Downhole valve

摘要

A tool that is usable with a well includes a valve element, a mechanical operator, a pressure chamber and a regulator. The valve element has a first state and a second state. The mechanical operator responds to a predetermined signature in an annulus pressure relative to a baseline level of the annulus pressure to transition the valve element from the first state to the second state. The pressure chamber exerts a chamber pressure to bias the mechanical operator to transition from the second state to the first state. The baseline level is capable of varying over time, and the regulator regulates the chamber pressure based on the baseline level.

主权项

1. A tool usable with a well, comprising:
a valve element having a first state and a second state; a first mechanical operator, comprising a piston having a first face and a second face; a pilot valve to control communication of an annulus pressure to the first mechanical operator; and a second mechanical operator to respond to annulus pressure to control operation of the pilot valve, wherein the second mechanical operator is adapted to cause pilot valve to communicate the annulus pressure to the first face of the first mechanical operator to cause the first mechanical operator to transition the valve element from the first state to the second state in response to the annulus pressure exhibiting a predetermined signature, and communicate the annulus pressure to the second face of the first mechanical operator and block communication of the annulus pressure to the first faceoff the first mechanical operator to cause the first mechanical operator to transition the valve element from the second state to the first state, wherein annulus pressure is continuously applied to the second face of the first mechanical operator.