Recognition of the geochemical effects of expulsion of petroleum from source rocks

The results of many years of geochemical studies carried out by the author's former group at the Research Center Juelich (KFA) are reviewed. This work includes case history studies of the geochemical effects of petroleum expulsion from mature source rocks as well as experimental studies to simulate petroleum migration under controlled laboratory conditions. Main emphasis is on a discussion of concepts and methods on how to recognize and how to quantify the effects of petroleum flow in fine-grained argillaceous rocks. Observations and conclusions about the role of micro-fractures in primary migration processes are also overviewed. (R.P.)