Downhole actuation method and apparatus for operating remote well control device

Abstract

A method for repeatably providing large operating forces to actuate a remote device in a well which includes well production means penetrating to some depth, surface means for restricting or closing-off flow of product from the well and changing well pressure during an operating sequence of the well, at least one downhole pressure storage chamber, a valve communicating between the pressure storage chamber and prevailing well pressure, a piston/cylinder device coupled with the remote device to actuate the latter, and isolation valve for controlling the supply of pressure energy from the storage chamber to the piston/cylinder device. The method includes the steps of replenishably storing pressure in the storage chamber during the operating sequence, such stored pressure being derived from fluid flow permitted by the valve, and repeatably operating the isolation valve to apply differential pressure to the piston/cylinder device to actuate the remote device.