Patent ID: 6109351
Filing Date: 2000-08-29
Classification: E21B

Abstract:
A control system for a downhole valve to place a valve member assembly mounted therein in an open and closed position, comprising:an assembly of an actuating piston mounted in a housing with at least one seal, said assembly is operably connected to the valve member assemblysaid actuating piston having a first end in said housing in fluid communication to a pressure source;a primary pressure reservoir in communication with a second end of said actuating piston in said housing such that pressure in said primary pressure reservoir acts against existing hydrostatic pressure on said first end of said actuating piston and applied pressure from said pressure source;a pressure-equalizing mechanism in fluid communication with said pressure source and said second end of said actuating piston, said pressure-equalizing mechanism remaining in a closed position during shifting of said actuating piston with pressure applied or removed from said pressure source;said pressure-equalizing mechanism shifting to an open position upon failure of said at least one seal on said actuating piston.