A hypothesis concerning the accumulation of sediment hydrocarbons to form crude oil

Abstract

Small amounts of hydrocarbons, similar to those present in petroleum, are known to be dispersed throughout Recent marine sediments. However, their importance as major constituents of crude oils, if present in a like manner in ancient sediments at the time of deposition, is still being debated. Only recently has the significance of the Recent sediment hydrocarbons been indicated by the demonstration that crude oils and the sediments being deposited today contain certain identical kinds of hydrocarbons. From an awareness of this close relationship and from a knowledge of the distributional differences which exist between Recent sediment and crude oil hydrocarbons, the process of forming oil appears mainly to be a physical one. Consequently, no extensive chemical alterations would be required by this hypothesis. A study of hydrocarbon solubility in dilute colloidal electrolyte solutions suggested the nature of the physical process by which sediment hydrocarbons may be selectively removed from the source sediments and deposited in the correct proportions to form crude oil. The process appears to involve the solution, migration and release of hydrocarbons in waters containing natural solubilizers. The similarity between the relative abundance of certain hydrocarbons in crude oil and the relative solubility of the same hydrocarbons in colloidal electrolyte solutions provides presumptive evidence that crude oils consist of Recent sediment hydrocarbons that were once solubilized in formation waters.