ABSTRACT

Petroleum geochemistry is the outgrowth of the application of the principles and methods of organic chemistry to petroleum refining and to petroleum geology. Concepts in petroleum geochemistry have continually evolved, enhanced by the development of new analytical techniques, leading to new discoveries concerning the origin and occurrence of petroleum. The concepts are applicable to all areas where exploration and production is underway. In mature regions more emphasis should be placed upon the applications of these concepts to improving production and recovery. It may also provide information on regions previously overlooked but which may, as a result of improved technology, actually be economic to produce. In frontier areas geochemistry is invaluable in providing information that may be used to evaluate the potential of a new area for production of oil and gas. There are many questions to address that result from development in other areas. For example why are oils being produced from depths of 500 to 700 ft in a certain trend, but which show absolutely no signs of biodegradation? Is this a result of paleosterilization, or are we actually seeing migration in action here filling reservoirs containing degraded oil with a fresh charge of non-degraded oils who fingerprints completely dominate the chromatograms? To the small independent operator this may seem like an academic exercise with no direct application to production and profits. However, what if the depleted reservoir was being replenished with non-degraded oil and it was actually taking place in real time? There are many implications for production in that scenario.

In brief, this paper will present an overview of some developments in petroleum geochemistry applied to exploration problems. It is not a detailed review and it is not complex in nature to understand-it simply provides an overview of some of things geochemists can do for explorationists. It will hopefully raise the level of awareness and lead to more of the smaller independent companies incorporating some of these concepts into their exploration programs.