Novel Applications of Light Hydrocarbons Chemistry in Petroleum Exploration

MANGO, FRANK D., Shell Development Company, Houston, TX

The light hydrocarbons in petroleum are products of a kerogen-specific catalytic process. The catalysts are believed to be the transition metals entrained in kerogen. The process is controlled by the metals in the active sites and the kerogenous organic structures surrounding the active sites. Different catalytic sites are suggested to yield distinct distributions of light hydrocarbons. We recognize three dominant (primary) distributions, with all other distributions adequately represented by some linear combination of the three primary distributions. Three catalytic sites, therefore, can be associated with the generation of light hydrocarbons.

I introduce here a simple and inexpensive procedure using cross plots of various product ratios to correlate oils and source rocks. It has proven to be a remarkably articulate and powerful tool for deconvoluting diverse oils into genetic groups. The light hydrocarbons are also indicators of oil-generation temperature and other physical parameters associated with oil generation. The analysis of light hydrocarbons from this perspective is new. It provides the exploration geochemist with a novel technique for gaining insight into the fundamental chemistry of petroleum generation.

AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)