Tectono-Stratigraphic Controls on Petroleum System Elements in Passive Margin Settings: Studies of the Western Nicaraguan Rise and the Deep-Water, Foz Do Amazonas Basin, Brazil

The Nicaraguan Rise is a Late Cretaceous (?) – Cenozoic, carbonate platform developed as a carbonate passive margin in an intra-plate setting while the Foz do Amazonas basin is a Jurassic to Recent dominantly clastic passive margin influenced by the world’s second largest river, the Amazon River. Hydrocarbon exploration on the Nicaraguan platform in the western Caribbean Sea and Foz do Amazonas basin in Brazil was very active from 1960 to 1980 with 2D seismic acquisition and exploratory drilling on both margins. Because prior exploration activities in both basins have not lead to major discoveries, both areas remain frontiers for petroleum exploration. This dissertation uses a total of ~29,500 km of 2D seismic data, and 30 exploration wells in order to understand the main tectonostratigraphic controls on the geologic history of the two margins and how their paleogeographic evolution has influenced their petroleum systems. The dissertation is divided into four chapters: Chapter 1: Introduction to the dissertation; Chapter 2: I present a sequence stratigraphic and paleogeographic reconstruction in the Nicaraguan platform. I identified three cycles of transgression and regression that occurred in a fragmented to continuous, mixed carbonate platform setting. I also propose stratigraphic, structural or combined Eocene to Miocene hydrocarbon plays for the Nicaraguan platform; Chapter 3: I conducted seismic interpretation, mapping, seismic facies analysis, and 2D kinematic restorations to propose a tectonostratigraphic evolution of the deep-water Foz do Amazonas. I identified five tectono-sequences: a) an Early Cretaceous, syn-rift, fluvio-deltaic system deposited in pull-apart basins, and charged by Albian-Aptian source rocks; b) “Tectono-stratigraphic succession II”: a Late Cretaceous to Early Paleocene, deep-water fan system charged by Cenomanian-Turonian source rocks; c) “Tectono-stratigraphic succession III”: a Late Paleocene to Middle Miocene, carbonate platform highly affected by gravitational collapses; and d) “Tectono-stratigraphic succession IV”: a Late Miocene to Recent, thick-clastic succession derived from the Amazon River, which is represented by a passive fold belt, the Amazon Cone, and associated mass transport deposits; and Chapter 4: I created risk maps of the petroleum system elements in both study areas by combining the geological characteristic and exploration results from Chapters 2 and 3.