Downhole release apparatus

1. An apparatus comprising:

a downhole tool comprising:

a first connector sub comprising:

a housing connectable with a first portion of a tool string; and

a first latching member, wherein the housing is movable with respect to the first latching member;

a second connector sub connectable with a second portion of the tool string, wherein the second connector sub comprises a second latching member, and wherein the first and second latching members engage thereby connecting the first and second connector subs; and

a blocking member movable with respect to the first latching member, the second latching member, and the housing, wherein movement of the housing with respect to the first latching member facilitates movement of the blocking member from a first position in which the blocking member prevents the first and second latching members from disengaging to a second position in which the blocking member permits the first and second latching members to disengage thereby permitting the first and second connector subs to disconnect.

2. The apparatus of claim 1 wherein the first latching member and the housing are connected, wherein the housing is movable upward with respect to the first latching member and the blocking member when an upward force is applied to the housing, and wherein the housing is movable downward with respect to the first latching member when the upward force is stopped from being applied to the housing to thereby cause movement of the blocking member from the first position to the second position.

3. The apparatus of claim 1 wherein the first latching member and the housing are slidably connected, and wherein upward movement of the housing with respect to the first latching member and the blocking member is prevented until a predetermined upward force is applied to the housing.

4. The apparatus of claim 3 wherein subsequent downward movement of the housing with respect to the first latching member causes movement of the blocking member from the first position to the second position.

5. The apparatus of claim 1 wherein the first latching member and the housing are fixedly connected, and wherein the housing is movable upward with respect to the first latching member and the blocking member when a predetermined upward force is applied to the housing.

6. The apparatus of claim 1 wherein the first latching member and the housing are fixedly connected via a fastener, and wherein the housing is movable upward with respect to the first latching member and the blocking member when a predetermined upward force is applied to the housing to unfasten the housing from the first latching member.

7. The apparatus of claim 6 wherein the fastener is or comprises a shear pin.

8. The apparatus of claim 1 wherein upward movement of the housing with respect to the first latching member and the blocking member and then downward movement of the housing with respect to the first latching member causes movement of the blocking member from the first position to the second position.

9. The apparatus of claim 1 wherein the housing is movable upwardly with respect to the first latching member and the blocking member and then downwardly with respect to the first latching member to cause movement of the blocking member from the first position to the second position while:

the tool string is located downhole;

the downhole tool is connected between the first and second portions of the tool string; and

the second portion of the tool string is stuck downhole.

10. The apparatus of claim 1 wherein the housing is movable upwardly with respect to the first latching member and the blocking member by applying an upward force to the housing while:

the tool string is located downhole;

the downhole tool is connected between the first and second portions of the tool string; and

the second portion of the tool string is stuck downhole.

11. The apparatus of claim 1 wherein the housing is movable upwardly with respect to the first latching member and the blocking member by applying an upward force to the housing by a jarring tool and/or by a drawworks located at a wellsite surface while:

the tool string is located downhole;

the downhole tool is connected between the first and second portions of the tool string; and

the second portion of the tool string is stuck downhole.

12. The apparatus of claim 1 wherein:

the housing comprises a first shoulder;

the blocking member comprises a second shoulder;

the housing is movable upward with respect to the first latching member and the blocking member from a position in which the first shoulder is disposed below the second shoulder to a position in which the first shoulder is disposed above the second shoulder;

the housing is then movable downward with respect to the first latching member; and

the downward movement of the housing with respect to the first latching member causes the first shoulder to contact the second shoulder thereby pushing the blocking member downward from the first position to the second position.

13. The apparatus of claim 12 wherein the blocking member comprises a biasing member configured to move the second shoulder in a lateral direction when the housing is moved upward with respect to the first latching member to the position in which the first shoulder is disposed above the second shoulder such that the first and second shoulders make contact when the housing is moved downward.

14. The apparatus of claim 1 wherein a portion of the blocking member extends from the first latching member, and wherein upward and then downward movement of the housing with respect to the first latching member causes movement of the blocking member from the first position to the second position.

15. An apparatus comprising:

a downhole tool comprising:

a first connector sub comprising:

a housing connectable with a first portion of a tool string; and

a first latching member;

a second connector sub connectable with a second portion of the tool string, wherein the second connector sub comprises a second latching member, and wherein the first and second latching members engage to connect the first and second connector subs and thus connect the first and second portions of the tool string; and

a blocking member movable with respect to the first latching member, the second latching member, and the housing, wherein upward movement of the housing with respect to the first latching member and the blocking member and then downward movement of the housing with respect to the first latching member facilitates movement of the blocking member from a first position in which the blocking member prevents the first and second latching members from disengaging to a second position in which the blocking member permits the first and second latching members to disengage thereby permitting the first and second connector subs to disconnect and thus disconnect the first and second portions of the tool string.

16. The apparatus of claim 15 wherein the upward movement of the housing with respect to the first latching member and the blocking member is prevented via a fastener until a predetermined upward force is applied to the housing to unfasten the housing from the first latching member.

17. The apparatus of claim 16 wherein the fastener is or comprises a shear pin.

18. The apparatus of claim 16 wherein the predetermined force is applied to the housing by a jarring tool and/or by a drawworks located at a wellsite surface while:

the tool string is located downhole;

the downhole tool is connected between the first and second portions of the tool string; and

the second portion of the tool string is stuck downhole.

19. The apparatus of claim 15 wherein after the housing moves upwardly with respect to the first latching member and the blocking member, the housing is movable downwardly with respect to the first latching member to cause the blocking member to move with respect to the first and second latching members from the first position to the second position.

20. The apparatus of claim 19 wherein the housing is movable upwardly and downwardly while:

the tool string is located downhole;

the downhole tool is connected between the first and second portions of the tool string; and

the second portion of the tool string is stuck downhole.

21. An apparatus comprising:

a downhole tool comprising:

a first connector sub comprising:

a housing connectable with a first portion of a tool string; and

a first latching member, wherein the housing is movable with respect to the first latching member;

a second connector sub connectable with a second portion of the tool string, wherein the second connector sub comprises a second latching member, and wherein the first and second latching members engage thereby connecting the first and second connector subs; and

a blocking member movable with respect to the first and second latching members,

wherein:

the housing is movable with respect to the first latching member to facilitate movement of the blocking member from a first position in which the blocking member prevents the first and second latching members from disengaging to a second position in which the blocking member permits the first and second latching members to disengage thereby permitting the first and second connector subs to disconnect;

the housing comprises a first shoulder;

the blocking member comprises a second shoulder;

the housing is movable upward with respect to the first latching member from a position in which the first shoulder is disposed below the second shoulder to a position in which the first shoulder is disposed above the second shoulder; and

the housing is then movable downward with respect to the first latching member to cause the first shoulder to contact the second shoulder and push the blocking member downward from the first position to the second position.