Dual Active Heave Drilling Drawworks: From Concept to Operational Life

Abstract In 2010, a fit-for-purpose Mobile Offshore Drilling Unit (MODU) was equipped with a dual Active Heave Drilling Drawworks. As a concept, this layout was initially presented in the SPE/IADC paper 79826 "Dual Drawworks Provide Operational Redundancy and Reduce Cut and Clip Costs." After additional developments with the drilling contractor, the equipment provider and the vessel designer, this system went from concept to reality. Fundamentally, this system is based on having two Active Heave Drilling drawworks mounted on the port and starboard side of the derrick working simultaneously as a complete 1,000 (i.s.o. 1000) ton hoisting system. The initial goals of the system were to reduce slip and cut costs, increase tripping time and provide overall redundancy for ultra-deepwater operations. This follow-up paper will examine field performance data, provided by the drilling contractor, while looking to juxtapose the initial engineering concept with the systems capability to successfully transition dual Active Heave Drilling drawworks from concept to operational life.