Skip to Main Content
Book Chapter

Carbonate Sedimentary Rocks and the Origin of Heavy Crude Oils

Irving A. Breger
Irving A. Breger
U.S. Geological Survey Reston, Virginia
Now deceased.
Search for other works by this author on:
January 01, 1984


Questions concerning the origin and constitution of so-called heavy crude oils have multiplied immensely with escalating interest in recovery of these oils. Although defining the term heavy crude oils presents a major and as-yet-unsolved problem, substances such as naturally occurring tars, asphalts, and bitumens are all considered to be expressions of heavy crude oils and are so treated in this presentation. Much evidence indicates that some heavy oils are residues of biodegraded conventional oils or are conventional oils from which the light ends have been stripped. On the other hand, such observations do not readily explain the origin of all heavy oils, among which are those found at great depth where neither biodegradation nor evaporative stripping is a likely mechanism.

The association of vanadium and sulfur with heavy crude oils also suggests that many such oils may have been formed by mechanisms other than those thought to be basic to the origin of conventional oils. In particular, evidence has recently been accumulated to show that carbonate rocks may be source beds for many heavy crude oils and that mechanisms leading to the direct formation of heavy oils are probably unlike those by which conventional oils are formed. Moreover, oil formed in carbonate sequences may have accumulated in source-bed reservoirs if conditions of porosity and permeability were appropriate.

You do not currently have access to this article.

Figures & Tables


AAPG Studies in Geology

Petroleum Geochemistry and Source Rock Potential of Carbonate Rocks

James G. Palacas
James G. Palacas
Search for other works by this author on:
American Association of Petroleum Geologists
ISBN electronic:
Publication date:
January 01, 1984




Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal