Frontiers in Organic Geochemistry: ABSTRACT

Abstract

During the past 20 years, an explosion has occurred in both the End_Page 491------------------------------ analytical sophistication of organic geochemistry and the application of organic geochemistry to better evaluating risks when making exploration decisions. Unfortunately, the applications available from present technology have not been fully exploited. Thus, a major frontier exists in the increased exploitation of presently available technology. This frontier can best be exploited by placing an experienced exploration geologist, with an interest in organic geochemistry and basin analysis, between the chemist in the lab and the exploration manager. Meanwhile, technology improves and new opportunities appear, although we will probably be dealing with incremental improvements, not the conceptual breakthroughs of the past 20 years. Anticipated developments include the following. (1) Finer tuning of the window for different types of organic matter, generation products, and rock matrices. (2) Better generation, migration, and accumulation models. Many numbers are multiplied together in these models, thereby leading to large uncertainties in the final prediction. Geochemistry will help better define such models in several ways; however, its major contribution will probably be in the increased accuracy and numbers of measurements of the actual distribution of hydrocarbons and other organic compounds in the subsurface. More such data are sorely needed to increase our ability to quantitatively evaluate migration mechanisms. Most of the oil and gas remains in the potential source rock. Better understanding of when, how, and why some of its does move is clearly an important frontier. (3) Improved prediction of source rock distribution, type, thickness, and maturity. This will be accomplished by integrating organic geochemistry with modern and paleo-oceanography, paleoclimatology, and plate tectonics. By better understanding why source rocks are where they are, we will better predict where others might exist, and conversely, where they are not to be expected. (4) Increased efforts to apply biomarker geochemistry to exploration problems. (5) More sophisticated, non-biomarker, methods for characterizing oils. These will lead to better oil-oil and oil-source correlations for use in exploration, but will also be increasingly applied to a variety of development and production problems. (6) Increased studies of interactions between organic matter, rocks, and fluids. In the past, the prime interest was in the effects of different rock matrices on organic maturation rates. Results have been disappointing, perhaps because the major effects are in the other direction. Organic matter and its decomposition products can have a major effect on rock diagenesis and sedimentary ore deposits. (7) The geochemistry of deep, hot, gas accumulations. This list is not exhaustive. Opportunities abound for the application of geochemistry to exploration problems. The technology exist, or soon will. The frontier is how well the resourcefulness of our profession will be used to apply the available technology to our problems. End_of_Article - Last_Page 492------------