Patent ID: 9617803
Date: 2017-04-11
CPC Classifications: E21B

Claim:
1. An apparatus, comprising: a direct current (DC) power distribution bus; an energy storage system coupled to the DC power distribution bus wherein the energy storage system comprises: a power dissipater coupled to the DC power distribution bus; a drilling riser; a plurality of wires coupled to the drilling riser; a first and second electrical tensioner coupled to the drilling riser via a first and a second wire of the plurality of wires and coupled to the power distribution bus; a hydro-pneumatic tensioner coupled to the drilling riser via a third wire of the plurality of wires; and a controller configured: to transfer energy from the energy storage device to at least one of the first and second electrical tensioners; to store energy from at least one of the first and second electrical tensioners in the energy storage device; to measure tensions delivered by the hydro-pneumatic and electrical tensioners; and to determine a tension for the first and second electrical tensioners based, in part, on the measured tensions of the hydro-pneumatic and electrical tensioners.