The industry is being challenged to further reduce costs to ensure the economic viability of deepwater projects. To meet this demand, flywheel technology recovers energy during active heave compensation, tripping, and all block movement and the excess energy is transferred back into the drilling system reducing the amount of fuel consumed as well as operating expenses.
This paper details the new approach to rig power systems, the kinetic energy recovery system and its benefits: operating cost savings through reduced energy consumption and maintenance expense, reduced emissions, and improved operation reliability and safety.
During heave compensation, tripping, and all block movement, AC drawworks (DW) motors generate electricity when slowing and stopping the load. During the entire downward half-wave, the supply will be zero since all the kinetic energy is dissipated in the conventional braking resistor.
With this system excessive energy is regenerated, converted into kinetic energy through the flywheel and the kinetic energy is reapplied to rig operations. This smooths out peak power demands, levels the load on generators and provides a back-up power source to get the bit off bottom in the event of a blackout.
The ratio between peak power consumption with and without the flywheel is 1:10 for a given winch with a certain efficiency. The ratio between average power consumption with and without the flywheel is 1:2,5.
This paper will also look at field test data quantifying energy and cost savings.