses of the Hydrocarbon Gases within Gas Hydrate-Bearing Rock Units of the Prudhoe Bay-Kuparuk River Area in Northern Alaska

Gas characteristics analyzed include nitrogen, carbon dioxide, methane, ethane, ethene, propane, propene, isobutane, n-butane, isopentane, n-pentane, stable carbon isotope composition of the methane, ethane, and carbon dioxide fractions, and deuterium isotope composition of the methane fraction. Methane is the most abundant hydrocarbon gas within the gas hydrate- bearing rock units of the Prudhoe Bay-Kuparuk River area in the North Slope of Alaska.

Isotopic analysis indicates that both microbial and thermogenic processes have contributed to the formation of this methane. The thermogenic component probably migrated into the rock units from greater depths, since vitrinite reflectance measurements show that the units never endured temperatures within the thermogenic range. Approximately 50 to 70 percent of the methane within the gas hydrate units is thermogenic in origin.

This is U.S. Geological Survey Open-File Report 92-299 This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.