Technology in deep ocean drilling

Abstract

This paper principally discusses deep-water drilling technology for hydrocarbon exploration, employing floating vessels and marine risers (connecting the seabed to the surface). This is a more exacting technology than is required for riserless drilling for sub-seabed sampling, such as used by the Glomar Challenger . A floating drilling unit is subject to six degrees of freedom and offhole translation. The corresponding impact upon drilling systems is examined, as well as the risk of unplanned offhole excursions, which requires the provision of vital well pressure containing systems at seabed level. Factors involved in well design are considered, including the effect of the seawater column above the seabed in reducing subsea rock strength. The paper emphasizes the importance of personnel, environmental data, and logistics to safe, pollution-free efficient drilling, and considers future costs and technology.