Gas: A Messenger From Subsurface Resources

Clean-burning, energy-rich natural gas is an increasingly desirable hydrocarbon resource. Gas can be retained in a basin for hundreds of millions of years (as in the Anadarko), yet vents almost continuously in active basins such as the Gulf of Mexico Basin. Five years ago the Gas Technology Insititute awarded a research contract to Cornell University to examine how gas moves in the deeper portions of a very active basin. Could the capillary forces that arise when gas is present in grain-sizelayered sediments produce the very low permeability surfaces, called seals, that divide basin interiors into compartments of variable and often very high overpressure, and could this affect gas and hydrocarbon migration? Laboratory experiments reported from a previous GRI-funded study suggested that this was possible (Shosa and Cathles, GCSSEPM, 2002). But could it be demonstrated in the field?