VARIABLE STIFFNESS FIXED BEND HOUSING FOR DIRECTIONAL DRILLING

• US 20170350192A1
• Filed: 12/29/2014
• Published: 12/07/2017
• Est. Priority Date: 12/29/2014
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Sadabadi, Hamid, Kirkhope, Kennedy
• Granted Patent: US 10,641,044 B2
• Time in Patent Office: Days
• CPC Class Codes: E21B 17/00 Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
• CPC Class Codes: E21B 7/062 the tool shaft rotating inside a non-rotating guide travelling with the shaft E21B7/067 and E21B7/068 take precedence
• CPC Class Codes: E21B 7/067 with means for locking sections of a pipe or of a guide for a shaft in angular relation, e.g. adjustable bent sub

Abstract

An example apparatus for controlling the direction of drilling a borehole includes an outer housing having non-uniform stiffness and an inner housing at least partially within and rotationally independent from the outer housing and having non-uniform stiffness, A drive shaft may be at least partially within the inner housing. At least one of the outer housing and the inner housing may include a tubular structure with at least one of multiple materials with different stiffness, and a portion with less structural material than another portion.

Claims

1. An apparatus for controlling the direction of drilling a borehole, comprising:

an outer housing having non-uniform stiffness;

an inner housing at least partially within and rotationally independent from the outer housing and having non-uniform stiffness; and

a drive shaft at least partially within the inner housing.

2. The apparatus of claim 1, wherein at least one of the outer housing and the inner housing comprises a tubular structure with at least one of

multiple materials with different stiffness, and

a portion with less structural material than another portion.

3. The apparatus of claim 2, wherein the portion of the tubular structure with less structural material than another portion comprises at least one axial, radial, or angular portion of the tubular structure with at least one of a notched area on a surface thereof and a series of longitudinal holes therethrough.

4. The apparatus of claim 2, wherein the multiple materials with different stiffness characteristics comprise at least one composite material positioned at an axial, radial, or angular portion of the tubular structure.

5. The apparatus of claim 2, wherein the multiple materials with different stiffness characteristics comprise at least two materials positions at different axial, radial, or angular portions of the tubular structure.

6. The apparatus of claim 1, further comprising a positioning device to rotate one of the inner housing and the outer housing with respect to the other one of the inner housing and the outer housing.

7. The apparatus of claim 6, wherein the positioning device comprises an electric motor coupled to the inner housing.

8. The apparatus of claim 6, wherein the positioning device comprises an adjusting ring coupled to the outer housing.

9. An method for controlling the direction of drilling a borehole, comprising:

drilling a borehole in a first direction in a subterranean formation;

altering a stiffness characteristic of a housing within the borehole;

drilling the borehole in a second direction in the subterranean formation, the second direction based, at least in part, on the altered stiffness characteristic of the housing.

10. The method of claim 9, wherein altering the stiffness characteristic of the housing within the borehole comprising rotating one of an inner housing having non-uniform stiffness and an outer housing having non-uniform stiffness with respect to the other one of the inner housing having non-uniform stiffness and the outer housing having non-uniform stiffness.

11. The method of claim 10, wherein at least one of the outer housing and the inner housing comprises a tubular structure with at least one of

multiple materials with different stiffness, and

a portion with less structural material than another portion.

12. The method of claim 10, wherein at least one of the outer housing and the inner housing comprises a tubular structure with at least one of

multiple materials with different stiffness, and

a portion with less structural material than another portion.

13. The method of claim 9, wherein altering the stiffness characteristic of a housing within the borehole comprises at least one of

changing a thermal condition of the housing;

altering a chemical condition of the housing; and

applying at least one of an electrical signal, a magnetic field, and an electrical field to the housing.

14. The method of claim 9, wherein

drilling the borehole in the first direction in the subterranean formation comprises applying a weight on a drill bit within the borehole and rotating the drill bit using a drive shaft at least partially disposed within the housing;

and

drilling the borehole in the second direction in the subterranean formation comprises applying the same weight on the drill bit within the borehole and rotating the drill bit using the drive shaft.

15. The method of claim 14, wherein rotating the drill bit using the drive shaft comprises rotating the drill bit uses a downhole motor coupled to the drill bit though the drive shaft.

16. An system for controlling the direction of drilling a borehole, comprising:

a variable stiffness housing;

a drive shaft at least partially within the variable stiffness housing;

a downhole motor coupled to the drive shaft and the variable stiffness housing; and

a drill bit coupled to the drive shaft.

17. The system of claim 16, wherein the variable stiffness housing comprises

an outer housing having non-uniform stiffness;

and

an inner housing at least partially within and rotationally independent from the outer housing and having non-uniform stiffness.

18. The system of claim 16, further comprising at least one of an adjusting ring coupled to the outer housing and an electric motor coupled to the inner housing.

19. The system of claim 17, wherein at least one of the outer housing and the inner housing comprises a tubular structure with at least one of

multiple materials with different stiffness, and

a portion with less structural material than another portion.

20. The system of claim 19, wherein the portion of the tubular structure with less structural material than another portion comprises at least one axial, radial, or angular portion of the tubular structure with at least one of a notched area on a surface thereof and a series of longitudinal holes therethrough.

21. The system of claim 19, wherein the multiple materials with different stiffness characteristics comprises at least one of

a composite material positioned at an axial, radial, or angular portion of the tubular structure;

multiple materials with different stiffness characteristics comprise at least two materials positions at different axial, radial, or angular portions of the tubular structure.

22. The system of claim 16, wherein the variable stiffness housing comprises at least one of a shape memory alloy, a piezoelectric material, and a piezoresistive material.