Storing of extreme wellbore production pressure levels for subsequent use in hydraulic valve actuation

摘要

A downhole production flow control valve is actuated by a hydraulic source which is fed by relative high pressure and low pressure chambers or accumulators. The chambers each feed to a respective side of a piston and cylinder device which controls the valve. The pressure within the high pressure chamber is set at the highest extreme of the production fluid pressure which charges the chamber via a check valve. The pressure within the low pressure chamber is set at the lowest extreme of the production fluid pressure charged via another check valve. The pressure reserves will be replenished whenever there are pressure surges or dips providing a pressure differential, this allows the repeated operation of the valve. Embodiments are provided where valve actuation is triggered relative to a single low pressure reservoir (figure 5) and a single high pressure reservoir (figure 4).