DOWNHOLE SUB WITH HYDRAULICALLY ACTUABLE SLEEVE VALVE

摘要

A method for opening a port through the wall of a ported sub including: providing a sub with a port through its tubular side wall; providing a hydraulically actuable valve to cover the port, the valve being actuable to move away from a position covering the port to thereby open the port; increasing pressure within the sub to create a pressure differential across the valve to move the valve toward the low pressure side, while the port remains closed by the valve; thereafter, reducing pressure within the sub to reduce the pressure differential; and driving the valve to move it away from a position covering the port.

主权项

1. A hydraulically actuable sleeve valve comprising:
a tubular segment including a wall defining therein an inner bore; a port through the wall of the tubular segment; a sleeve supported by the tubular segment and installed to be axially moveable relative to the tubular segment from a first position covering the port to a second position and to a third position away from a covering position over the port, the sleeve including a first piston face open to tubing pressure and a second piston face open to annular pressure, such that a pressure differential can be set up between the first piston face and the second piston face to drive the sleeve toward a low pressure side from the first position into the second position with the sleeve continuing to cover the port; and a driver to move the sleeve from the second position into the third position, the driver being unable to move the sleeve until the pressure differential is substantially dissipated.