Abstract: Primary Migration--New Tack on an Old Theme

Jack Simmons

Hydrocarbon droplets small enough to migrate through source-rock pores contain too few molecules to follow fluid laws. Further, their solubility in water is greater than that of larger droplets, which should form a concentration gradient preferentially diffusing hydrocarbons toward larger pore spaces. Once emplaced, possibly as pools, the large size and corresponding low solubilities of the hydrocarbons tend to stabilize them against further solution movement. A sample calculation of such diffusion drive can account for the size of observed pools in the Gulf Coast.