Deepwater drilling: challenges, evolutions of drilling practice, well design and lessons for Vietnam

Abstract

This paper provides an overview of the changes in deepwater and ultra-deepwater definitions, the evolutions in drilling rigs, well design, drilling and completion practices, and equipment to overcome many unique challenges and high drilling costs. Oil and gas drilling and development in deepwater and ultra-deepwater have been around for more than 60 years and become more and more important to the global petroleum industry. With each advancement in technology, we can explore and produce hydrocarbons further offshore, at deeper water depths, and thus the definitions of deepwater and ultra deepwater have been repeatedly rewritten. This segment of the petroleum industry has experienced the highest growth and number of innovations thanks to many giant deepwater discoveries turned into productive fields in the Gulf of Mexico, Brazil, North Sea, West Africa, and elsewhere throughout the world. With more and more wells drilled at ever increasing water depth, the drilling challenges, including both natural and operations hazards increase exponentially, which result in more and more stringent technical requirements for a safe operation. These are being met by the rapid and complicated evolution of BOPs and drillships over several generations, optimization of deepwater big bore well design, and applications of drilling and completion, marine navigation, ROV technologies and procedures, and sharing of lessons learned. This demonstrates the industry's continued and focused interest in the process of enabling resources extraction from this environment of deep and ultra-deep water, especially to combat the high risks and high investment costs for deep and ultra-deep water projects, in which drilling cost is the most significant share. In the second section, the paper looks at the hydrocarbon potentials of Vietnam deepwater and ultra deepwater, the current status, and the various challenges, and proposes required steps to enable Vietnam to tap in this vast unexplored hydrocarbon resources.