Inorganic Tracers in Crude Oils: A New Method in Correlating Hydrocarbons to Organic Source Rocks: Woodford Shale, North-Central Oklahoma

Daniel Ramirez-Caro, Matthew Totten, Sambhu Chaudhuri, Norbert Clauer, Greg Riepl, John Miesse, and Rene Boutin

Oil-source rock correlation has been a useful tool to further our understanding of the genesis and migration of crude oil. Organic geochemical markers are most often used, which provides information on both thermal maturity and richness of a source rock. Almost no data exist on the concentrations of inorganic elements in crude oils or the organic fraction of source rocks. Concentrations of many elements are available on oil-field brines, however the data on rare earth elements (REE) and other metals (Pb, U, Th, K, Rb, N, V) are not well known. We have developed a method a t Kansas State University to determine the concentration of these elements in crude oils, and are investigating the possibility of finding a useful signature for oil-source rock correlation through these inorganic tracers. This project focuses on the geochemical analysis of the Devonian Woodford shale, located in the Anadarko Basin of Oklahoma. We present results from crude oil samples produced from the Woodford as well as overlying Mississippian reservoirs. Brines associated with these oils were also analyzed. Concentrations within the organic matrix of the Woodford Shale, and whole-rock data are also presented. Preliminary results suggest that this method is a promising addition to associating produced oils with their organic source rock. 

AAPG Search and Discovery Article #90176©AAPG Mid-Continent Meeting, Wichita, Kansas, October 12-15, 2013