Evaluating the temporal changes of the Woodford Shale paleoenvironment via amalgamation of organic geochemistry and sequence stratigraphy

Abstract

The primary focus of oil exploration is typically the yield from a successful well and often ignores why many wells are dry. A better understanding of what controls the formation of organic rich source rocks can greatly reduce the chances of drilling dry holes. Formation of organic rich source rocks and subsequent hydrocarbon generation is primarily controlled by two processes: productivity and preservation. Geological proxies are limited in resolution, such as vague inferences into the redox state of the water column. Biomarkers provide further insight into water column chemistry, shedding light on fine-scaled environmental intricacies. Carotenoids, an underutilized class of biomarkers, possess exceptional applications from a paleoenvironmental perspective. Previous work by Romero and Philp (2012) discussed carotenoid derivatives in the Woodford Shale and associated oils to understanding euxinia. The current paper expands on these results with the discovery of additional carotenoids aligned with a sequence stratigraphic framework to determine the potential of these compounds as indicators of eustatic fluctuations. The unique nature of these biomarkers could be advantageous when applied to exploration of similar shale plays. Prevalence of euxinic conditions in the geologic past will be discussed in this presentation with the Woodford serving as a useful analog of other shale plays from an exploration and environmental context.

AAPG Datapages/Search and Discovery Article #90221 © 2015 Mid-Continent Section, Tulsa, Oklahoma, October 4-6, 2015