Titanium alloy drill rod joint and manufacturing method thereof

Abstract

The invention discloses a titanium alloy drill pipe joint and a manufacturing method thereof. The wear-resistant belt comprises a wear-resistant belt covering the surface thereof, wherein the wear-resistant belt comprises an intermediate medium layer and wear-resistant steel, wherein the intermediate medium layer is used to prevent the titanium alloy drill pipe joint and the wear-resistant steel from breaking, wherein the intermediate medium layer is connected to the wear-resistant steel in a composite manner, wherein the thickness of the intermediate medium layer is 1.5 mm, the thickness of the wear-resistant steel is 2.5 mm, and the intermediate medium layer and the wear-resistant steel are connected in an explosive composite manner. The manufacturing method of the titanium alloy drill pipe joint comprises the following steps: 1) preparing the wear-resistant belt: cutting the wear-resistant belt with a length of 300 mm, and opening a 30° groove at the end of the wear-resistant belt along the titanium-steel joint surface so as to realize titanium butt welding; bending the titanium alloy drill pipe joint with a diameter of 93.8 mm; the titanium alloy drill pipe joint and the manufacturing method thereof can realize efficient and reliable connection between a titanium alloy drill bit and steel, so that the titanium alloy drill pipe has both corrosion resistance and wear resistance, and effectively improves economic benefits.

Description

Technical Field

[0001] The invention relates to the technical field of drill rods, in particular to a titanium alloy drill rod joint and a manufacturing method thereof. Background Art

[0002] Titanium alloy drill pipes are used in oil and gas production. They have excellent corrosion resistance and high specific strength (the specific gravity is only about 50% of that of nickel-based drill pipes at the same strength), which is extremely beneficial for the development of deep wells and ultra-deep wells with high sulfur content. At the same time, titanium alloys have low elastic modulus and high bending, which are suitable for complex well conditions such as small radius. Titanium alloys also have fatigue properties that steel materials cannot match, which can greatly increase the service life of equipment.

[0003] The drill pipe joint wear belt is an isolation belt with a certain width and thickness along the circumferential direction of the joint. In deep well drilling, extended displacement well drilling and high-angle well drilling, the wear resistance and friction reduction of the wear belt material are used to isolate the outer wall of the drill pipe from the inner wall of the casing, so that the drill pipe joint does not directly contact the casing wall or the well wall, thereby avoiding wear on the outer surface of the drill pipe joint. Commonly used wear belts are made of steel, but steel wear belts are dissolved with titanium to form intermetallic compounds, which are very easy to crack. Therefore, iron and titanium cannot be connected by welding, and the bonding ability of the welded belt and the titanium alloy drill pipe cannot be guaranteed. The cost of using titanium wear belts is too high, which increases the economic cost. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the existing defects and provide a titanium alloy drill rod joint and a manufacturing method thereof, which can realize an efficient and reliable connection between the titanium alloy drill bit and the steel, so that the titanium alloy drill rod has both corrosion resistance and wear resistance, and can effectively solve the problems in the background technology.

[0005] To achieve the above objectives, the present invention provides the following technical solutions: a titanium alloy drill pipe joint, comprising a wear-resistant belt covering its surface, the wear-resistant belt comprising an intermediate medium layer and wear-resistant steel, the intermediate medium layer is used to prevent the titanium alloy drill pipe joint and the wear-resistant steel from breaking.

[0006] As a preferred technical solution of the present invention, the intermediate dielectric layer is titanium or titanium alloy.

[0007] As a preferred technical solution of the present invention, the thickness of the intermediate medium layer is 1.5 to 3 mm, and the thickness of the wear-resistant steel is 2.5 to 3 mm.

[0008] As a preferred technical solution of the present invention, the intermediate medium layer and the wear-resistant steel are connected by rolling composite method.

[0009] As a preferred technical solution of the present invention, the intermediate medium layer and the wear-resistant steel are connected by explosive composite method.

[0010] A method for manufacturing a titanium alloy drill rod joint comprises the following steps:

[0011] 1) Preparation of the wear-resistant belt: The wear-resistant belt is bent according to the diameter of the titanium alloy drill pipe joint, the middle medium layer of the wear-resistant belt is repaired and cleaned, and then cleaned with acetone;

[0012] 2) Preparation of titanium alloy drill pipe joint: The welding parts on the outer surface of the titanium alloy drill pipe joint are machined and ground, and then cleaned with acetone;

[0013] 3) Winding and positioning: Wrap the wear-resistant belt around the titanium alloy drill pipe joint, tighten the clamp and position the wear-resistant belt by spot welding;

[0014] 4) Wear-resistant belt welding: After the wear-resistant belt is wound, the middle medium layer at both ends of the wear-resistant belt is butt-welded. After cleaning the excess height of the weld, the outer layer of wear-resistant steel is butt-welded. Finally, fixed welding is performed 360° along the edge of the wear-resistant belt, and the middle gap is completed by surfacing with titanium wire.

[0015] 5) Heat treatment: Protective atmosphere 400-600℃, keep warm for 2h and then perform stress relief annealing.

[0016] As a preferred technical solution of the present invention, in step 1, a 30° groove is formed at the end of the wear-resistant belt along the intermediate medium layer-wear-resistant steel interface.

[0017] As a preferred technical solution of the present invention, the number of welded wear-resistant belts is 4 to 6, the wear-resistant belts are arranged in parallel, and the spacing between adjacent wear-resistant belts is 1 to 2 mm.

[0018] As a preferred technical solution of the present invention, the surfacing height of the titanium wire in step 4 does not exceed 2 mm.

[0019] As a preferred technical solution of the present invention, the wear-resistant belt and the titanium alloy drill pipe joint are welded by laser fuse welding, with a working distance of 130-180mm, a defocus of 0-20mm, a peak power of 2-4KW, a speed of 2-4mm / min, and a protective drag cover of 15-25L / min.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: the titanium alloy drill pipe joint and its manufacturing method are novel in design and ingenious in conception; the surface layer overcomes the problem of poor wear resistance of the titanium alloy cladding metal and achieves the wear-resistant effect of surfacing steel; the inner layer can meet the requirements of good welding with the matrix titanium alloy; at the same time, the titanium layer in the wear-resistant belt has a certain thickness to ensure the reliability of welding, which not only reduces the economic cost of the titanium alloy drill pipe joint, but also improves the comprehensive wear resistance of the wear-resistant belt, providing reliable guarantee for the improvement of oil and natural gas extraction capacity. DETAILED DESCRIPTION

[0021] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Embodiment 1: A titanium alloy drill pipe joint, comprising a wear-resistant belt covering its surface, the wear-resistant belt comprising an intermediate medium layer and wear-resistant steel, the intermediate medium layer is preferably titanium, the titanium and the wear-resistant steel are connected by explosive composite, the thickness of the titanium is 1.5 mm, the thickness of the wear-resistant steel is 2.5 mm, the width of the wear-resistant belt composed of the titanium and the wear-resistant steel is 8 mm, the titanium and the wear-resistant steel are connected by explosive composite, and the manufacturing method of the titanium alloy drill pipe joint comprises the following steps:

[0023] 1) Preparation of the wear-resistant belt: Cut the wear-resistant belt with a length of 300 mm, and open a 30° groove at the end of the wear-resistant belt along the titanium-steel interface to achieve titanium butt welding; bend the titanium alloy drill pipe joint with a diameter of 93.8 mm; grind and clean the titanium surface of the wear-resistant belt, and clean it with acetone;

[0024] 2) Preparation of titanium alloy drill pipe joint: The welding parts on the outer surface of the titanium alloy drill pipe joint are machined and ground, and then cleaned with acetone;

[0025] 3) Winding and positioning: Wrap four wear-resistant belts around the titanium alloy drill pipe joint, tighten the clamps and position the wear-resistant belts by spot welding. The spacing between adjacent wear-resistant belts is 1 mm.

[0026] 4) Wear-resistant belt welding: After the wear-resistant belt is wrapped, the titanium layers at both ends of the wear-resistant belt are butt-welded. After cleaning the excess height of the weld, the outer layer of wear-resistant steel is butt-welded. Finally, it is fixed and welded 360° along the edge of the wear-resistant belt. The gap between the wear-resistant belts is filled with titanium wire with a diameter of 1.5mm and the height does not exceed 2mm. Laser fuse welding is used between the wear-resistant belt and the titanium alloy drill pipe joint under argon protection, with a working distance of 150mm, a defocusing amount of 10-15mm, a peak power of 3KW, a speed of 4mm / min, and a protective drag cover of 15L / min.

[0027] 5) Heat treatment: Protective atmosphere 500℃, keep warm for 2h and then perform stress relief annealing.

[0028] The shear force between titanium and steel is ≥190Mpa, the shear force between the wear-resistant belt and the titanium alloy drill pipe joint is ≥350Mpa, and the surface hardness of the wear-resistant belt is 60HRC.

[0029] Embodiment 2: A wear-resistant belt of a titanium alloy drill pipe joint, comprising a wear-resistant belt covering the surface thereof, the wear-resistant belt comprising an intermediate medium layer and wear-resistant steel, the intermediate medium layer is preferably titanium, the titanium and the wear-resistant steel are connected by explosive composite, the thickness of the titanium is 2 mm, the thickness of the wear-resistant steel is 3 mm, the width of the wear-resistant belt composed of the titanium and the wear-resistant steel is 10 mm, the titanium and the wear-resistant steel are connected by explosive composite, and the manufacturing method of the titanium alloy drill pipe joint comprises the following steps:

[0030] 1) Preparation of the wear-resistant belt: Cut the wear-resistant belt with a length of 471 mm, and open a 30° groove at the end of the wear-resistant belt along the titanium-steel interface to achieve titanium butt welding; bend the titanium alloy drill pipe joint with a diameter of 147 mm; grind and clean the titanium surface of the wear-resistant belt, and clean it with acetone;

[0031] 2) Preparation of titanium alloy drill pipe joint: The welding parts on the outer surface of the titanium alloy drill pipe joint are machined and ground, and then cleaned with acetone;

[0032] 3) Winding and positioning: Wrap five wear-resistant belts around the titanium alloy drill pipe joint. After tightening the clamp, position the wear-resistant belts by spot welding. The spacing between adjacent wear-resistant belts is 2 mm.

[0033] 4) Wear-resistant belt welding: After the wear-resistant belt is wrapped, the titanium layers at both ends of the wear-resistant belt are butt-welded. After cleaning the excess height of the weld, the outer layer of wear-resistant steel is butt-welded. Finally, it is fixed and welded 360° along the edge of the wear-resistant belt. The gap between the wear-resistant belts is filled with 2mm diameter titanium wire butt welding, and the height does not exceed 2mm. Laser fuse welding is used between the wear-resistant belt and the titanium alloy drill pipe joint under argon protection, with a working distance of 165mm, a defocusing amount of 10-15mm, a peak power of 4KW, a speed of 4mm / min, and a protective drag cover of 20L / min.

[0034] 5) Heat treatment: Protective atmosphere 450℃, keep warm for 2h and then perform stress relief annealing.

[0035] The shear force between titanium and steel is ≥210Mpa, the shear force between the wear-resistant belt and the titanium alloy drill pipe joint is ≥300Mpa, and the surface hardness of the wear-resistant belt is 58HRC.

[0036] Embodiment 3: A wear-resistant belt of a titanium alloy drill pipe joint, comprising a wear-resistant belt covering the surface thereof, the wear-resistant belt comprising an intermediate medium layer and wear-resistant steel, the intermediate medium layer is preferably titanium, the titanium and the wear-resistant steel are connected by explosive composite, the thickness of the titanium is 2 mm, the thickness of the wear-resistant steel is 3 mm, the width of the wear-resistant belt composed of the titanium and the wear-resistant steel is 9 mm, the titanium and the wear-resistant steel are connected by explosive composite, and the manufacturing method of the titanium alloy drill pipe joint comprises the following steps:

[0037] 1) Preparation of the wear-resistant belt: Cut the wear-resistant belt with a length of 646 mm, and open a 30° groove at the end of the wear-resistant belt along the titanium-steel interface to achieve titanium butt welding; bend the titanium alloy drill pipe joint with a diameter of 203 mm; grind and clean the titanium surface of the wear-resistant belt, and clean it with acetone;

[0038] 2) Preparation of titanium alloy drill pipe joint: The welding parts on the outer surface of the titanium alloy drill pipe joint are machined and ground, and then cleaned with acetone;

[0039] 3) Winding and positioning: Wrap six wear-resistant belts around the titanium alloy drill pipe joint. After tightening the clamp, position the wear-resistant belts by spot welding. The spacing between adjacent wear-resistant belts is 2 mm.

[0040] 4) Wear-resistant belt welding: After the wear-resistant belt is wrapped, the titanium layers at both ends of the wear-resistant belt are butt-welded. After cleaning the excess height of the weld, the outer layer of wear-resistant steel is butt-welded. Finally, it is fixed and welded 360° along the edge of the wear-resistant belt. The gap between the wear-resistant belts is filled with titanium wire with a diameter of 1.5mm and the height does not exceed 2mm. Laser fuse welding is used between the wear-resistant belt and the titanium alloy drill pipe joint under argon protection, with a working distance of 180mm, a defocusing amount of 10-15mm, a peak power of 4KW, a speed of 3mm / min, and a protective drag cover of 25L / min.

[0041] 5) Heat treatment: Protective atmosphere 500℃, keep warm for 2h and then perform stress relief annealing.

[0042] The shear force between titanium and steel is ≥200Mpa, the shear force between the wear-resistant belt and the titanium alloy drill pipe joint is ≥320Mpa, and the surface hardness of the wear-resistant belt is 62HRC.

[0043] Comparative Example: A steel wear-resistant belt with a length of 470 mm was selected and welded to a titanium alloy drill pipe joint with a diameter of 140 mm using the same welding method as in Example 1-3.

[0044] The shear force between the steel wear-resistant belt and the titanium alloy drill pipe joint is ≥50Mpa, the bonding ability is low, and the wear-resistant belt is easy to fall off during the drilling process, which increases the difficulty of mining.

[0045] The present invention utilizes a composite of titanium and wear-resistant steel as the wear-resistant belt substrate, and the inner layer of titanium and the titanium alloy drill bit joint are reliably connected through welding, so that the titanium alloy drill rod has both corrosion resistance and wear resistance during mining. After welding, a stress relief heat treatment process is used to eliminate the stress generated by welding, thereby improving the fatigue performance of the joint and reducing economic benefits. This is a major breakthrough in the exploitation of oil and natural gas.

[0046] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for manufacturing a titanium alloy drill pipe joint, characterized in that: The titanium alloy drill pipe joint includes a wear-resistant belt covering its surface, the wear-resistant belt includes an intermediate medium layer and wear-resistant steel, the intermediate medium layer is used to prevent the titanium alloy drill pipe joint and the wear-resistant steel from breaking, the intermediate medium layer is titanium or titanium alloy, and the intermediate medium layer and the wear-resistant steel are connected by rolling compounding or explosive compounding; The preparation method thereof comprises the following steps: 1) Preparation of the wear-resistant belt: The wear-resistant belt is bent according to the diameter of the titanium alloy drill pipe joint, the middle medium layer of the wear-resistant belt is repaired and cleaned, and then cleaned with acetone; 2) Preparation of titanium alloy drill pipe joint: The welding parts on the outer surface of the titanium alloy drill pipe joint are machined and ground, and then cleaned with acetone; 3) Winding and positioning: Wrap the wear-resistant belt around the titanium alloy drill pipe joint, tighten the clamp and position the wear-resistant belt by spot welding. The number of welded wear-resistant belts is 4 to 6, and the wear-resistant belts are arranged in parallel. The spacing between adjacent wear-resistant belts is 1 to 2 mm. 4) Wear-resistant belt welding: After the wear-resistant belt is wound, the middle medium layer at both ends of the wear-resistant belt is butt-welded, and the outer wear-resistant steel is butt-welded after cleaning the weld excess height. Finally, fixed welding is performed 360° along the edge of the wear-resistant belt, and the middle gap is completed by titanium wire. 5) Heat treatment: Protective atmosphere 400-600℃, keep warm for 2h and then perform stress relief annealing.

2. The method for manufacturing a titanium alloy drill rod joint according to claim 1, characterized in that: The thickness of the intermediate medium layer is 1.5-3 mm, and the thickness of the wear-resistant steel is 2.5-3 mm.

3. The method for manufacturing a titanium alloy drill rod joint according to claim 1, characterized in that: In the step 1, a 30° groove is formed at the end of the wear-resistant belt along the intermediate medium layer-wear-resistant steel interface.

4. The method for manufacturing a titanium alloy drill rod joint according to claim 1, characterized in that: The surfacing height of the titanium wire in step 4 does not exceed 2 mm.

5. The method for manufacturing a titanium alloy drill rod joint according to claim 1, characterized in that: The wear-resistant belt and the titanium alloy drill pipe joint are welded by laser fuse welding, with a working distance of 130-180 mm, a defocusing amount of 0-20 mm, a peak power of 2-4 KW, a speed of 2-4 mm / min, and a protective drag cover of 15-25 L / min.