Hydrocarbon shows and source rocks in scientific ocean drilling

摘要

Scientific ocean drilling has been conducted for more than three decades. The Ocean Drilling Program (ODP) and its predecessor the Deep Sea Drilling Project (DSDP) have conducted activities with riser-less ships. These two programs have examined more than 1200 localities and recovered more than 348,073 m of core. Nearly all of this material has been obtained from areas outside known hydrocarbon-producing regions. However, limited coring has taken place within or near hydrocarbon-bearing provinces such as the Gulf of Mexico, offshore California (Santa Barbara Channel), the Northwest Shelf of Australia, and along the West African margin. Extensive predrill site reviews are performed for safety reasons and to prevent pollution. Despite these reviews, a number of minor hydrocarbon shows have been encountered, suggesting the presence of viable deepwater petroleum systems in many parts of the globe. Scientific ocean drilling has also provided access to samples of possible hydrocarbon source rocks. Such rocks are well constrained stratigraphically and free of contamination by drilling fluids. This paper is focused on how the results of these scientific drilling programs can be used as part of a hydrocarbon exploration program through an examination of "black shales" (potential source rocks), oil shows, gas occurrences, and gas hydrates. Such a study shows how a basic research program can be used as part of the global resource evaluation program. By no means is it an attempt to synthesize all organic geochemical data that have been generated by the program.