Downhole deployment valves
Methods and apparatus enable reliable and improved isolation between two portions of a bore extending through a casing string disposed in a borehole. A downhole deployment valve (DDV) may provide the isolation utilizing a valve member, such as a flapper, that is disposed in a housing of the DDV and is designed to close against a seat within the housing. The DDV includes an operating mechanism for opening/closing the DDV. In use, pressure in one portion of a well that is in fluid communication with a well surface may be bled off and open at well surface while maintaining pressure in another portion of the casing string beyond the DDV.
1. A valve for use in a casing string, the valve comprising:
a valve seat body;
a valve member moveable between a first position in which the valve member is engaged with the valve seat body and a second position in which the valve member is disengaged from the valve seat body;
an actuator sleeve movable within the valve seat body between a retracted location spaced from the valve member and an extended location passing through the valve seat body to displace the valve member to the second position; and
a closure mechanism that is configured to move the valve member from the second position to the first position, the closure mechanism having a linkage member with a first end operatively connected to the valve member and a second end operatively connected to a biasing member disposed around the valve seat body,
wherein the linkage member traverses an interface between the valve seat body and the valve member.
2. The valve of claim 1 , wherein the linkage member comprises a linkage arm.
3. The valve of claim 1 , wherein the linkage member comprises a cable, the cable being configured to be attached to the valve member at a location that is opposite a pivot point of the valve member.
4. The valve of claim 3 , further comprising a cam member attached to the valve member and the cable, the cam member being configured to support the cable.
5. The valve of claim 4 , wherein the cam member is configured to move as the valve member moves between the first position and the second position.
6. The valve of claim 1 , wherein the biasing member comprises a coil spring.
7. The valve of claim 1 , wherein the biasing member has a first end and a second end, the first end being operatively connected to the linkage member and the second end being operatively connected to a base.
8. The valve of claim 7 , wherein the biasing member has a first length when the valve member is in the first position and a second length when the valve member is in the second position.
9. The valve of claim 7 , wherein the first length of the biasing member is longer than the second length of the biasing member.
10. The valve of claim 7 , wherein the biasing member is compressed against the base when the valve member is in the second position.
11. The valve of claim 7 , wherein the base may be moved from a first longitudinal position to a second longitudinal position along the valve seat body to adjust the amount of compression in the biasing member.
12. The valve of claim 7 , wherein the linkage member extends through an opening in the base.
13. A valve for use in a casing string, the valve comprising:
a valve seat body;
a valve member moveable between a first position in which the valve member is engaged with the valve seat body and a second position in which the valve member is disengaged from the valve seat body;
an actuator sleeve movable within the valve seat body between a retracted location spaced from the valve member and an extended location passing through the valve seat body to displace the valve member to the second position; and
a closure mechanism that is configured to move the valve member from the second position to the first position, the closure mechanism having a linkage member with a first end operatively connected to the valve member and a second end operatively connected to a biasing member disposed around the valve seat body,
wherein the linkage member comprises a cable, the cable being configured to be attached to the valve member at a location that is opposite a pivot point of the valve member.
14. The valve of claim 13 , further comprising a cam member attached to the valve member and the cable, the cam member being configured to support the cable.
15. The valve of claim 14 , wherein the cam member is configured to move as the valve member moves between the first position and the second position.
16. A valve for use in a casing string, the valve comprising:
a valve seat body;
a valve member moveable between a first position in which the valve member is engaged with the valve seat body and a second position in which the valve member is disengaged from the valve seat body;
an actuator sleeve movable within the valve seat body between a retracted location spaced from the valve member and an extended location passing through the valve seat body to displace the valve member to the second position; and
a closure mechanism that is configured to move the valve member from the second position to the first position, the closure mechanism having a linkage member with a first end operatively connected to the valve member and a second end operatively connected to a biasing member disposed around the valve seat body,
wherein:
the biasing member has a first end and a second end, the first end being operatively connected to the linkage member and the second end being operatively connected to a base, and
the base may be moved from a first longitudinal position to a second longitudinal position along the valve seat body to adjust the amount of compression in the biasing member.
17. A valve for use in a casing string, the valve comprising:
a valve seat body;
a valve member moveable between a first position in which the valve member is engaged with the valve seat body and a second position in which the valve member is disengaged from the valve seat body;
an actuator sleeve movable within the valve seat body between a retracted location spaced from the valve member and an extended location passing through the valve seat body to displace the valve member to the second position; and
a closure mechanism that is configured to move the valve member from the second position to the first position, the closure mechanism having a linkage member with a first end operatively connected to the valve member and a second end operatively connected to a biasing member disposed around the valve seat body,
wherein:
the biasing member has a first end and a second end, the first end being operatively connected to the linkage member and the second end being operatively connected to a base, and
the linkage member extends through an opening in the base.