Manufacturing method of drill rod and drill rod device

Abstract

The invention discloses a drill rod manufacturing method and a drill rod device, and particularly relates to the field of petroleum drilling operation, the drill rod is made of super 13Cr, and the method comprises the steps that a pre-machined pipe body is subjected to first heat treatment, and a drill rod pipe body is obtained; performing second heat treatment and thread machining on the joint blank to obtain a threaded joint; and the drill rod pipe body and a threaded connector are subjected to friction compression joint, third heat treatment is conducted on a welding seam obtained after friction compression joint, and the drill rod is obtained. The drill rod obtained through the manufacturing method of the drill rod can be effectively used in the drilling environment containing high CO2 and Cl <->, and the problems of drill rod piercing leakage and breakage caused by corrosion are solved.

Description

Technical Field

[0001] This application relates to the field of oil drilling operations. Specifically, it relates to a manufacturing method of drill pipes and a drill pipe device. Background Art

[0002] Currently in drilling technology, polysulfonate drilling fluid is commonly used in China. However, since polysulfonate drilling fluid decomposes to produce CO2 at high temperatures, and CO2 dissolves in water and decomposes into HCO 3- and CO 3- ,HCO 3- has extremely strong corrosiveness. Especially in the southwestern region, a lot of KCl is added to polysulfonate drilling fluid, and Cl - (anion) adsorbs on the surface of the drill pipe, the metal presents an activated state, and a passive corrosion cell is formed with the damage of the passive film, and the drill pipe is easily corroded into small holes. Summary of the Invention

[0003] In view of this, this application aims to provide a manufacturing method of drill pipes and a drill pipe device, aiming to solve the problem that drill pipes are easily corroded by CO2 and Cl - in the related art.

[0004] The first aspect of the embodiment of this application provides a manufacturing method of drill pipes. The material of the drill pipe is super 13Cr. The method includes:

[0005] Obtaining a drill pipe body by performing a first heat treatment on a pre-processed pipe body;

[0006] Obtaining a threaded joint by performing a second heat treatment and threading on a joint blank;

[0007] Performing friction press fitting on the drill pipe body and the threaded joint, and performing a third heat treatment on the weld after friction press fitting to obtain the drill pipe.

[0008] Optionally, the obtaining a drill pipe body by performing a first heat treatment on a pre-processed pipe body includes:

[0009] Coating a high-temperature resistant coating on the surface of the pre-processed pipe body to obtain a first pipe body;

[0010] Heating the first pipe body to a preset temperature and keeping it warm for a preset total duration to obtain a second pipe body;

[0011] After cooling the second pipe body in the air to a preset cooling temperature, placing it in water to cool it to room temperature to obtain a third pipe body;

[0012] Heating the third pipe body to a preset tempering temperature and keeping it warm for a preset tempering time. After the third pipe body is cooled in the air, the drill pipe body is obtained.

[0013] Optionally, heating the first tube body to a preset temperature and maintaining the temperature for a preset total duration to obtain a second tube body includes:

[0014] Heating the first tube body to a preset upper limit temperature and maintaining the temperature for a first preset duration;

[0015] After each maintenance of the first preset duration, heating the first tube body to the preset lower limit temperature and maintaining the temperature for a second preset duration;

[0016] After each maintenance of the second preset duration, heating the first tube body to the preset upper limit temperature and maintaining the temperature for a first preset duration;

[0017] When the total heat preservation duration reaches the preset total duration, the second tube body is obtained.

[0018] Optionally, before coating the surface of the pre-processed tube body with a high-temperature resistant coating to obtain the first tube body, the method further includes:

[0019] Thickening the tube ends of the pre-processed tube body to a preset size to obtain a target pre-processed tube body;

[0020] Coating the surface of the pre-processed tube body with a high-temperature resistant coating to obtain the first tube body includes:

[0021] Coating the surface of the target pre-processed tube body with a high-temperature resistant coating to obtain the first tube body.

[0022] Optionally, obtaining the threaded joint by performing a second heat treatment and threading on the joint blank includes:

[0023] Heating the joint blank to a first preset heating temperature;

[0024] Cooling the joint blank heated to the first preset heating temperature to room temperature, and then heating the joint blank cooled to room temperature to a second pre-heating temperature;

[0025] Cooling the joint blank heated to the second pre-heating temperature to room temperature to obtain a to-be-processed joint;

[0026] Performing threading on the to-be-processed joint to obtain the threaded joint.

[0027] Optionally, performing threading on the to-be-processed joint to obtain the threaded joint includes:

[0028] Performing internal threading on the to-be-processed joint to obtain a first threaded joint;

[0029] Performing external threading on the to-be-processed joint to obtain a second threaded joint.

[0030] Optionally, friction press-fitting the drill pipe body and the threaded joint includes:

[0031] Friction press-fitting one end of the drill pipe body with the first threaded joint, and friction press-fitting the other end of the drill pipe body with the second threaded joint to obtain an initial drill pipe.

[0032] Optionally, the method further includes:

[0033] Annealing, quenching, and tempering the weld of the initial drill pipe to obtain the drill pipe.

[0034] A second aspect of the embodiments of the present application provides a drill pipe. The drill pipe device includes: a first threaded joint, a second threaded joint, and a drill pipe body;

[0035] One end of the drill pipe body is friction press-fitted with the first threaded joint, and the other end is friction press-fitted with the second threaded joint;

[0036] Wherein, the thread of the first threaded joint is adapted to the thread of the second threaded joint.

[0037] Advantageous effects:

[0038] The present application provides a method for manufacturing a drill pipe. The material of the drill pipe is Super 13Cr. The method includes: obtaining a drill pipe body by performing a first heat treatment on a pre-processed pipe body; obtaining a threaded joint by performing a second heat treatment and thread machining on a joint blank; friction press-fitting the drill pipe body and the threaded joint, and performing a third heat treatment on the weld after friction press-fitting to obtain the drill pipe.

[0039] The drill pipe manufactured by this method has high-strength corrosion resistance, enabling the drill pipe to be effectively used in a drilling environment containing high CO2 and Cl - to prevent problems such as drill pipe leakage and fracture caused by corrosion. Description of the Drawings

[0040] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0041] Figure 1 is a flowchart of a method for manufacturing a drill pipe provided by an embodiment of the present application;

[0042] Figure 2 is a schematic diagram of a drill pipe device provided by an embodiment of the present application. Detailed implementation manners

[0043] The following will describe the implementation manners of the present application with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. The present application can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for illustrating the present application, rather than for limiting the protection scope of the present application.

[0044] The use of drill pipes is to transport drilling mud to the drill bit and, together with the drill bit, raise, lower, or rotate the downhole device. Drill pipes must be able to withstand huge internal and external pressures, torsion, bending, and vibration. Since the polysulfonate drilling fluid added in drilling is prone to decompose to produce CO2 at high temperatures, and because CO2 dissolves in water and decomposes into HCO 3- and CO 3- , HCO 3- has extremely strong corrosiveness and will corrode ordinary drill pipes. Similarly, some Cl - will also cause corrosion to ordinary drill pipes.

[0045] In the related art, by developing low-Cr drill pipes resistant to CO2 and salt cement slurry corrosion to improve the corrosion resistance of drill pipes, but the strength of the drill pipes produced by this technology can only reach the 105 steel grade and cannot meet the requirements of ultra-deep well drilling.

[0046] In view of this, aiming at the total dry corrosion problem caused by high CO2 and Cl - due to drilling fluid or geological conditions and other drilling environments, and the serious corrosion problem will cause the drill pipe to leak and break during drilling. The embodiment of the present application proposes a manufacturing method of a drill pipe to obtain a drill pipe that can resist CO2 and Cl - corrosion with high strength.

[0047] As Figure 1 shown, Figure 1 is a flowchart of a manufacturing method of a drill pipe provided in this embodiment. The material of the drill pipe is super 13Cr, and the method includes the following steps:

[0048] S11: Obtain a drill pipe body by performing a first heat treatment on a pre-processed pipe body.

[0049] Specifically, Super 13Cr stainless steel is a martensitic stainless steel with good corrosion resistance. Super 13Cr has extremely strong corrosion resistance. Therefore, in order to better enhance the corrosion resistance of drill pipes, in this application, the prefabricated pipe bodies are all made of Super 13Cr material. The prefabricated pipe bodies made of Super 13Cr material are subjected to a first heat treatment, that is, the prefabricated pipe bodies are heated and cooled to obtain the drill pipe bodies, so as to ensure the mechanical properties of the drill pipe bodies and ensure that the drill pipes can withstand the torque of the drilling rig during the drilling process. At the same time, the obtained drill pipe bodies need to be drilled so that the drilling fluid must smoothly pass through the inner diameter of the drill pipe bodies.

[0050] S12: Obtain the threaded joint by performing a second heat treatment and threading on the joint blank.

[0051] Specifically, select a thick-walled pipe made of Super 13Cr with appropriate material and fix it on a lathe; then, use the lathe to perform machining on the thick-walled pipe to turn out the shape and dimensions of the joint blank. Then, perform a second heat treatment on the joint blank to change its internal structure and properties and obtain the required mechanical properties and hardness. The specific steps include quenching, tempering, etc. After the joint blank completes the first heat treatment and cools down to room temperature, threading can be performed on the joint blank to form the required threaded connection. This usually involves using equipment such as a threading lathe or a drill press, and according to the design requirements, machining the joint blank into a joint with specific thread specifications. Through the above steps, the thick-walled pipe can be turned out to form the joint blank, and after the second heat treatment and threading, a threaded joint with the required properties and dimensions can be obtained.

[0052] S13: Frictionally press the drill pipe body and the threaded joint, and perform a third heat treatment on the weld after the frictional pressing to obtain the drill pipe.

[0053] Specifically, frictional pressing is a connection method. The drill pipe body and the threaded joint are frictionally pressed through a frictional pressing device. During the pressing process, the frictional heat is generated between the drill pipe body and the threaded joint by the pressure and rotational force applied by the frictional pressing device to achieve the tight connection between the drill pipe body and the threaded joint. Then, perform a local third heat treatment on the weld generated after the frictional pressing. The third heat treatment includes processes such as annealing, quenching, and tempering, so as to obtain a drill pipe with good mechanical properties.

[0054] Through the manufacturing method of the drill pipe provided by this application, the obtained drill pipe can effectively be used in a drilling environment containing high CO2 and Cl - and has advantages such as preventing the drill pipe from leaking and breaking due to corrosion.

[0055] In another embodiment of this application, the obtaining of the drill pipe body by performing a first heat treatment on the prefabricated pipe body includes:

[0056] S21: Apply a high-temperature resistant coating on the surface of the pre-processed pipe body to obtain a first pipe body.

[0057] Specifically, adopt the surface decarburization prevention technology to apply a high-temperature resistant coating, such as lead phosphate powder coating, on the surface of the pre-processed pipe body to isolate the pre-processed pipe body made of super 13Cr stainless steel from contacting with the oxidation atmosphere at high temperature, which may cause oxidation and decarburization. After applying the high-temperature resistant material on the surface of the pre-processed pipe body, a first pipe body is obtained. Preferably, the high-temperature resistant coating can be customized from the manufacturer so that there is no information on the packaging to prevent information leakage.

[0058] S22: Heat the first pipe body to a preset temperature and keep it warm for a preset total duration to obtain a second pipe body.

[0059] Specifically, adopt the pulsating heat preservation technology to heat the first pipe body coated with the high-temperature resistant coating until it reaches the preset temperature. After the first pipe body is heated to the preset temperature, keep it warm for the preset total duration so that the super 13Cr material can fully undergo physical and chemical changes to achieve the required corrosion resistance, thereby obtaining a second pipe body.

[0060] S23: After the second pipe body is cooled in the air to a preset cooling temperature, place it in water to cool it to room temperature to obtain a third pipe body.

[0061] Specifically, due to the high hardenability of martensitic stainless steel, air or oil can be used as the quenching cooling medium for quenching. Therefore, the second pipe body made of super 13Cr belonging to the martensitic stainless steel material adopts the controlled cooling technology for cooling treatment. Preferably, after the pulsating heat preservation technology is completed, the second pipe body is cooled in the air for 60 - 70 s until it reaches the preset cooling temperature of 300 - 400 °C, and then the second pipe body is placed in water to continue cooling to room temperature. The purpose is to ensure the quenching cooling and improve the quenching efficiency, realizing industrial production.

[0062] S24: Heat the third pipe body to a preset tempering temperature and keep it warm for a preset tempering time. After the third pipe body is cooled in the air, the drill pipe body is obtained.

[0063] Specifically, the third pipe body that has completed cooling is further subjected to critical tempering technical treatment. Since the tempering temperature has a significant impact on the microstructure of martensitic stainless steel, different from the law that the strength of conventional drill pipe bodies decreases with the increase of the tempering temperature, tempering above the temperature at which martensitic stainless steel begins to transform into austenite will cause the refinement of martensite laths in the microstructure, and the higher the tempering temperature, the more obvious the refinement. The refinement of the microstructure will also lead to an increase in the hardness of the microstructure and an improvement in mechanical strength. During critical tempering, partial reverse austenite is produced with better strength and plasticity combination. Therefore, the third pipe body that has completed cooling is heated to 500-600 °C and held for 80-90 min to obtain the drill pipe body. Then, non-destructive testing is carried out on the obtained drill pipe body, and the defective drill pipe bodies are picked out.

[0064] Through the above surface decarburization prevention technology, pulsating heat preservation technology, controlled cooling technology and critical tempering technology, the super 13Cr of grade 110 steel is upgraded to grade 125 steel, thereby improving the strength of the drill pipe body.

[0065] In another embodiment of the present application, heating the first pipe body to a preset temperature and holding for a preset total duration to obtain the second pipe body includes:

[0066] S31: Heating the first pipe body to a preset upper limit temperature and holding for a first preset duration.

[0067] S32: After each holding for the first preset duration, heating the first pipe body to the preset lower limit temperature and holding for a second preset duration.

[0068] S33: After each holding for the second preset duration, heating the first pipe body to the preset upper limit temperature and holding for the first preset duration.

[0069] S34: When the total holding duration reaches the preset total duration, obtaining the second pipe body.

[0070] Specifically, the quenching of martensitic stainless steel is usually heated to the temperature range of 925-1065 °C. When martensite is heated to a certain temperature, it will transform into austenite. Therefore, when it is desired to achieve the highest corrosion resistance and maximum strength of the steel, the upper limit temperature of austenite should be used for heating. When good plasticity and impact toughness are desired, the lower limit temperature should be used for heating.

[0071] Therefore, the first pipe body coated with high-temperature resistant material is heated to the upper limit temperature and held for the first preset duration. After the first preset duration of holding ends, the first pipe body is heated to the lower limit temperature and held for the second preset duration. After the second preset duration ends, the first pipe body is heated to the upper limit temperature and held for the first preset duration, and so on in a cycle, so that the sum of the first preset duration and the second preset duration of holding of the first pipe body reaches the preset total duration.

[0072] Preferably, heat the first pipe body coated with the high-temperature resistant material to the upper limit temperature of 1050 - 1060 °C, keep it warm for 20 - 30 minutes, after the heat preservation time ends, heat the first pipe body to the lower limit temperature of 925 - 935 °C, keep it warm for 20 - 30 minutes, after the heat preservation ends, heat it to the upper limit temperature again, and keep it warm for 20 - 30 min, and cycle heating and heat preservation in this way, so that the total heat preservation time needs to reach 130 - 140 min.

[0073] In another embodiment of the present application, before coating the surface of the pre-processed pipe body with the high-temperature resistant coating to obtain the first pipe body, the method further includes:

[0074] S41: Thicken the pipe ends of the pre-processed pipe body to a preset size to obtain the target pre-processed pipe body.

[0075] Specifically, in order to connect with the threaded joint, the pipe ends of the drill pipe body must be thickened. Therefore, before coating the surface of the pre-processed pipe body with the high-temperature resistant coating, it is usually necessary to first thicken the pre-processed pipe body by using mechanical upsetting equipment, and during the thickening process, it is necessary to ensure that the shape and dimensional accuracy of the pipe ends meet the preset size requirements. After the thickening process, the pipe ends of the obtained target pre-processed pipe body will have higher strength and stability.

[0076] S42: Coating the surface of the pre-processed pipe body with the high-temperature resistant coating to obtain the first pipe body includes: coating the surface of the target pre-processed pipe body with the high-temperature resistant coating to obtain the first pipe body.

[0077] Specifically, coating the surface of the thickened target pre-processed pipe body with the high-temperature resistant coating can increase the high-temperature resistance performance of the first pipe body, so that the first pipe body can be used in subsequent high-temperature environments.

[0078] In another embodiment of the present application, obtaining the threaded joint by performing the second heat treatment and thread processing on the joint blank includes:

[0079] S51: Heat the joint blank to the first preset heating temperature.

[0080] S52: Cool the joint blank heated to the first preset heating temperature to room temperature, and heat the joint blank cooled to room temperature to the second preheating temperature.

[0081] S53: Cool the joint blank heated to the second preheating temperature to room temperature to obtain the joint to be processed.

[0082] S54: Perform thread processing on the joint to be processed to obtain the threaded joint.

[0083] Specifically, the thick-walled pipe is machined to turn out a blank for the joint, and then the blank for the joint is heated to a first preset heating temperature. Preferably, the first preheating temperature can be 850 - 930 °C. After being heated to the first preset heating temperature, the blank for the joint is cooled to room temperature by quenching liquid. Among them, the quenching liquid is usually a liquid with a high cooling rate, such as water and mineral oil. The quenching liquid can quickly reduce the temperature of the blank for the joint, and improve the mechanical properties and hardness of the blank for the joint by rapid cooling. After the blank for the joint is cooled to room temperature, the blank for the joint is heated again for tempering to a second preset heating temperature. Preferably, the second preheating temperature can be 540 °C - 700 °C. After being heated to the second preset heating temperature, the blank for the joint is air-cooled, and the joint to be processed is obtained after cooling to room temperature.

[0084] Then, the joint to be processed is thread-machined according to the designed dimensions, so that the threaded joint can be welded to both ends of the drill pipe body, and the threaded joint also needs to be drilled so that the drilling fluid can smoothly pass through the inner diameters of the threaded joint and the drill pipe body.

[0085] In another embodiment of the present application, thread machining is performed on the joint to be processed to obtain the threaded joint, including:

[0086] S61: Perform internal thread machining on the joint to be processed to obtain a first threaded joint.

[0087] S62: Perform external thread machining on the joint to be processed to obtain a second threaded joint.

[0088] Specifically, when performing internal thread machining on the joint to be processed, the obtained first threaded joint needs to meet the dimensional requirements for friction press-fitting with the drill pipe joint. Similarly, when performing external thread machining on the joint to be processed, the obtained second threaded joint can also be connected to the drill pipe joint. At the same time, the internal thread of the first threaded joint needs to be adapted to the external thread of the second threaded joint, so that the drill pipe can be thread-connected to the first threaded joint of another drill pipe through the second threaded joint, thereby connecting multiple drill pipes for drilling use.

[0089] In another embodiment of the present application, friction press-fitting the drill pipe body and the threaded joint includes:

[0090] S71: Friction press-fit one end of the drill pipe body with the first threaded joint, and friction press-fit the other end of the drill pipe body with the second threaded joint to obtain an initial drill pipe.

[0091] Specifically, one end of the drill pipe body is frictionally press-fitted with the first threaded joint to connect the drill pipe body and the first threaded joint, and then the other end of the drill pipe body is frictionally press-fitted with the second threaded joint, so that the two ends of the drill pipe joint are respectively connected to the first threaded joint and the second threaded joint, thereby obtaining an initial drill pipe.

[0092] In another embodiment of the present application, the method further includes:

[0093] S81: Annealing, quenching, and tempering the weld of the initial drill pipe to obtain the drill pipe.

[0094] Specifically, the initial drill pipe with a weld formed by friction press-fitting is annealed, that is, a local area of the weld is heated and held for a period of time, and then the initial drill pipe is cooled. The purpose is to eliminate internal stress and improve the plasticity and toughness of the initial drill pipe. Then the annealed initial drill pipe is quenched, that is, the initial drill pipe is heated to a certain temperature and held for a period of time, aiming to improve the hardness and wear resistance of the initial drill pipe. Finally, the quenched initial drill pipe is tempered, that is, the initial drill pipe is heated to a certain temperature and held for a period of time. Finally, after the initial drill pipe is cooled to room temperature, the drill pipe is obtained.

[0095] In the second aspect of the present application, a drill pipe is provided, as Figure 2 shown in a schematic diagram of a drill pipe device. The drill pipe device includes: a first threaded joint, a second threaded joint, and a drill pipe body; one end of the drill pipe body is frictionally press-fitted with the first threaded joint, and the other end is frictionally press-fitted with the second threaded joint; wherein, the threads of the first threaded joint are adapted to the threads of the second threaded joint.

[0096] Specifically, the first threaded joint is obtained by machining internal threads on a blank joint, and the second threaded joint is obtained by machining external threads on a blank joint. The first threaded joint is frictionally press-fitted with one end of the drill pipe body, so that the first threaded joint is welded to the drill pipe body, and then the second threaded joint is also frictionally press-fitted with the other end of the drill pipe body, so that the second threaded joint is welded to the drill pipe body. Among them, the internal threads of the first threaded joint are adapted to the external threads of the second threaded joint, so that the drill pipe can be connected to another drill pipe through internal and external threads, and the length after connecting the drill pipes can be selected according to the depth of the well.

[0097] In addition, the drill pipe obtained in the above embodiment was tested for components in mass percentage, and the results were: C: 0.02%, Si: 0.31%, Mn: 0.34%, P: 0.012%, S: 0.001%, Ni: 5.3%, Cr: 13.18%, Mo: 0.96%, Cu: 0.04%, Al: 0.034%, V: 0.08%, Pb: 0.0001%, Sn: 0.0016%, As: 0.0015%, Bi: 0.0005%, Nb: 0.02%, N: 0.0258%.

[0098] The present application also conducted a mechanical property test on the drill pipe body obtained by the drill pipe manufacturing method provided by the present application, and obtained a drill pipe mechanical property test table:

[0099] Table 1:

[0100]

[0101] Among them, under the condition of 21℃, the drill pipe body was sampled with a size of 10×10mm and tested, and the yield strength of the test was 905 MPa. The yield strength is the yield limit of the metal material when the yield phenomenon occurs, that is, the stress to resist the micro plastic deformation. The tensile strength is 953 MPa. The tensile strength is the critical value of the transition from uniform plastic deformation to local concentrated plastic deformation of the metal, and it is also the maximum bearing capacity of the metal under static tension. The elongation after fracture is 17%. The elongation after fracture is the percentage of the elongation length of the test rod to the original length when the metal material is broken by external force (tension). The end face shrinkage is 45%. The end face shrinkage is the degree of cross-section reduction of the steel during the cooling process, which is one of the important indicators of steel performance. The impact absorption work of the three samples was 188 / 144 / 178 joules respectively. The impact absorption work refers to the ability of an object to absorb plastic deformation work and fracture work under the action of impact load.

[0102] Therefore, it can be seen from the test data obtained above that the drill pipe body obtained by the drill pipe manufacturing method provided in the present application has good tensile strength and yield strength performance, and can meet the conditions for the drill pipe to work underground.

[0103] At the same time, the corrosion resistance of the drill pipe was tested at 140°C. - Under the condition of 25000mg / L and the test time of 168h, the corrosion rate of the drill pipe of the present application is ≤0.06mm / a; while under the same conditions, the corrosion rate of the ordinary drill pipe is 0.95mm / a. Therefore, the corrosion resistance and strength of the drill pipe obtained by the drill pipe manufacturing method provided by the present application are significantly better than those of the ordinary strength drill pipe.

[0104] To better illustrate the present application, the present application also provides the following specific examples:

[0105] Select a pre-processed pipe body made of Super 13Cr. Using a mechanical upsetting forging device, thicken the pipe end to obtain a target pre-processed pipe body, so that the thickened pipe end meets the welding requirements of the threaded joint. Then coat the surface of the target pre-processed pipe body with a high-temperature resistant coating, so that the obtained first pipe body can work at high temperatures and avoid oxidation decarburization caused by contact with the oxidation atmosphere; then heat the first pipe body to the upper limit temperature of 1050 °C, and keep it warm for 25 minutes. After the insulation time ends, heat the first pipe body to the lower limit temperature of 925 °C, and keep it warm for 26 minutes. After the insulation ends, heat it to the upper limit temperature again and keep it warm for 25 min. Heat and keep warm in this cycle, so that the total insulation time needs to reach 130 min to obtain a second pipe body; then cool the second pipe body in the air for 60 s until it cools down to the preset cooling temperature of 300 °C, and then place the second pipe body in water and continue to cool it to room temperature to obtain a third pipe body; then heat the third pipe body to 500 °C and keep it warm for 80 min to obtain a drill pipe body. Finally, perform non-destructive testing on the obtained drill pipe body, and pick out the defective drill pipe bodies.

[0106] Select a thick-walled pipe made of the same material Super 13Cr, perform turning on it to machine the shape and size of the joint blank, then heat the joint blank to 850 °C, and then cool the joint blank to room temperature through quenching liquid. Then heat the joint blank for tempering to 540 °C, and perform air cooling treatment on the joint blank. After cooling to room temperature, obtain the joint to be processed. Perform thread machining on the obtained joint to be processed according to the size, perform internal thread machining on the joint to be processed to obtain a first threaded joint, and perform external thread machining to obtain a second threaded joint.

[0107] Perform friction press fitting on the drill pipe body with the first threaded joint and the second threaded joint, so that the drill pipe body is connected with the first threaded joint and the second threaded joint to obtain an initial drill pipe; then perform annealing treatment, quenching treatment and tempering treatment on the weld of the initial drill pipe to obtain a drill pipe.

[0108] Each embodiment in this specification is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other.

[0109] Although the preferred embodiments of the embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments and all changes and modifications falling within the scope of the embodiments of the present application.

[0110] In the description of this specification, the descriptions with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0111] Furthermore, the term "comprising", "including", or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements that are inherent to such process, method, article, or terminal device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article, or terminal device comprising the element. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0112] It should also be noted that in this article, the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0113] The above has introduced in detail a manufacturing method of a drill pipe and a drill pipe device provided by the present application. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only for helping to understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A manufacturing method of a drill pipe, characterized in that, The material of the drill pipe is super 13Cr, and the method includes: Obtaining a drill pipe body by performing a first heat treatment on a pre-processed pipe body; Obtaining a threaded joint by performing a second heat treatment and threading on a joint blank; Frictionally press-connecting the drill pipe body and the threaded joint, and performing a third heat treatment on the weld after the frictional press-connection to obtain the drill pipe.

2. The manufacturing method of the drill pipe according to claim 1, characterized in that, The obtaining of the drill pipe body by performing a first heat treatment on the pre-processed pipe body includes: Coating a high-temperature resistant coating on the surface of the pre-processed pipe body to obtain a first pipe body; Heating the first pipe body to a preset temperature and holding for a preset total duration to obtain a second pipe body; After cooling the second pipe body in the air to a preset cooling temperature, placing it in water to cool to room temperature to obtain a third pipe body; Heating the third pipe body to a preset tempering temperature and holding for a preset tempering time, and after the third pipe body cools in the air, obtaining the drill pipe body.

3. The manufacturing method of the drill pipe according to claim 2, characterized in that, The heating of the first pipe body to a preset temperature and holding for a preset total duration to obtain a second pipe body includes: Heating the first pipe body to a preset upper limit temperature and holding for a first preset duration; After each holding for the first preset duration, heating the first pipe body to the preset lower limit temperature and holding for a second preset duration; After each holding for the second preset duration, heating the first pipe body to the preset upper limit temperature and holding for a first preset duration; When the total holding duration is the preset total duration, obtaining the second pipe body.

4. The manufacturing method of the drill pipe according to claim 2, characterized in that, Before coating the high-temperature resistant coating on the surface of the pre-processed pipe body to obtain the first pipe body, the method further includes: Thickening the pipe ends of the pre-processed pipe body to a preset size to obtain a target pre-processed pipe body; The coating of the high-temperature resistant coating on the surface of the pre-processed pipe body to obtain the first pipe body includes: Coating a high-temperature resistant coating on the surface of the target pre-processed pipe body to obtain the first pipe body.

5. The manufacturing method of the drill pipe according to claim 1, characterized in that The obtaining of the threaded joint by performing a second heat treatment and threading on the joint blank includes: Heating the joint blank to a first preset heating temperature; Cooling the joint blank heated to the first preset heating temperature to room temperature, and heating the joint blank cooled to room temperature to a second pre-heating temperature; Cooling the joint blank heated to the second pre-heating temperature to room temperature to obtain a joint to be processed; Performing threading on the joint to be processed to obtain the threaded joint.

6. The manufacturing method of the drill pipe according to claim 5, characterized in that, The performing of threading on the joint to be processed to obtain the threaded joint includes: Performing internal threading on the joint to be processed to obtain a first threaded joint; Performing external threading on the joint to be processed to obtain a second threaded joint.

7. The manufacturing method of the drill pipe according to claim 6, characterized in that, The frictionally press-connecting of the drill pipe body and the threaded joint includes: Frictionally press-connecting one end of the drill pipe body with the first threaded joint, and frictionally press-connecting the other end of the drill pipe body with the second threaded joint to obtain an initial drill pipe.

8. The manufacturing method of the drill pipe according to claim 7, characterized in that, The method further includes: Performing annealing treatment, quenching treatment and tempering treatment on the weld of the initial drill pipe to obtain the drill pipe.

9. A drill pipe device, characterized in that, The drill pipe device includes: a first threaded joint, a second threaded joint and a drill pipe body; One end of the drill pipe body is frictionally press-fitted with the first threaded joint, and the other end is frictionally press-fitted with the second threaded joint; Wherein, the threads of the first threaded joint are adapted to the threads of the second threaded joint.

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