Drew Pomerantz, Schlumberger
Unconventional hydrocarbon resources such as gas shale and oil-bearing shale have emerged recently as economically viable sources of energy, dramatically altering America's energy landscape. Despite their importance, the basic chemistry and physics of shales are not understood as well as conventional reservoirs. In particular, shales are unique in that they contain kerogen, a complex organic solid that controls factors such as the amount of hydrocarbon that can be produced from the reservoir and the rate at which the hydrocarbon is produced. The industry's current understanding of the chemical composition of kerogen is limited, preventing detailed scientific study of the mechanism of production from shale. A broad effort is now underway to characterize kerogen, a task complicated by the fact that kerogen is an insoluble, non-volatile, complex mixture not amenable to analysis by the many liquid- and gas-phase analytical techniques commonly applied in the petroleum, chemistry, and biochemistry communities. X-ray Raman spectroscopy (XRS) is a novel approach to kerogen characterization with the potential to identify some aspects of the molecular architecture of fused aromatic rings dominant in kerogen. Here we will present XRS measurements of model compounds and a wide variety of kerogens, and we will draw some conclusions about the dominant forms of aromatic units in kerogen.
