The SORBED SOIL GAS method used by GMT, first developed by Horvitz (1939, 1985) and later modified by Phillips Petroleum, is also know in the industry as absorbed gas, Horvitz Absorbed Gas, acid-extracted gas, bound gas, or desorption gas.
This exploration technology is based on the observation that light hydrocarbon gases migrating upward from buried reservoirs become absorbed onto clays or incorporated into carbonate cements in near-surface soils and sediments. Areas of microseepage are detected by observing the concentration and composition of light hydrocarbons extracted from these soils and sediments.
There is often a direct relationship between the subsurface hydrocarbon accumulation and the concentration of these sorbed soil gases in the near-surface.
The “SSG” method detects the concentration of C1 Methane, C2 Ethane, C3 Propane, C4 Butanes, and C5+ hydrocarbons.
The sorbed soil gas method is an integrated method, recording hydrocarbon seepage from a time period of years to centuries.
Sorbed Soil Gas Analyis Provides the ability to:
Discriminate biogenic from thermogenic hydrocarbons
Differentiate between associated and non-associated gases
Estimate thermal maturity of migrating hydrocarbons
Correlate near-surface hydrocarbons with reservoir hydrocarbons