Patent ID: 9657553
Date: 2017-05-23
CPC Classifications: E21B,F04B,Y10T

Claim:
1. A subsea system for uptake and supply of a liquid from and to at least one mechanical devices, the system comprising: a storage tank arranged for being filled with the liquid and having at least one outlet, the at least one outlet being in fluid communication with a lower internal volume of the storage tank, a valve assembly being arranged on a feed line, a pump having a high-pressure side and a low-pressure side and configured to supply the liquid from the storage tank to the subsea system, and a return line being connected to the high-pressure side of the pump, the valve assembly, the low-pressure side of the pump and the feed line being in fluid communication with the at least one outlet, wherein a closed, liquid-free volume is defined in an upper portion of the storage tank above a liquid volume surface of the storage tank, the feed line is connected to the low-pressure side of the pump and to at least one of the at least one outlet, such that the pump may withdraw liquid from the storage tank when the valve assembly on the feed line is closed, thereby reducing the pressure in the liquid-free volume to a level substantially below ambient liquid pressure, the opening of the valve assembly allowing liquid to flow from the at least one mechanical device to the storage tank, wherein the at least one mechanical device is subjected to a pressure difference between ambient water and the liquid-free volume and accordingly starts generating hydraulic power.