Shutting down an underwater fluid production well

摘要

A production control system for an underwater well, comprises: first electrically operated means for supplying first hydraulic fluid, for opening a first control valve of the well; second electrically operated means, for supplying second hydraulic fluid at a higher pressure than said first fluid, for opening a further control valve of the well; electronic circuitry (SEM1) for providing electrical power for operating said first and second means; and means for controlling the sequence of closing said control valves as a result of a loss of electrical power from said electronic circuitry. The controlling means comprises: electrical power storage means; detection means responsive to said loss of power from said electronic circuitry; and means coupled with said detection means for using electrical power from said storage means to keep said further control valve open for a period after closure of said first control valve and close it after said period.

主权项

1. A production control system for an underwater well, the production control system comprising:
a first electrically operated valves configured to supply first hydraulic fluid, for opening a first control valve of the well; a second electrically operated valve configured to supply second hydraulic fluid at a higher pressure than the first hydraulic fluid, for opening a further control valve of the well; electronic circuitry configured to provide electrical power for operating the first electrically operated valves and the second electrically operated valves; and a controller configured to control the sequence of closing the control valves as a result of a loss of electrical power from the electronic circuitry, the controller comprising:
an electrical power storage;a detector responsive to the loss of power from the electronic circuitry; anda central processor unit coupled with the detector, wherein the central processor unit is configured to use electrical power from the electrical power storage to keep the further control valve open for a period after closure of the first control valve and close the further control valve after the period.