High-strength and high-torsion-resistance drill rod

Abstract

A high-strength and high-torsion-resistance drill rod relates to the technical field of drilling tools and comprises a drill rod body, upsetting ends are arranged at the two ends of the drill rod body, and an internal thread connector and an external thread connector are arranged on the outer sides of the two upsetting ends respectively. An internal thread main step seal, an internal thread extension reaming hole, an internal thread, an internal thread extension small-diameter cylinder and an internal thread thrust step are sequentially arranged in the internal thread joint from left to right; an external thread main step seal, an external thread cylinder, an external thread, an external thread small-diameter nose end and an external thread thrust step are sequentially arranged on the external thread joint from left to right; the inner thread and the outer thread are both trapezoidal threads, a large arc structure is adopted between the bottoms of every two adjacent threads, the whole drill rod is made of chromium-molybdenum alloy structural steel, and the upsetting ends at the two ends of the drill rod body can increase the compression resistance and the tensile strength; after the internal and external thread joints are connected, the connector has higher torsional strength and is suitable for the working condition of ultra-deep well drilling.

Description

Technical Field

[0001] The utility model relates to the technical field of drilling tools, in particular to a high-strength and high-torsion resistance drill rod. Background Art

[0002] Drill pipe is a crucial tool in oil and gas exploration and development, and a vital component of the drill string system. Its purpose is to transport drilling mud to the drill bit and, along with the drill bit, to raise, lower, or rotate the bottom hole assembly. Drill pipe must be able to withstand significant internal and external pressure, as well as twisting, bending, and vibration. It can be used multiple times during the oil and gas extraction and refining process.

[0003] During ultra-deep well drilling, ordinary drill pipes cannot withstand the heavy weight and high torque, which can lead to problems such as pipe breakage and thread torque overload failure. Therefore, a high-strength and high-torsion-resistant drill pipe is urgently needed to solve the above technical problems. Utility Model Content

[0004] In view of the above shortcomings of the existing technology, the purpose of the present invention is to provide a high-strength and high-torsion-resistant drill pipe, which can solve the problems of ordinary drill pipes breaking and thread torque overload failure due to being unable to withstand heavy weight and high torque during ultra-deep well drilling.

[0005] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0006] A high-strength and high-torsion-resistant drill pipe includes a drill pipe body, both ends of the drill pipe body are provided with upset ends, and the outer sides of the two upset ends are respectively provided with an internal thread joint and an external thread joint; the internal thread joint is provided with an internal thread main step seal, an internal thread extended reaming, an internal thread, an internal thread extended small diameter cylinder and an internal thread thrust step from left to right, and the external thread joint is provided with an external thread main step seal, an external thread cylinder, an external thread, an external thread small diameter nose end and an external thread thrust step from left to right; the thread tooth profiles of the internal thread and the external thread are both trapezoidal threads, and a large arc structure is used between the bottoms of two adjacent thread teeth.

[0007] Preferably, the outer diameter of the upset end portion is larger than the outer diameter of the drill rod body, and the inner diameter of the upset end portion is smaller than the inner diameter of the drill rod body.

[0008] Preferably, the outer diameter of the internal threaded joint is equal to the outer diameter of the external threaded joint, and the inner diameter of the internal threaded joint is equal to the inner diameter of the external threaded joint.

[0009] Preferably, the inner transition region between the upsetting end and the drill rod body adopts a smooth structure, and the length of the inner transition region is ≥150 mm.

[0010] Preferably, the external thread cylinder is clearance-fitted with the internal thread extended reaming hole, and the external thread minor diameter nose is interference-fitted with the internal thread extended minor diameter cylinder.

[0011] Compared with the prior art, the beneficial effects of the present invention are:

[0012] 1. The drill rod of the present invention is made of chromium-molybdenum alloy structural steel as a whole. The upset ends at both ends of the drill rod body can increase the compressive and tensile strength. The upset ends are connected to the joints by inertia friction welding. The welds are annealed to relieve stress. The welds are flattened and then locally tempered. The mechanical properties after tempering are close to those of the drill rod body. The overall performance of the weld is more than 110% of the overall performance of the drill rod body, avoiding breakage.

[0013] 2. After the internal and external threaded joint of the present invention is connected, the external thread cylinder and the internal thread extended reaming hole, the external thread minor diameter nose and the internal thread extended minor diameter cylinder, the external thread thrust step and the internal thread thrust step are in contact respectively, so that the threaded joint has high torsional resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0015] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0016] Figure 2 This is a schematic diagram of the connection structure of the internal and external threaded joint of the present utility model;

[0017] Figure 3 for Figure 2 Enlarged view of point A in the middle.

[0018] Description of reference numerals:

[0019] 1-drill pipe body, 2-upsetting end, 3-internal thread joint, 30-internal thread main step seal, 31-internal thread extended reaming, 32-internal thread, 33-internal thread extended small diameter cylinder, 34-internal thread thrust step, 4-external thread joint, 40-external thread main step seal, 41-external thread cylinder, 42-external thread, 43-external thread small diameter nose, 44-external thread thrust step, 5-inner transition area. DETAILED DESCRIPTION

[0020] The following describes the invention of the present invention in detail by way of examples in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Example

[0021] like Figures 1 to 3 As shown, the utility model discloses a high-strength and high-torsion resistance drill pipe, including a drill pipe body 1, wherein the drill pipe body 1 is made of chromium-molybdenum alloy structural steel, and its tempered yield strength steel grade is ≥165Ksi; both ends of the drill pipe body 1 are forged with upsetting ends 2, the outer diameter of the upsetting end 2 is larger than the outer diameter of the drill pipe body 1, and the inner diameter of the upsetting end 2 is smaller than the inner diameter of the drill pipe body 1; the inner transition area 5 between the upsetting end 2 and the drill pipe body 1 adopts a smooth structure, and the length of the inner transition area 5 is 160mm; the outer sides of the two upsetting ends 2 are respectively welded with an internal thread joint 3 and an external thread joint 4 by inertia friction welding, the welds are annealed to relieve stress, the welds are flattened and then locally tempered, and the mechanical properties after tempering are close to those of the drill pipe body 1, and the overall performance of the welds is more than 110% of the overall performance of the drill pipe body 1, which is conducive to avoiding fracture.

[0022] The internal thread joint 3 and the external thread joint 4 are both made of chromium-molybdenum alloy structural steel; the outer diameter of the internal thread joint 3 is equal to the outer diameter of the external thread joint 4, and the inner diameter of the internal thread joint 3 is equal to the inner diameter of the external thread joint 4; the internal thread joint 3 is provided with an internal thread main step seal 30, an internal thread extended reaming hole 31, an internal thread 32, an internal thread extended minor diameter cylinder 33 and an internal thread thrust step 34 from left to right, and the external thread joint 4 is provided with an external thread main step seal 40, an external thread cylinder 41, an external thread 42, an external thread minor diameter nose end 43 and an external thread thrust step 44 from left to right; the external thread cylinder 41 is clearance-fitted with the internal thread extended reaming hole 31, and the external thread minor diameter nose end 43 is interference-fitted with the internal thread extended minor diameter cylinder 33; the thread tooth profiles of the internal thread 32 and the external thread 42 are both trapezoidal threads, and a large arc structure is adopted between the bottoms of two adjacent thread teeth.

[0023] During use, the drill pipe of the present invention is connected to the upper portion of the drill string. The drill pipe is entirely constructed of chromium-molybdenum alloy structural steel. The upset ends 2 at both ends of the drill pipe body 1 increase compressive and tensile strength. The upset ends 2 are connected to the joint using inertia friction welding. The weld seam is annealed for stress relief, flattened, and then locally tempered. The mechanical properties of the tempered weld are close to those of the drill pipe body 1, and the overall performance of the weld is greater than 110% of that of the drill pipe body 1, preventing breakage. After the internal and external threaded joint is connected, the externally threaded cylinder 41 and the internally threaded extended bore 31, the externally threaded minor-diameter nose 43 and the internally threaded extended minor-diameter cylinder 33, and the externally threaded thrust step 44 and the internally threaded thrust step 34, respectively, contact each other, giving the threaded joint high torsion resistance. This high-strength, torsion-resistant drill pipe of the present invention can withstand the weight and torque of the entire drill string in ultra-deep wells, demonstrating its high practicality.

[0024] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and application concept of the present invention, should be covered by the protection scope of the present invention.

Claims

1. A high-strength and high-torsion resistance drill rod, comprising a drill rod body (1), characterized in that: Both ends of the drill pipe body (1) are provided with upset ends (2), and the outer sides of the two upset ends (2) are respectively provided with an internal thread joint (3) and an external thread joint (4); the internal thread joint (3) is provided with an internal thread main step seal (30), an internal thread extended reamer (31), an internal thread (32), an internal thread extended small diameter cylinder (33) and an internal thread thrust step (34) in sequence from left to right, and the external thread joint (4) is provided with an external thread main step seal (40), an external thread cylinder (41), an external thread (42), an external thread small diameter nose end (43) and an external thread thrust step (44) in sequence from left to right; the thread tooth profiles of the internal thread (32) and the external thread (42) are both trapezoidal threads, and a large arc structure is adopted between the bottoms of two adjacent thread teeth.

2. A high-strength and high-torsion-resistant drill pipe according to claim 1, characterized in that: The outer diameter of the upsetting end portion (2) is larger than the outer diameter of the drill rod body (1), and the inner diameter of the upsetting end portion (2) is smaller than the inner diameter of the drill rod body (1).

3. The high-strength and high-torsion-resistant drill pipe according to claim 1, characterized in that: The outer diameter of the internal threaded joint (3) is equal to the outer diameter of the external threaded joint (4), and the inner diameter of the internal threaded joint (3) is equal to the inner diameter of the external threaded joint (4).

4. The high-strength and high-torsion-resistant drill pipe according to claim 1, characterized in that: The inner transition region (5) between the upsetting end (2) and the drill rod body (1) adopts a smooth structure, and the length of the inner transition region (5) is ≥150 mm.

5. The high-strength and high-torsion-resistant drill pipe according to claim 1, characterized in that: The external thread cylinder (41) is clearance-fitted with the internal thread extended reamer (31), and the external thread minor diameter nose (43) is interference-fitted with the internal thread extended minor diameter cylinder (33).

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