Short section insulation assembly for well drilling string

Abstract

The invention belongs to the technical field of drilling while drilling electromagnetic transmission, and provides a short section insulation assembly for a drilling string, which comprises a first short section and a second short section, the first short section and the second short section are rigid pipes, the first short section comprises a first threaded end and a first connecting end, and the second short section comprises a second threaded end and a second connecting end. The first connecting end and the second connecting end are connected with an upper drill column and a lower drill column respectively, the first threaded end and the second threaded end can be connected with each other, the first threaded end is coated with an insulating material, and elastic non-conductive fibers are wound on the insulating material; it is guaranteed that the short section part of the drill column can bear high-strength operation pressure, bending, torsion and other loads, circulation of drilling fluid in the drill column is achieved on the premise that the structural requirement is not changed, the insulation performance of the two ends of the drill column is guaranteed, and electric conduction between the two ends of the drill column is efficiently prevented.

Description

Technical Field

[0001] The invention belongs to the technical field of electromagnetic transmission while drilling, and relates to an insulating short section in a drill string, in particular to an insulating short section assembly for a drilling drill string. Background Art

[0002] Electromagnetic transmission technology is one of the signal transmission technologies for measurement while drilling in drilling projects. Compared with the traditional mud pulse transmission technology, electromagnetic transmission technology is more efficient in gas drilling, atomization drilling, foam drilling fluid drilling and other operations.

[0003] For an electromagnetic transmission system, an insulating short section is added to the drill string. The insulation operation of the insulating short section is used to treat the upper and lower parts of the insulation as the two poles of the dipole in the electromagnetic transmission system, thereby generating low-frequency electromagnetic waves underground and transmitting them to the ground. The reason for choosing low-frequency electromagnetic waves here is that when low-frequency electromagnetic waves propagate over a long distance in the formation, the signal attenuation is relatively slow.

[0004] In order to withstand the pressure, bending, torsion and other loads generated during drilling operations, most components in the drill string are made of high-strength and high-ductility metal alloy materials. At the same time, since the insulating materials used in the short sections often have relatively low strength and ductility, how to achieve the insulation requirements between the short sections while having high strength to withstand various loads has become an urgent problem to be solved. Summary of the invention

[0005] The purpose of the present invention is to provide a short-joint insulating assembly for a drilling drill string, which ensures sufficient insulation performance without affecting the load capacity of the drill string.

[0006] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: A short section insulation assembly for a drilling drill string includes a first short section and a second short section, both of which are rigid tubes, the first short section includes a first threaded end and a first connecting end, the second short section includes a second threaded end and a second connecting end, the first connecting end and the second connecting end are respectively connected to an upper and lower drill string, the first threaded end and the second threaded end can be connected to each other, the first threaded end is coated with an insulating material, and the insulating material is wound with elastic non-conductive fibers; Furthermore, the insulating material is a ceramic material with a thickness of 0.15-0.20 mm.

[0007] Furthermore, the first short section and the second short section are both made of non-magnetic materials.

[0008] Furthermore, the elastic non-conductive fiber has a thickness of 0.1 mm.

[0009] Furthermore, both sides of the elastic non-conductive fiber are coated with anaerobic adhesive.

[0010] Furthermore, the tubular cavity portion of the second short section includes a conical portion and an annular portion, the conical portion is the second threaded end, the annular portion is adjacent to the conical portion, the annular portion is provided with an insulating ring, the insulating ring is concentric with the annular portion, and the insulating ring is made of insulating plastic material.

[0011] Furthermore, an annular groove is processed on the upper surface of the insulating ring, an O-ring is arranged in the annular groove, and the annular groove and the O-ring are concentric with the insulating ring.

[0012] Furthermore, an insulating isolation ring is provided between the tail edge of the first thread end and the opening edge of the second thread end, and the insulating isolation ring is made of ceramic material.

[0013] The beneficial effects of the present invention are: The short section insulation assembly ensures that the short section of the drill string can withstand high-intensity operating pressure, bending, torsion and other loads, while achieving the circulation of drilling fluid in the drill string and ensuring the insulation performance of both ends of the drill string without changing the structural requirements, and effectively preventing conductivity between the two ends of the drill string. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structural decomposition of the present invention; Figure 2 is a side view of the present invention; Figure 3 yes Figure 2 Analytical anatomical view of the midline A cut; Figure 4 yes Figure 3 A partial enlarged view of the middle circle B; Figure 5 is a diagram showing the connection state of the first short section and the second short section in the present invention; Figure 6 yes Figure 5 A cross-sectional view taken along line C; Figure 7 yes Figure 6 A partial enlarged view of the middle circle D; Figure 8 It is a schematic diagram of the flow direction of the drilling fluid through the first short section and the second short section in the present invention; In the figure, 1 is the first short section; 11 is the first threaded end; 12 is the first connecting end; 2 is the second short section; 21 is the second threaded end; 22 is the second connecting end; 23 is the tubular cavity part; 231 is the tapered part; 232 is the annular part; 24 is the opening end; 3 is the insulating material; 4 is the elastic non-conductive fiber; 5 is the hard insulating ring; 6 is the O-ring; 7 is the annular groove; 8 is the opening edge; 9 is the tail edge; 10 is the insulating isolation ring. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0016] like Figures 1 to 8 As shown, a drilling drill string short section insulation assembly includes a first short section 1 and a second short section 2, both of which are rigid tubes, the first short section 1 includes a first threaded end 11 and a first connecting end 12, the second short section 2 includes a second threaded end 21 and a second connecting end 22, the first connecting end 12 and the second connecting end 22 are respectively connected to the upper and lower drill strings, the first threaded end 11 and the second threaded end 21 can be connected to each other, the first threaded end 11 is coated with an insulating material 3, the insulating material 3 blocks the current from flowing between the first threaded end 11 and the second threaded end 21, and the insulating material 3 is wrapped with an elastic non-conductive fiber 4, the elastic non-conductive fiber 4 serves as an additional insulator, and also prevents the current from being conducted between the two short sections.

[0017] Among them, the insulating material 3 can be made of ceramic material with a thickness set to 0.15-0.20mm; the first short section 1 and the second short section 2 are both made of non-magnetic material; the elastic non-conductive fiber 4 is 0.1mm thick; at the same time, anaerobic glue is coated on both sides of the elastic non-conductive fiber 4, so that the elastic non-conductive fiber 4 can be more firmly adhered between the first thread end 11 and the second thread end 21.

[0018] The tubular cavity part 23 of the second short section 2 includes a conical part 231 and an annular part 232. The conical part 231 is the second threaded end. The annular part 232 is adjacent to the conical part 231. The annular part 232 is provided with a hard insulating ring 5. The hard insulating ring 5 is concentric with the annular part 232. The hard insulating ring 5 is made of insulating plastic material. An annular groove 7 is processed on the upper surface of the hard insulating ring 5. An O-ring 6 is arranged in the annular groove 7. The annular groove 7 and the O-ring 6 are both concentric with the hard insulating ring 5. The annular groove 7 serves as the base of the O-ring 6. The O-ring 6 is located in the annular groove 7. The O-ring 6 is located between the first threaded end 11 between the first short section 1 and the second short section 2 and the hard insulating ring 5, which can prevent the drilling fluid from leaking from the connection between the first threaded end 11 and the second threaded end 21.

[0019] An insulating isolation ring 10 is also arranged between the opening edge 8 of the second threaded end 21 and the tail edge 9 of the first threaded end 11. The opening edge 8 of the second threaded end 21 supports the insulating isolation ring 10. The tail edge 9 of the first threaded end 11 surrounds the opening end 24 of the second threaded end 21 and can be connected to the opening edge 8 of the second threaded end 21 of the second short section 2 as a whole. The insulating isolation ring 10 is made of a non-conductive ceramic material and is placed between the opening edge 8 and the tail edge 9. The insulating isolation ring 10 can further isolate the current between the first short section 1 and the second short section 2.

[0020] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A short section insulation assembly for a drilling drill string, characterized in that: The invention comprises a first short section and a second short section, both of which are rigid tubes, the first short section comprises a first threaded end and a first connecting end, the second short section comprises a second threaded end and a second connecting end, the first connecting end and the second connecting end are respectively connected to an upper and lower drill string, the first threaded end and the second threaded end can be connected to each other, the first threaded end is coated with an insulating material, and the insulating material is wound with elastic non-conductive fibers.

2. The short section insulation assembly for a drilling drill string according to claim 1, characterized in that: The first short section and the second short section are both made of non-magnetic materials.

3. The short-joint insulation assembly for a drilling drill string according to claim 1, characterized in that: The insulating material is a ceramic material with a thickness of 0.15-0.20 mm.

4. The short-joint insulation assembly for a drilling drill string according to claim 1, characterized in that: The elastic non-conductive fiber has a thickness of 0.1 mm.

5. The short-joint insulation assembly for a drilling drill string according to claim 1, characterized in that: The elastic non-conductive fiber is coated with anaerobic adhesive on both sides.

6. The short-joint insulation assembly for a drilling drill string according to claim 1, characterized in that: The tubular cavity part of the second short section includes a conical part and an annular part, the conical part is the second threaded end, the annular part is adjacent to the conical part, the annular part is provided with an insulating ring, the insulating ring is concentric with the annular part, and the insulating ring is made of insulating plastic material.

7. The short-joint insulation assembly for a drilling drill string according to claim 6, characterized in that: An annular groove is processed on the upper surface of the insulating ring, an O-ring is arranged in the annular groove, and the annular groove and the O-ring are both concentric with the insulating ring.

8. The short-joint insulation assembly for a drilling drill string according to claim 1, characterized in that: An insulating isolation ring is arranged between the tail edge of the first thread end and the opening edge of the second thread end, and the insulating isolation ring is made of ceramic material.

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