Downhole adjustable stabilizer

A downhole adjustable stabilizer for use in a well bore and along a drill string having a bit at the lower end thereof, the drill string having an interior flow path for passing pressurized fluid through the stabilizer, the stabilizer comprising:

• a stabilizer body having an interior passage for fluid communication with the drill string interior flow path, the stabilizer body including an upper end for interconnection with an upper portion of the drill string, a lower end for interconnection to a lower portion of the drill string, and an intermediate portion including a plurality of cavities circumferentially spaced about the stabilizer body, each cavity defined at least in part by stabilizer body sidewalls;
• a plurality of stabilizer blades each received within a respective cavity in the stabilizer body, each stabilizer blade being radially movable with respect to the stabilizer body from a retracted position to an expanded position;
• a plurality of radially movable pistons each positioned inwardly of a corresponding stabilizer blade, each piston being radially movable from an inward position to an outward position in response to pressure differential between the interior flow path within the stabilizer body and the well bore exterior of the stabilizer, the radial movement of each of the plurality of pistons mechanically effecting the radial movement of the corresponding stabilizer blade;
• and
• a locking sleeve axially movable within the stabilizer body from an unlocked position to a locked and retracted position, the locking sleeve having a central flow path for transmitting pressurized fluid through the stabilizer body, the locking sleeve being in sealed engagement with the stabilizer body, each of the plurality of radially movable pistons being carried on the locking sleeve and being in sealed engagement with the locking sleeve, the axial movement of the locking sleeve to its locked and retracted position limiting the radial outward movement of at least one of the plurality of pistons, thereby maintaining the corresponding stabilizer blade in its retracted position.

A downhole adjustable stabilizer for use in a well bore and along a drill string having a bit at the lower end thereof, the drill string having an interior flow path for passing pressurized fluid through the stabilizer and to the bit, the stabilizer comprising:

• a stabilizer body having an interior passage for fluid communication with the drill string interior flow path, the stabilizer body including an upper end for interconnection with an upper portion of the drill string, a lower end for interconnection to a lower portion of the drill string between the stabilizer and the bit, and an intermediate portion including one or more cavities spaced about the stabilizer body, each cavity defined at least in part by stabilizer body sidewalls;
• one or more stabilizer blades each received within a respective cavity in the stabilizer body, each stabilizer blade being radially movable with respect to the stabilizer body from a retracted position to an expanded position;
• one or more radially movable pistons each positioned inwardly of a corresponding one of the one or more stabilizer blades, each piston being radially movable from an inward position to an outward position in response to pressure differential between the interior flow path within the stabilizer body and the well bore exterior of the stabilizer, the radial movement of the one or more pistons functionally controlling the radial movement of the corresponding stabilizer blade;
• a locking sleeve including at least one sleeve interlocking member and movable within the stabilizer body from an unlocked position to a locked and retracted position and from its unlocked position to a locked and expanded position, the locking member being in sealed engagement with the stabilizer body, and the one or more radially movable pistons being in sealed engagement with the locking sleeve;
• one or more radially movable force transmitters each positioned radially between the one or more pistons and the corresponding stabilizer blade for transmitting a radial outward force from the one or more pistons to the corresponding stabilizer blade, each force transmitter including at least one transmitter interlocking member for engagement with the sleeve interlocking member;
• the transmitter interlocking member and the sleeve interlocking member engaging to mechanically prevent radially outward movement of the corresponding force transmitter when the locking sleeve is in its locked and retracted position;
• and
• the transmitter interlocking member and the sleeve interlocking member engaging to mechanically prevent radially inward movement of the corresponding force transmitter when the locking sleeve is in its locked and expanded position.