Print this pageGeochemical Characterization and Relationship of Oil Seeps and Source Rocks from Northern Tunisia
SAIDI, M., and PHILP R
The petroleum potential of northern Tunisia has been demonstrated by the presence of numerous surface seepages of oil and gas in the region as well as many potential source rocks, ranging in age from Early Cretaceous to Eocene as indicated by various geological and geochemical studies. The four main source rocks in the region which can be distinguished are the Upper Barremian, the Albian-Vraconian, the Cenomanian-Turonian and the Ypresian. All four of these source rocks are organic rich and comprise predominantly Type II organic matter and are in the oil window. This paper will present the results from the geochemical characterization of 6 potential source rock samples and 6 oil seep samples. The major goals of tills study were to characterize the source rock samples in terms of organic matter content and maturity and to undertake oil/source rock correlation studies to try and delineate the origin of the oil seeps in this area.
As a result of this study it was possible to demonstrate a significant distinction between the samples on the basis of the geochemical characteristics, which permitted them to be grouped into 3 major families: (1) Family I included the Zag Et Tyr oil seep and the Cenomanian-Turonian source rock (Bahloul Formation), (2) Family II included the Bou Gotrane oil seep, Kasseb Dam oil seep and the Ypresian source rock (Bou Dabbous Formation), and (3) Family III included Jebel Ec Cheid, El Harroun and Slouguia oil seeps and the Upper Barremian (M'Cherga Formation) and the Albian-Vraconian (Lower Fahdene Formation) source rocks, which from a geochemical viewpoint are very similar.
In conclusion it can be stated that the occurrence of these source rocks close to numerous potential reservoir facies support the fact that the Northern Tunisia is very interesting and prospective area for petroleum efforts.