Anti-corrosion and wear-resistant drill rod structure

Abstract

A corrosion-resistant and wear-resistant drill rod structure comprises a plurality of drill rods and drill bits, connecting structures are arranged between the drill rods and between the drill rods and the drill bits, and each connecting structure comprises a first central circular truncated cone arranged below an upper end component and an annular boss arranged on a lower end component. The outer side of the central circular truncated cone and the inner side of the annular boss are provided with threads matched with each other, the outer side of the annular boss is sleeved with a sacrificial anode ring, the outer diameter of the annular boss is smaller than that of the lower end component, and the difference value of the outer diameter of the annular boss and the outer diameter of the lower end component is larger than the thickness of the sacrificial anode ring. The sacrificial anode ring is fixed through the connecting structure, the sacrificial anode ring is not prone to being abraded by external rock-soil machinery, meanwhile, the sacrificial anode ring plays a role in protecting the connecting structure of the drill rod from being abraded by rock-soil, the sacrificial anode ring can be replaced after being abraded, and the cost is reduced. And whether the sacrificial anode ring is perforated or not can be detected in time, so that replacement of the sacrificial anode ring is prompted.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of drill bits, and particularly relates to a corrosion-resistant and wear-resistant drill rod structure. BACKGROUND

[0002] With the increase of the development time of oil and gas fields and the service life of equipment, especially the exploration and development of high-sulfur oil and gas reservoirs and other oil and gas reservoirs containing acidic corrosive media, corrosion and wear have brought increasingly prominent adverse effects on the safe and stable operation of equipment in the oil and gas industry.

[0003] Drill rods are important tools in underground resource exploration and development, accounting for 80-90% of the length of the entire drill string; drill rods refer to steel pipes used for drilling, which are usually composed of several pipe sections, and common drill rod materials include ordinary carbon steel and chromium-molybdenum alloy steel; under normal circumstances, drill rods are recycled, and during service, they are subjected to long-term alternating stress such as internal and external pressure, twisting, bending, and vibration; at the same time, they are affected by corrosive media such as dissolved oxygen, carbon dioxide, hydrogen sulfide, and chloride ions in the drilling fluid and corrosive media in the underground fluid, as well as long-term wear and erosion by the drilling fluid. Corrosion accelerates the wear of the drill rod, and wear increases the stress on the drill rod, exacerbating the stress fatigue of the drill rod. The combined effect of corrosion, wear, and alternating stress makes the drill rod a frequent failure point during drilling.

[0004] Chinese patent CN118726986A discloses a corrosion-resistant and wear-resistant drill rod and a preparation method thereof, which improves the corrosion-resistant and wear-resistant performance of the drill rod by preparing a sacrificial anode and a wear-resistant layer on the drill rod body using a laser process. The defect of this method is that a special laser cladding process is required to prepare the sacrificial anode on the drill rod body, which is costly, and after the sacrificial anode is consumed during use, it needs to be restored by laser cladding process, otherwise the drill rod cannot be reused. At the same time, the consumption state of the sacrificial anode cannot be detected during drilling. SUMMARY

[0005] To overcome the defects of the prior art, the application discloses a corrosion-resistant and wear-resistant drill rod structure.

[0006] The corrosion-resistant and wear-resistant drill rod structure disclosed by the application comprises multiple drill rods and a drill bit, and a connecting structure is arranged between the drill rods and between the drill rods and the drill bit. The connecting structure comprises a first central circular table arranged below an upper end part and an annular boss arranged on a lower end part. A thread is arranged on the outer side of the first central circular table and the inner side of the annular boss, and the outer side of the annular boss is sleeved with a sacrificial anode ring. The outer diameter of the annular boss is smaller than the outer diameter of the lower end part, and the difference between the outer diameters of the annular boss and the lower end part is greater than the thickness of the sacrificial anode ring.

[0007] Preferably, the outer side of the annular boss and the inner side of the sacrificial anode ring are respectively provided with external threads and internal threads which are matched with each other.

[0008] Preferably, the upper end part and the lower end part are centrally provided with water channels which are matched in position, the drill bit part is provided with nozzles, and a water pressure sensor is arranged in the drill rod.

[0009] Preferably, the lower end part is provided with a detection flow channel which is communicated with the water channel at one end and located at the outer side of the annular boss at the other end.

[0010] Preferably, the detection flow channel comprises a horizontal flow channel and a vertical slot which is communicated with the horizontal flow channel, the horizontal flow channel comprises a horizontal slot which is arranged at the top of the lower end part and located at the center of the annular boss, and a through slot which is communicated with the horizontal slot and penetrates through the annular boss, and the through slot is communicated with the vertical slot which is arranged on the surface of the annular boss at the end.

[0011] Preferably, the horizontal slot is an open slot structure which is arranged at the top of the lower end part, the vertical slot is an open slot structure which is arranged on the outer wall of the annular boss, and the through slot is a straight-through slot which runs in a direction perpendicular to the circular boundary of the annular boss.

[0012] Preferably, the vertical slot extends upward from the bottom and is arranged at the center of the height of the annular boss at the end.

[0013] Preferably, the annular boss is centrally provided with a horizontally laid filter screen which covers the horizontal slot, the central part of the lower end part surrounded by the annular boss and not provided with the horizontal slot is a second central circular platform, the first central circular platform of the upper end part is centrally provided with a circular recess, and the radius of the circular recess is greater than the radius of the second central circular platform.

[0014] Preferably, a wear-resistant ring is sleeved on the outer side of the drill rod body.

[0015] By using the anti-corrosion and wear-resistant drill rod structure, the sacrificial anode ring is fixed by the connecting structure, and the sacrificial anode ring is not easy to be abraded by external rock-soil machines, and the sacrificial anode ring itself also plays a role in protecting the drill rod connecting structure from being abraded by rock-soil, and the sacrificial anode ring can be replaced after being worn out, and whether the sacrificial anode ring is perforated can be detected in time, so as to prompt the replacement of the sacrificial anode ring. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a specific embodiment combination schematic diagram of the anti-corrosion and wear-resistant drill rod structure. Figure 2 It is an explosion schematic diagram of each part of another specific embodiment of the anti-corrosion and wear-resistant drill rod structure. Figure 3Figure 1 is a combined profile schematic diagram of another specific embodiment of the anti-corrosion and wear-resistant drill pipe structure of the present application; Figure 4 Figure 1 is a combined profile schematic diagram of another specific embodiment of the anti-corrosion and wear-resistant drill pipe structure of the present application; In the figure, the figure reference name is 1-upper end part, 2-lower end part, 3-sacrificial anode ring, 4-wear-resistant ring, 5-filter screen, 6-waterway, 11-first central circular platform, 12-circular recess, 21-annular boss, 22-horizontal flow channel, 221-horizontal groove, 222-penetrating groove, 23-vertical groove, and 24-second central circular platform. Specific embodiments

[0017] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0018] As Figure 1 shown, the anti-corrosion and wear-resistant drill pipe structure of the present application includes multiple drill pipes and a drill bit, and a connecting structure is arranged between the drill pipes and between the drill pipes and the drill bit, the connecting structure includes a first central circular platform 11 arranged below the upper end part 1 and an annular boss 21 arranged on the lower end part 2, a thread matched with each other is arranged on the outer side of the first central circular platform 11 and the inner side of the annular boss 21, and a sacrificial anode ring 3 is sleeved on the outer side of the annular boss.

[0019] The outer diameter of the annular boss is smaller than the outer diameter of the lower end part, and the difference between the two is greater than the thickness of the sacrificial anode ring, as Figure 1 shown, so that after installation, the outer side of the sacrificial anode ring exposed to the outside is still on the inner side of the lower end part, and it is not easy to be directly worn by external sandstone during rotation of the drill pipe, causing physical loss of the sacrificial anode.

[0020] Specifically, the sacrificial anode ring material can be a metal material with a lower potential than the drill pipe body material, such as the sacrificial anode material disclosed in Chinese patent CN118726986A, the upper end part is a drill pipe, and the lower end part can be a drill pipe or a drill bit. When the upper end part and the lower end part are connected, the sacrificial anode ring is first sleeved on the outer side of the annular boss, and the inner diameter of the sacrificial anode ring and the outer diameter of the annular boss are generally gap-fitted, so that they form good sealing and electrical contact.

[0021] In one specific embodiment, an external thread is arranged on the outer side of the annular boss 21, an internal thread is formed on the inner side of the sacrificial anode ring 3 when the sacrificial anode ring is manufactured, and during assembly, the sacrificial anode ring is pre-tightened on the outer side of the annular boss by the thread, and then the central circular platform of the upper end part is tightened on the inner side of the annular boss of the lower end part, so that the upper end part and the lower end part are connected together, and the sacrificial anode ring is fixed between the upper end part and the lower end part.

[0022] In the installation, the sacrificial anode ring can also be heated as a whole, for example, the sacrificial anode ring of aluminum alloy material is heated to 200-400 degrees Celsius, and the specific heating temperature is determined according to the specific material composition of the sacrificial anode ring and actual experience. After heating, it is sleeved outside the annular boss, and after cooling, the sacrificial anode ring shrinks to form a firm seal and electrical connection.

[0023] By installing the sacrificial anode ring at the drill pipe joint, the corrosion protection of the drill pipe body is realized through the loss of the sacrificial anode ring itself. After the sacrificial anode ring is consumed, it can be directly removed by mechanical external force or heating cooperation, and a new sacrificial anode ring is replaced for recycling.

[0024] Figure 1 In the specific embodiment shown, the upper end part and the lower end part are centrally provided with water channels 6. After the combination of multiple drill pipes and drill bits, the water channels are mutually penetrated. Nozzles are arranged at the drill bit part. During drilling operation, water is sprayed outside through the nozzles to soften the mud layer, provide lubrication and reduce the temperature of the drill bit. A booster pump is arranged outside the well for water injection into the water channel. The above water-spraying drill bit is a prior art in the field. A water pressure sensor is usually arranged in the drill pipe to adjust the output flow of the booster pump by detecting the water pressure in the water channel.

[0025] Based on the drill pipe provided with the water channel 6, as shown in the specific embodiment, Figure 1 In the specific embodiment shown, the lower end part is provided with a detection flow channel having one end communicated with the water channel and the other end located outside the annular boss 21. When the sacrificial anode ring 3 is sleeved on the annular boss 21, the detection flow channel is sealed, and the water channel and the detection flow channel are filled with water during drilling of the drill bit. As the sacrificial anode ring wears and consumes, when the sacrificial anode ring wears and consumes to expose the detection flow channel, the water pressure of the detection flow channel and the water channel communicated with the detection flow channel will rapidly decrease before the booster pump increases the flow, and the water pressure decrease can be detected by the water pressure sensor arranged in the drill pipe. At this time, it can be judged that a considerable part of the sacrificial anode ring of the drill pipe downhole may have been corroded, and the drill pipe needs to be taken out and the sacrificial anode ring needs to be replaced.

[0026] Figure 1 In the specific embodiment shown, the detection flow channel has multiple parts and is symmetrically distributed around the center of the lower end part. Each detection flow channel includes a horizontal flow channel and a vertical groove 23 communicated with the horizontal flow channel. The horizontal flow channel includes a horizontal groove 221 opened at the top of the lower end part and located in the center of the annular boss, and a through groove 222 communicated with the horizontal groove and penetrating the annular boss. The end of the through groove is communicated with the vertical groove 23 arranged on the surface of the annular boss. The horizontal groove 221 is an open groove structure opened at the top of the lower end part. The vertical groove 23 is an open groove structure opened on the outer wall of the annular boss 21. The through groove 222 is a straight-through groove running in a direction perpendicular to the circular boundary of the annular boss 21.

[0027] The open slot structure and straight-through slot facilitate processing and cleaning, and the mechanical strength of the connection is less damaged, as shown in Figure 1 When the sacrificial anode ring and the upper end part are installed, the upper end of the horizontal slot is closed by the lower surface of the upper end part to form a closed structure, and the side of the vertical slot is closed by the sacrificial anode ring to form a closed structure, thereby forming a whole sealed slot body connected with the through slot, and the horizontal slot is communicated with the water channel located in the center of the lower end part.

[0028] According to the actual drilling experience, the lower part of the sacrificial anode is more prone to wear and corrosion due to easier contact with underground water and rock, so the lower part of the sacrificial anode is more prone to wear and corrosion than the upper part. The vertical slot extends upward from the bottom, and the end can be arranged at the center of the height of the annular boss. When the sacrificial anode ring is eroded at any height in the lower half, the original closed vertical slot is exposed, thereby exposing the entire detection flow channel.

[0029] At the same time, the detection flow channel also has the advantage of being able to spray water outward. During use, part of the underground water with corrosion and solid particles will inevitably be brought into the water channel, corroding the inner wall of the water channel. The inner wall of the water channel is usually pre-processed to have an insulating wear-resistant and corrosion-resistant coating. The detection flow channel enables the inner side of the sacrificial anode ring to be electrically connected to the internal water channel through the detection flow channel, thereby reducing the electrical resistance from the side wall of the water channel to the sacrificial anode ring. Thus, the sacrificial anode ring not only protects the outer surface of the drill pipe, but also protects the side wall of the internal water channel of the drill pipe body. At the same time, part of the solid particles will enter the horizontal flow channel when moving in the vertical water channel with the water flow, thereby depositing in the horizontal flow channel. When the sacrificial anode ring is replaced, it can be cleaned together, and the wear on the side wall of the vertical water channel is also reduced.

[0030] When the sacrificial anode ring is consumed, the vertical slot is exposed, enabling the detection flow channel to be directly connected to the outside, resulting in a rapid drop in the internal water pressure of the water channel in the center of the drill pipe. The operator can discover that the sacrificial anode ring needs to be replaced. By arranging multiple detection flow channels, the detection probability of perforation at any position of the sacrificial anode ring is increased.

[0031] Figure 1In the specific embodiment shown, to avoid the external sewage containing solid particles from entering the water channel after the sacrifice anode ring is perforated, causing the solid particles to accumulate in the water channel, which is difficult to clean due to the perforation through the entire drill rod, a horizontally laid filter screen 5 can be arranged in the center of the annular boss, covering the horizontal groove 221 above, when the external sewage enters the horizontal groove through the through groove, it is blocked by the filter screen, at the same time, to form a complete water channel, the horizontal groove is not directly connected to the water channel, and the central part of the lower end part surrounded by the annular boss is not provided with a horizontal groove 221 in the area of the second central circular platform 24, and the circular recess 12 is arranged in the center of the first central circular platform 24 of the upper end part, and the water channel is arranged in the center of the circular recess, and the radius of the circular recess is greater than the radius of the second central circular platform 24, so that when the upper end part 1 and the lower end part 2 are installed together, the circular recess 12 becomes a passage connecting the water channel and the horizontal groove. After the circular recess and the second central circular platform are arranged, the filter screen can filter the solid particles in the external water flow into the water channel, and the filter screen is tightly compressed by the first central circular platform of the upper end structure and the part of the lower end structure with the horizontal groove, so that even if the internal and external water pressure difference is large, the filter screen will not be displaced, and continuous filtering can be performed when the sacrifice anode ring is perforated.

[0032] To improve the wear resistance, a wear-resistant ring can be sleeved outside the drill rod body, for example, in the specific embodiment shown, a wear-resistant ring is sleeved outside the upper end part of the drill rod body. Figure 1 In the specific embodiment shown, a wear-resistant ring is sleeved below the upper end part, and the wear-resistant ring can be fixed outside the drill rod by a similar method to the sacrifice anode ring, such as threaded connection or preheating shrinkage, facilitating replacement after wear. The thickness of the wear-resistant ring is set according to experience, so that the replacement period of the wear-resistant ring is later than that of the sacrifice anode ring, and the wear degree of the wear-resistant ring can be observed when the sacrifice anode ring is replaced to decide whether to replace it. Figure 1 In the specific embodiment shown, the edge of the wear-resistant ring protrudes from the connecting structure by a part, and mechanically fixes the sacrifice anode ring, so that even if the sacrifice anode ring is broken due to impact, it will not fall off from the connecting structure.

[0033] The anti-corrosion and wear-resistant drill rod structure of the present application uses the connecting structure to fix the sacrifice anode ring, and makes the sacrifice anode ring not easy to be worn by external rock-soil machinery, and the sacrifice anode ring itself also plays a role in protecting the connecting structure of the drill rod from being worn by rock-soil, and can be replaced after wear, and whether the sacrifice anode ring is perforated can be detected in time, prompting the replacement of the sacrifice anode ring.

[0034] The foregoing is merely preferred embodiments of the present application, and the preferred embodiments in each preferred embodiment can be arbitrarily combined and used if not obviously contradictory or with a certain preferred embodiment as a prerequisite. The embodiments and specific parameters in the embodiments are merely for the purpose of clearly describing the inventor's verification process and are not intended to limit the patent protection scope of the present application. The patent protection scope of the present application is still subject to its claims, and any equivalent structural changes made by using the content of the specification and drawings of the present application shall also be included in the protection scope of the present application.

Claims

1. A corrosion-resistant and wear-resistant drill rod structure, comprising multiple drill rod sections and a drill bit, wherein connecting structures are provided between the drill rod sections and between the drill rod and the drill bit, characterized in that, The connection structure includes a first central truncated cone (11) disposed below the upper component (1) and an annular boss (21) disposed on the lower component (2). The outer side of the first central truncated cone (11) and the inner side of the annular boss (21) are provided with mutually cooperating threads. A sacrificial anode ring (3) is sleeved on the outer side of the annular boss. The outer diameter of the annular boss (21) is smaller than the outer diameter of the lower component (2), and the difference between the outer diameters of the annular boss (21) and the lower component (2) is greater than the thickness of the sacrificial anode ring (3).

2. The corrosion-resistant and wear-resistant drill rod structure as described in claim 1, characterized in that, The outer side of the annular boss (21) and the inner side of the sacrificial anode ring (3) are respectively provided with mutually cooperating external threads and internal threads.

3. The corrosion-resistant and wear-resistant drill rod structure as described in claim 1, characterized in that, The upper part (1) and the lower part (2) are provided with a water channel (6) in the center, the drill bit is provided with a nozzle, and a water pressure sensor is provided inside the drill rod.

4. The corrosion-resistant and wear-resistant drill rod structure as described in claim 3, characterized in that, The lower end component (2) is provided with a detection channel that is connected to the waterway (6) at one end, and the other end of the detection channel is located outside the annular boss (21).

5. The corrosion-resistant and wear-resistant drill rod structure as described in claim 4, characterized in that, The detection channel includes a horizontal channel (22) and a vertical groove (23) connected to the horizontal channel. The horizontal channel includes a horizontal groove (221) located at the center of the annular boss (21) on the top of the lower end component (2), and a through groove (222) connected to the horizontal groove and passing through the annular boss. The end of the through groove (222) is connected to the vertical groove (23) provided on the surface of the annular boss (21).

6. The corrosion-resistant and wear-resistant drill rod structure as described in claim 5, characterized in that, The horizontal groove (221) is an open groove structure opened on the top of the lower part (2), the vertical groove (23) is an open groove structure opened on the outer wall of the annular boss (21), and the through groove (222) is a straight through groove that runs along the direction perpendicular to the circular boundary of the annular boss (21).

7. The corrosion-resistant and wear-resistant drill rod structure as described in claim 5, characterized in that, The vertical groove (23) extends upward from the bottom and ends at the center of the height of the annular boss (21).

8. The corrosion-resistant and wear-resistant drill rod structure as described in claim 5, characterized in that, A horizontally laid filter screen (5) is provided in the center of the annular boss (21), and the filter screen (5) covers the horizontal groove (221). The area in the center of the lower part of the component surrounded by the annular boss where the horizontal groove is not opened is the second central truncated cone (24). A circular recess (12) is provided in the center of the first central truncated cone (11) of the upper part, and the radius of the circular recess (12) is larger than the radius of the second central truncated cone (24).

9. The corrosion-resistant and wear-resistant drill rod structure as described in claim 1, characterized in that, A wear-resistant ring (4) is fitted on the outside of the drill pipe body.

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