Obscure Nature of Petroleum Migration and Entrapment

Abstract

A comprehensive explanation of petroleum migration and entrapment requires free passage of both petroleum and water through fine capillaries. Because of the immiscibility of these fluids, severe flow resistivity attributable to high interfacial tension develops within low to medium ranges of temperature and pressure. A means by which these flow-resisting forces might be reduced within the high temperature and pressure ranges of a petroleum-migrating environment deserves consideration. Modest alterations in the bulk composition of different phases containing chemically dissimilar molecules might alter substantially interfacial tension much as the admixture of differing molecules can lower profoundly the surface tension of a solvent. The composition of discrete phases might vary substantially within the high temperature and pressure ranges now thought to characterize the environment of petroleum migration. There also should be a markedly enhanced adsorption of dissimilar molecules along an interfacial zone of uncertain definition separating one phase from another under intense pressure. The possibility, under high temperature and pressure, of several phases having differing physical properties and minimal interfacial tension seems to emerge as a particular area worth investigating. Distinct, free-flowing phases with little interfacial tension may retain a capacity for gravity segregation, and a more complete explanation of petroleum migration and entrapment may be possible.