Patent ID: 6732819
Filing Date: 2004-05-11
Classification: E21B

Abstract:
A mudsaver valve with retrievable inner sleeve, comprising:a housing having an axis and a inner sidewall defining an interior bore; an inner sleeve disposed within the interior bore of the housing, the inner sleeve having a first end, a second end, a central passage extending between the first end and the second end, at least one inlet passage into the central passage at the first end and at least one radial outlet passage from the central passage at the second end; an annular flow control sleeve positioned between the inner sidewall of the housing and the second end of the inner sleeve; an annular piston positioned between the inner sidewall of the housing and the first end of the inner sleeve, the annular piston being axially movable relative to the housing, the annular piston being secured to the first end of the inner sleeve such that movement of the annular piston results in movement of the inner sleeve relative to the annular flow control sleeve between a valve closed position and a valve open position, in the valve closed position the at least one radial outlet passage of the inner sleeve being blocked by the annular flow control sleeve, in the valve open position the inner sleeve is moved relative to the annular flow control sleeve so that the at least one radial outlet passage is no longer blocked; and a biasing spring biases the annular piston to maintain the inner sleeve in the valve closed position, such that the inner sleeve is maintained in the valve closed position until pump pressure acting upon the inner sleeve and the annular piston overcomes the biasing force of the biasing spring causing the inner sleeve and annular piston to move to the valve open position, when pump pressure ceases the biasing spring acts upon the annular piston which carries the inner sleeve back to the valve closed position.