Applications of Stable Isotopes in Hydrocarbon Exploration and Environmental Forensics

Abstract

Hydrocarbon exploration and environmental forensics may appear to be two unrelated topics but in many ways are closely related. Techniques that have been developed and utilized in the hydrocarbon exploration and exploitation industry for many decades have found their way to the forefront of environmental forensics area over the past decade. Whereas hydrocarbon exploration is geared towards finding new resources, environmental forensics is directed to looking at what happens to those resources as they, or products derived from them, are spilled into the environment. In the former one uses sophisticated techniques to correlate oils, or gases, with their suspected sources and in the later, one is trying to correlate the spilled product with its suspected source. The source may be a tanker, pipeline, underground storage tank or something similar. The most widely used techniques in both of these areas for many years have been gas chromatography (GC) and gas chromatography mass spectrometry (GCMS) but recent years have seen an exponential increase in the utilization of stable isotopes. There is nothing new about applying stable isotopes to exploration problems but the majority of the older applications utilized bulk isotope numbers for crude oil correlation studies. The availability of the combined gas chromatography-isotope ratio mass spectrometer systems (GCIRMS) over the past 10–20 years, has played an important role in the increased number of applications where stable isotopes have to be used to investigate problems in both of these areas. In this chapter, we examine developments and applications in hydrocarbon exploration and environmental forensics. In addition areas that are currently just starting to emerge particularly in the area of environmental forensics will also be discussed.