Patent ID: 7779919
Filing Date: 2010-08-24
Classification: E21B

Abstract:
1. A system for use in a wellbore, comprising: a string having a housing comprising a valve in which the valve comprises a valve seat having an inner channel and at least one flapper configured to pivot relative to the valve seat; wherein the at least one flapper is configured to move between a first open position and a second position in which the inner channel is obstructed; a valve actuating device for selectively opening the valve, comprising a first hydraulic device and a first contact member to urge the flapper towards the first open position; and a retention device having a second contact member to retain the at least one flapper in the first open position after the first contact member has urged the flapper towards the first open position, the retention device comprising a second hydraulic device to move the second contact member into contact with the flapper.