--> Abstract: Assessment of Source Rock Organic Facies Using Oil Molecular Data, by M. R. Mello; #90942 (1997).

Datapages, Inc.Print this page

Abstract: Assessment of source rock organic facies using oil molecular data

MELLO, M.R

Biomarker analyses from oils allowed the assessment, identification and differentiation of source rock organic facies that can have important implications in the recognition of the exploration risk. The samples studied were recovered from Latin American sedimentary basins of Cretaceous and Tertiary ages. Three case histories involving exploration implications of regional variations in source rock organic facies are discussed: (i) Lower Neocomian deep, fresh to brackish water lacustrine systems (Camamu basin, Brazil), (ii) Tithonian semi-restricted shallow marine carbonate to siliciclastic systems (Southeastern basins, Mexico) and (iii) Upper Cretaceous to Tertiary marine semi-restricted to deltaic systems (Lower Magdalena Valley, Colombia).

Within the tectono-sedimentary settings of these basins, both successive sea level changes and expansions and contractions of the lacustrine water body, created variations in the depositional environments, including: salinity, temperature, carbonate and siliciclastic contents. Such changes control the development of water stratification and bottom water anoxia, and hence the deposition of source rocks. These differences can be identified by their individual biomarker features directly from oil samples, without the need of actual source rock data. Even when oils or depositional environments are mixed, individual components and their relative contributions can be assessed.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria