GEOLOGY OF THE NORTH TUMACO BASIN: A REVIEW OF OIL INFORMATION PRE STRATIGRAPHIC DEEP-WELL DRILLING

Tumaco Basin is a fore arc Basin type associated with Tertiary subduction system. Structural styles onshore are essentially thrusting faults and in the offshore part of the Basin is more extensional type. In this Basin the upper Cretaceous rocks outcrop are those which form the basement and Cenozoic sedimentary rocks from the Eocene to the Pliocene, deposited in deep marine environments. The petroleum system in this Basin has been tested without success for over 30 years by several exploratory wells that have drilled basement highs related to diapirism. Just a few only a registered shows of condennate non-commercial gas has been recovered. Because of its sedimentary and tectonic features this basin has greater chances of stratigraphic traps than tectonic traps because of the turbidites deposited in the slopes of this basin. Main target of perforation of stratigraphic well ANH-BVTURA-1-1-ST-P, is to sample the stratigraphic column to a depth of about 3.048 m (10.000 ft) for getting a better understanding of the petroleum system in the area. Keywords: Tumaco Basin, stratigraphic deep-well, sedimentary environments, structural geology, well correlation