Discussions on the design of deepwater risers for offshore oil and gas field development

摘要

This paper erviews latest researches concerning the deepwater risers development.Offshore oil and gas development is moving into deepwaters and target water depth is becoming deeper year by year and the target at present moment is 2,000m for production and 3,000m for drilling.Innovative riser designs have been proposed and implemented.Steel catenary riser and its derivatives are typical innovations.Japan also has some research projects concerning the key technology development in this field.JAMSTEC is constructing a deepwater drillship for scientific ocean drilling program.Target water depth is 4,000m or more and design and design philosophy are studied.One of other activities is development of Compliant Vertical Access Riser led hy JNOC.CVAR utilizes catenary configuration and it can be used for production by FPSO.Technological challenges in deepwater riser development are handling of elastic response and utilization of reduced stiffness.Fatigue and collision are most important topics of deepwater risers.Development of analysis methodology of elastic response is reviewed.For drilling risers,analysis of dynamic behavior and its consideration in the design are key issues and latest research results are briefly introduced.