Drilling jar for use in a downhole network

• US 20050045339A1
• Filed: 09/02/2003
• Published: 03/03/2005
• Est. Priority Date: 09/02/2003
• Status: Active Grant

• Current Assignee: IntelliServ, LLC (NOV, Inc.)
• Original Assignee: Intelliserv, Inc. (NOV, Inc.)
• Inventors: Hall, David R., Fox, Joe
• Granted Patent: US 6,991,035 B2
• Time in Patent Office: Days
• US Class Current: 166/380
• CPC Class Codes: E21B 17/003 with electrically conducting or insulating means E21B17/028 and E21B17/023 take precedence
• CPC Class Codes: E21B 31/107 using impact means for releasing stuck parts, e.g. jars

Abstract

Apparatus and methods for integrating transmission cable into the body of selected downhole tools, such as drilling jars, having variable or changing lengths. A wired downhole-drilling tool is disclosed in one embodiment of the invention as including a housing and a mandrel insertable into the housing. A coiled cable is enclosed within the housing and has a first end connected to the housing and a second end connected to the mandrel. The coiled cable is configured to stretch and shorten in accordance with axial movement between the housing and the mandrel. A clamp is used to fix the coiled cable with respect to the housing, the mandrel, or both, to accommodate a change of tension in the coiled cable.

Claims

1. A wired downhole drilling tool comprising:

a housing;

a mandrel insertable into the housing, wherein the mandrel is axially translatable with respect to the housing;

a coiled cable, enclosed by the housing, having a first end connected to the housing and a second end connected to the mandrel, the coiled cable configured to elongate and shorten in accordance with axial movement between the housing and the mandrel;

a clamp effectively fixing the coiled cable with respect to at least one of the housing and the mandrel, to accommodate a change of tension in the coiled cable.

2. The wired downhole drilling tool of claim 1, wherein the coiled cable comprises a transmission cable enclosed within a conduit.

3. The wired downhole drilling tool of claim 2, wherein the conduit is constructed of a resilient material.

4. The wired downhole drilling tool of claim 3, wherein at least a portion of the conduit is formed into a spring-like coil.

5. The wired downhole drilling tool of claim 4, wherein the spring-like coil is in compression within the housing.

6. The wired downhole drilling tool of claim 1, wherein the clamp increases its grip on the coiled cable in response to an increase in tension therein.

7. The wired downhole drilling tool of claim 1, wherein the clamp can resist at least 10 pounds of tension in the coiled cable.

8. The wired downhole drilling tool of claim 1, wherein the coiled cable comprises a first substantially straight portion, a coiled portion, and a second substantially straight portion.

9. The wired downhole drilling tool of claim 8, wherein the clamp contacts the coiled cable proximate at least one of the junction between the first straight portion and the coiled portion, and the junction between the second straight portion and the coiled portion.

10. The wired downhole drilling tool of claim 8, wherein at least one of the first straight portion and the second straight portion is tensioned greater than the coiled portion.

11. The wired downhole drilling tool of claim 8, wherein the first straight portion, the coiled portion, and the second straight portion are formed from a single continuous cable.

12. A method for wiring a downhole drilling tool having a housing and a mandrel insertable into the housing, wherein the mandrel is axially translatable with respect to the housing, the method comprising:

connecting a first end of a coiled cable to the mandrel;

connecting a second end of the coiled cable to the housing, the coiled cable configured to elongate and shorten in accordance with axial movement between the housing and the mandrel;

fixing the coiled cable with respect to at least one of the housing and the mandrel, to accommodate a change of tension in the coiled cable.

13. The method of claim 12, wherein the coiled cable comprises a transmission cable enclosed within a conduit.

14. The method of claim 13, wherein the conduit is constructed of a resilient material.

15. The method of claim 14, wherein at least a portion of the conduit is formed into a spring-like coil.

16. The method of claim 15, wherein the spring-like coil is in compression within the housing.

17. The method of claim 12, wherein fixing further comprises increasing the grip on the coiled cable in response to an increase in tension therein.

18. The method of claim 12, wherein fixing further comprises resisting at least 10 pounds of tension in the coiled cable.

19. The method of claim 12, wherein the coiled cable comprises a first substantially straight portion, a coiled portion, and a second substantially straight portion.

20. The method of claim 19, wherein fixing further comprises fixing the coiled cable proximate at least one of the junction between the first straight portion and the coiled portion, and the junction between the second straight portion and the coiled portion.

21. The method of claim 19, further comprising tensioning at least one of the first straight portion and the second straight portion greater than the coiled portion.

22. The method of claim 19, further comprising forming the first straight portion, the coiled portion, and the second straight portion from a single continuous cable.

23. The method of claim 12, wherein fixing further comprises at least one of welding and gluing the coiled cable with respect to at least one of the housing and the mandrel, to absorb a change of tension in the cable.

24. A wired downhole drilling tool comprising:

a housing;

a mandrel insertable into the housing, wherein the mandrel is axially translatable but rotationally fixed with respect to the housing;

a cable coiled around the mandrel and enclosed by the housing;

a clamp effectively fixing the cable with respect to at least one of the housing and the mandrel, to accommodate a change of tension in the cable.