Effects of geological processes and organic matter maturation on the potential hydrocarbon production in La Luna Formation

Abstract

Deposition of organic-rich rocks and C-isotope excursions from several Mesozoic sections around the world are consistent with widespread but short-lived deoxygenation in the ocean. These episodes, known as oceanic anoxic events (OAEs) played an important role in the deposition of source rocks. Oceanic anoxia is considered the main driver in the burial and preservation of organic matter leading to the deposition of black shales. My PhD research is focused on the La Luna Formation deposited in Colombia, 94 Ma, during the event known as Oceanic Anoxic Event 2 (OAE2). The La Luna Formation is well known for having elevated total organic contents, dominant kerogen types I and II, and organic matter rich in sulfur. However, how these features vary over time, and how they will affect the potential of the rock to generate hydrocarbons is still unknown. The aim of this proposal is to understand: 1) how euxinic versus suboxic conditions triggered an increase in TOC; 2) how TOC richness and S-rich rocks will affect the temperature of hydrocarbons production and the kinetic conversion of TOC to bitumen and oil during the event known as the Cenomanian-Turonian boundary Oceanic Anoxic Event 2. These questions will be addressed using a combination of organic geochemistry (rock-eval pyrolisis and elemental S composition or organic matter) and inorganic geochemistry (concentrations of redox sensitive trace elements and Fe-speciation). Results from this research have implications for the risk assessment of conventional and unconventional plays by improving the uncertainty associated with the real potential of La Luna Formation to produce hydrocarbons.

AAPG Datapages/Search and Discovery Article #90351 © 2019 AAPG Foundation 2019 Grants-in-Aid Projects