ABSTRACT: A worldwide geochemical comparison of lacustrine crude oils
Schiefelbein, Craig1, Marcio Mello2 (1) Geochemical Solutions International, Inc, Houston, TX (2) Analytical Solutions, Rio de Janeiro, Brazil
Oil geochemistry is a fundamental component of regional exploration and production programs and is as important to basin analysis as an understanding of regional structural fabric, regional evolution of the structural elements and regional stratigraphic relationships. Oil geochemistry is applied here to better understand and predict the occurrence of lacustrine-derived oils around the world. This is possible since the geochemical characteristics of crude oils reveal important information on paleoenvironmental conditions of source rock deposition and possible age. This paper compares geochemical data from representative crude oils from around the world. Results suggest that lacustrine oils can be readily distinguished from marine oils and can be further separated into four broad groups, differing from each other in terms of relative maturity, type of depositional environment of the source rocks and/or possible age. In addition, variations in physical properties, isoprenoid ratios, isotopic compositions and/or biomarker distributions can often be associated with a specific source environment, such as lacustrine fresh versus lacustrine saline. Possible genetic relationships and the areal and spatial distribution of these different lacustrine oils are also discussed.
AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia