Apparatus and method for setting a downhole anchor and related telescopic joint

1. A lock ring for use as a one way movement restrictor between two telescopingly arranged tubulars to permit movement in one direction and prevent movement in the other direction of one tubular relative to the other tubular, the lock ring comprising:

a lock ring section having: a profile having one or more formations formed on an outer circumference; and one or more teeth formed on an inner circumference;

an annular section; and

a spring section located axially between the lock ring section and the annular section,

wherein the lock ring defines a plurality of circumferentially equi-spaced tongues, each tongue extending from the annular section and each tongue defining a portion of the lock ring section and a portion of the spring section, and

wherein each tongue defines an S-shaped spring.

2. The lock ring as claimed in claim 1 , wherein each tongue has a part circular extent.

3. The lock ring as claimed in claim 1 , wherein the annular section comprises a screw threaded section for fixing the lock ring to an outer one of the tubulars.

4. The lock ring as claimed in claim 1 , wherein the lock ring is unitary.

5. The lock ring as claimed in claim 1 , wherein the lock ring section and the spring section are axially non-overlapping.

6. A lock ring for use as a one way movement restrictor between first and second telescopingly arranged tubulars to permit movement in one direction and prevent movement in the other direction of one of the first and second tubulars relative to the other of the first and second tubulars, the lock ring comprising:

a lock ring section having: a profile having one or more formations formed on one of an outer or inner circumference of the lock ring; and one or more teeth formed on the other of the outer or inner circumference of the lock ring;

an annular section; and

a spring section located axially between the lock ring section and the annular section,

wherein the lock ring defines a plurality of circumferentially equi-spaced tongues, each tongue extending from the annular section and each tongue defining a portion of the lock ring section and a portion of the spring section, and

wherein each tongue defines an S-shaped spring.

7. The lock ring as claimed in claim 6 , wherein each tongue has a part circular extent.

8. The lock ring as claimed in claim 6 , wherein the annular section comprises a screw threaded section for fixing the lock ring to one of the first and second tubulars.

9. The lock ring as claimed in claim 6 , wherein the lock ring is unitary.

10. The lock ring as claimed in claim 6 , wherein the lock ring section and the spring section are axially non-overlapping.

11. A unitary lock ring for use as a one way movement restrictor between two telescopingly arranged tubulars to permit movement in one direction and prevent movement in the other direction of one tubular relative to the other tubular, the lock ring comprising:

a lock ring section having: a profile having one or more formations formed on an outer circumference of the lock ring; and one or more teeth formed on an inner circumference of the lock ring;

wherein each formation of the profile formed on the outer circumference of the lock ring comprises a flank face defining an acute flank angle relative to a longitudinal direction and a rear face which defines an acute cut back angle relative to the longitudinal direction;

an annular section; and

a spring section located axially between the lock ring section and the annular section,

wherein the spring section is configured to urge the lock ring section and the annular section axially apart when the spring section is subjected to axial compression and the spring section is configured to urge the lock ring section and the annular section axially together when the spring section is subjected to axial tension; and

wherein the annular section comprises a screw thread formation thereon.

12. The lock ring as claimed in claim 11 , wherein each flank face defines a flank angle in the region of 20 degrees relative to the longitudinal direction and each rear face defines a cut back angle in the region of 80 degrees relative to the longitudinal direction.

13. The lock ring as claimed in claim 11 , wherein the lock ring defines a plurality of circumferentially equi-spaced tongues, each tongue extending from the annular section and each tongue defining a portion of the lock ring section and a portion of the spring section.

14. A unitary lock ring for use as a one way movement restrictor between first and second telescopingly arranged tubulars to permit movement in one direction and prevent movement in the other direction of one of the first and second tubulars relative to the other of the first and second tubulars, the lock ring comprising:

a lock ring section having: a profile having one or more formations formed on one of an outer or an inner circumference of the lock ring; and one or more teeth formed on the other of the outer or inner circumference of the lock ring;

wherein each formation of the profile comprises a flank face defining an acute flank angle relative to a longitudinal direction and a rear face which defines an acute cut back angle relative to the longitudinal direction;

an annular section; and

a spring section located axially between the lock ring section and the annular section,

wherein the spring section is configured to urge the lock ring section and the annular section axially apart when the spring section is subjected to axial compression and the spring section is configured to urge the lock ring section and the annular section axially together when the spring section is subjected to axial tension; and

wherein the annular section comprises a screw thread formation thereon.

15. The lock ring as claimed in claim 14 , wherein the annular section comprises a screw thread formation thereon.

16. The lock ring as claimed in claim 14 , wherein the lock ring defines a plurality of circumferentially equi-spaced tongues, each tongue extending from the annular section and each tongue defining a portion of the lock ring section and a portion of the spring section.

17. A lock ring assembly comprising:

an inner tubular and an outer tubular, the inner and outer tubulars being telescopingly arranged; and

a unitary lock ring comprising:

a lock ring section having: a profile having one or more formations formed on an outer circumference of the lock ring for engagement with a suitable profile formed on an inner circumference of the outer tubular; and one or more teeth formed on an inner circumference of the lock ring, the teeth being adapted to dig into an outer surface of the inner tubular;

an annular section; and

a spring section located axially between the lock ring section and the annular section,

wherein the lock ring defines a plurality of circumferentially equi-spaced tongues, each tongue extending from the annular section and each tongue defining a portion of the lock ring section and a portion of the spring section,

such that the profile having one or more formations on the outer circumference of the lock ring section of the lock ring and/or the said one or more teeth on the inner circumference of the lock ring section of the lock ring permits the lock ring to be pushed along the outer surface of the inner telescopic tubular when pushed by the outer telescopic tubular in one direction; and

is further adapted to dig the teeth into the outer surface of the inner telescopic tubular when the push in said one direction is removed or when it is pushed by the outer telescopic tubular in the other direction in order to prevent the lock ring from moving in the other direction relative to the inner telescopic tubular, and

wherein the spring section of the lock ring biases the lock ring in the said one direction.

18. The lock ring assembly as claimed in claim 17 , wherein the annular section comprises a screw thread formation thereon to provide for fixing of the lock ring to the outer tubular.

19. A lock ring assembly comprising:

a first tubular and a second tubular, the first and second tubulars being telescopingly arranged; and

a unitary lock ring comprising:

a lock ring section having: a profile having one or more formations formed on one of an outer or inner circumference of the lock ring; and one or more teeth formed on the other of the outer or inner circumference of the lock ring; an annular section; and a spring section located axially between the lock ring section and the annular section,

wherein the lock ring defines a plurality of circumferentially equi-spaced tongues, each tongue extending from the annular section and each tongue defining a portion of the lock ring section and a portion of the spring section, and

such that the profile having the one or more formations formed on one of the outer or inner circumference of the lock ring and/or the said one or more teeth formed on the other of the outer or inner circumference of the lock ring permits the lock ring to be pushed along a surface of one of the first and second tubulars when pushed by the other of the first and second tubulars in one direction; and

is further adapted to dig the teeth into the surface of said one of the first and second tubulars when the push in said one direction is removed or when it is pushed by the other of the first and second tubulars in the other direction in order to prevent the lock ring from moving in the other direction relative to said one of the first and second tubulars, and

wherein the spring section of the lock ring biases the lock ring in the said one direction.