Torsion-resistant drill rod joint and design method of drill rod joint

Abstract

The invention provides a torsion-resistant drill rod joint and a design method of the drill rod joint, the drill rod joint comprises a male joint and a female joint, and the outer surface of the male joint and the inner surface of the female joint are a first conical connecting surface and a second conical connecting surface respectively; external threads and internal threads are arranged on the first conical connecting surface and the second conical connecting surface; the male joint and the female joint matched with the male joint as well as the female joint and the male joint matched with the female joint respectively correspond to a buckle type, each buckle type has the number of upper buckle circles and torsional strength within a set range, the set range of the number of the upper buckle circles is 5-13 circles, and the set range of the torsional strength is not smaller than 10000 ft-lbs. By means of the design of the coaxial conical connecting face and the cooperation with the accurately-set number of upper buckling circles and the torsional strength range, the structure and the mechanical property of the connector are optimized, it is guaranteed that under the complex and severe drilling working condition, the drill rod connector can efficiently, stably and safely transmit torque, the fault occurrence rate is reduced, and the overall drilling operation efficiency is improved.

Description

Technical Field

[0001] The invention relates to the field of drilling tools, and in particular to a torsion-resistant drill pipe joint and a drill pipe joint design method. Background Art

[0002] In the field of exploration and exploitation of resources such as oil and natural gas, drill pipe, as a key component of the drilling system, undertakes important missions such as transmitting torque, conveying drilling fluid and supporting the weight of drill tools. The performance of its joints is directly related to the safety, efficiency and cost control of the entire drilling operation.

[0003] Traditional drill pipe joint designs have gradually exposed many limitations when dealing with complex and changeable downhole working conditions. On the one hand, early drill pipe joints often used simple cone connections with threaded structures. This connection method has significant stress concentration when subjected to high torque.

[0004] As drilling technology expands to deeper and more complex geological structures, stringent requirements are placed on the torsional performance of drill pipe joints. The complex geological environment underground, such as the high resistance brought by hard rock formations and the irregular stress caused by formation creep applied to the drill pipe, all test the torsional stability of the joints. Today, the torsional strength of conventional drill pipe joints is often difficult to match the growing operational needs. A large number of joints fail because they cannot withstand torque before reaching the expected drilling depth, which not only causes the loss of equipment such as drill pipes, but also wastes a lot of manpower and material resources due to frequent replacement of joints during drilling.

[0005] Furthermore, the make-up speed accounts for a large proportion of the non-working time during the tripping and drilling process of the drilling platform. Therefore, studying the relationship between the various parameters of the thread structure and the make-up speed is of great significance to improving the working efficiency of the drilling platform and reducing the non-working time (NPT). If the number of make-up turns is too small, the thread engagement between the joints is insufficient, and it is very easy to loosen and disengage under the action of torque, causing drilling safety accidents; and if the number of make-up turns is too large, the non-working time (NPT) is increased, thus affecting the working efficiency.

[0006] In addition, during the long-term rotation and vibration of the drill pipe, even small connection defects or performance shortcomings will accumulate and magnify over time. If the thread types of different drill pipe joints do not have standardized and suitable threading circles and torsional strength ranges, it will aggravate the wear of the connection parts, seal failure and other problems, leading to drilling fluid leakage, affecting the normal operation of the drilling fluid circulation system, and further endangering the stability and safety of downhole operations. Summary of the invention

[0007] The purpose of the present invention is to provide a torsion-resistant drill pipe joint and a drill pipe joint design method. By studying the relationship between various parameters of the thread structure and the make-up speed, the non-working time (NPT) can be reduced and the working efficiency of the drilling platform can be improved. At the same time, the drill pipe joint also has good torsion strength.

[0008] The embodiment of the present invention is achieved as follows: In a first aspect, a torsion-resistant drill pipe joint according to an embodiment of the present application comprises a male joint and a female joint respectively arranged at two ends of the drill pipe, the male joint and the female joint are coaxially arranged, the outer surface of the male joint and the inner surface of the female joint are respectively a first tapered connection surface and a second tapered connection surface, and the first tapered connection surface and the second tapered connection surface have the same inclination; the first tapered connection surface and the second tapered connection surface are respectively provided with an external thread and an internal thread, the external thread is used for threaded connection with the second tapered connection surface of the female joint of the first drill pipe matched therewith, and the internal thread is used for threaded connection with the first tapered connection surface of the male joint of the second drill pipe matched therewith; The male connector and the female connector that match it, and the female connector and the male connector that match it correspond to a buckle type, each of the buckle types is determined by the thread parameters of the male connector and the corresponding female connector, each of the buckle types has a set range of buckle turns and a set range of torsional strength, the set range of the buckle turns is 5 turns to 13 turns, and the set range of torsional strength is not less than 10000 ft-lbs; the buckle turns and the thread parameters also satisfy the following relationship: ; Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

[0009] In a possible implementation, the thread parameters of the male connector and the female connector include a root arc radius, and the root arc radius of each of the male connector and the female connector in any thread type ranges from 0.038 in to 0.08 in.

[0010] In a possible implementation, the thread parameters of the male connector and the female connector further include a thread profile half angle, and the thread profile half angle of each of the male connector and the female connector in any thread type ranges from 27.5° to 44.5°.

[0011] In a possible implementation, the thread parameters of the male connector and the female connector further include a taper, and the taper of each of the male connector and the female connector in any thread type ranges from 1 / 16 to 1 / 6.

[0012] In a possible implementation, when the buckle type is a designed buckle type, the taper and the tooth bottom arc radius also satisfy the following corresponding relationship: when the taper is 1 / 16, the corresponding tooth bottom arc radius range is 0.05in~0.065in; when the taper is 1 / 12, the corresponding tooth bottom arc radius range is 0.04in~0.060in; when the taper is 1 / 10, the corresponding tooth bottom arc radius range is 0.045in~0.055in.

[0013] In a possible implementation, the thread parameters of the male connector and the female connector further include a pitch, and the pitch of each of the male connector and the female connector in any thread type ranges from 0.250 in to 0.364 in.

[0014] In a possible implementation manner, the partial derivative of the number of make-up turns and the taper satisfies the following relationship: ; Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

[0015] In a possible implementation manner, the partial derivative of the number of thread-up turns and the radius of the tooth bottom arc satisfies the following relationship: ; Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

[0016] In a possible implementation manner, the derivation of the number of make-up turns and the pitch satisfies the following relationship: ; Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

[0017] In a possible implementation manner, the tooth bottom arc radius, the thread pitch, the tooth profile half angle and the taper satisfy the following relationship: ; Where θ is the tooth profile half angle, tpr is the taper, P is the pitch, R is the tooth bottom arc radius, and Rmax is the maximum value of the tooth bottom arc radius.

[0018] In a second aspect, a torsion-resistant drill pipe joint according to an embodiment of the present application comprises a male joint and a female joint respectively arranged at both ends of the drill pipe, the male joint and the female joint are coaxially arranged, the outer surface of the male joint and the inner surface of the female joint are respectively a first tapered connection surface and a second tapered connection surface, and the first tapered connection surface and the second tapered connection surface have the same inclination; the first tapered connection surface and the second tapered connection surface are respectively provided with an external thread and an internal thread, the external thread is used for threaded connection with the second tapered connection surface of the female joint of the first drill pipe matched therewith, and the internal thread is used for threaded connection with the first tapered connection surface of the male joint of the second drill pipe matched therewith; The male connector and the female connector matched therewith and the female connector and the male connector matched therewith respectively correspond to a buckle type, each buckle type has a set range of buckle turns, each buckle type is determined by the thread parameters of the male connector and the female connector, and the thread parameters of the male connector and the female connector include the tooth bottom arc radius, the tooth profile half angle, the taper and the pitch; the number of buckle turns and the tooth bottom arc radius, the tooth profile half angle, the taper and the pitch satisfy the following relationship: ; Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

[0019] In a possible implementation manner, the partial derivative of the number of make-up turns and the taper satisfies the following relationship: ; Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

[0020] In a possible implementation manner, the partial derivative of the number of thread-up turns and the radius of the tooth bottom arc satisfies the following relationship: ; Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

[0021] In a possible implementation manner, the derivation of the number of make-up turns and the pitch satisfies the following relationship: ; Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

[0022] In a possible implementation manner, the tooth bottom arc radius, the thread pitch, the tooth profile half angle and the taper satisfy the following relationship: ; Where θ is the tooth profile half angle, tpr is the taper, P is the pitch, R is the tooth bottom arc radius, and Rmax is the maximum value of the tooth bottom arc radius.

[0023] In a possible implementation, each of the buckle types has a set range of buckle turns and a set range of torsional strength, the set range of the buckle turns is 5 turns to 13 turns, and the set range of torsional strength is not less than 10,000 ft-lbs.

[0024] In a possible implementation, the radius of the thread bottom arc of each of the male connector and the female connector in any buckle type is in the range of 0.038 in-0.08 in.

[0025] In a possible implementation, the thread profile half angle of each of the male connector and the female connector in any buckle type ranges from 27.5° to 44.5°.

[0026] In a possible implementation, the taper of each of the male connector and the female connector in any buckle type ranges from 1 / 16 to 1 / 6.

[0027] In a possible implementation, when the buckle type is a designed buckle type, the taper and the tooth bottom arc radius also satisfy the following corresponding relationship: when the taper is 1 / 16, the corresponding tooth bottom arc radius range is 0.05in~0.065in; when the taper is 1 / 12, the corresponding tooth bottom arc radius range is 0.04in~0.060in; when the taper is 1 / 10, the corresponding tooth bottom arc radius range is 0.045in~0.055in.

[0028] In a possible embodiment, the pitch of each of the male connector and the female connector in any buckle type ranges from 0.250 in to 0.364 in.

[0029] In a third aspect, a drill pipe joint design method according to an embodiment of the present application comprises: Determine the setting range of the number of beading turns and the torsional strength of the designed buckle type according to the number of beading turns and the torsional strength of the standard buckle type and the special buckle type respectively; wherein the setting range corresponding to the number of beading turns of the designed buckle type is 5 turns to 13 turns, and the setting range corresponding to the torsional strength of the designed buckle type is not less than 10000 ft-lbs; Set the thread parameters in the designed thread type, which include the tooth bottom arc radius, taper, tooth profile half angle and pitch. The tooth profile radius and pitch are selected according to the number of beading turns and the range of torsional strength; The taper range of the series is selected according to the number of make-up circles and the range of torsional strength; According to the relationship between the thread parameters and the number of make-up turns, a series range of tooth bottom arc radii corresponding to the taper range is obtained.

[0030] In a possible implementation manner, the number of thread turns, the tooth bottom arc radius, the tooth profile half angle, the taper and the thread pitch satisfy the following relationship: ; Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

[0031] In a possible implementation manner, the taper and the tooth bottom arc radius also satisfy the following corresponding relationship: when the taper is 1 / 16, the corresponding tooth bottom arc radius range is 0.05in~0.065in; when the taper is 1 / 12, the corresponding tooth bottom arc radius range is 0.04in~0.060in; when the taper is 1 / 10, the corresponding tooth bottom arc radius range is 0.045in~0.055in.

[0032] The beneficial effects of the embodiments of the present invention are as follows: the present invention optimizes the joint structure and mechanical properties through a unique coaxial tapered connection surface design, with a precisely set number of make-up circles (5-13 circles) and a torsional strength range of not less than 10,000 ft-lbs, to ensure that the drill pipe joint can efficiently, stably and safely transmit torque under complex and harsh drilling conditions, reduce the occurrence of failures, and improve the overall drilling operation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 A cross-sectional view of a male joint in a torsion-resistant drill pipe joint according to an embodiment of the present invention along the axial direction; Figure 2 It is a cross-sectional view of a female joint in a torsion-resistant drill pipe joint according to an embodiment of the present invention along the axial direction; Figure 3 A diagram showing the relationship between the number of make-up circles and the thread half angle in a torsion-resistant drill pipe joint according to an embodiment of the present invention; Figure 4 A diagram showing the relationship between the number of make-up circles and the taper in a torsion-resistant drill pipe joint according to an embodiment of the present invention; Figure 5A diagram showing the relationship between the number of thread-bottom arc radius and the number of thread-bottom circles in a torsion-resistant drill pipe joint according to an embodiment of the present invention; Figure 6 A diagram showing the relationship between the number of make-up circles and the thread pitch in a torsion-resistant drill pipe joint according to an embodiment of the present invention; Figure 7 The figure is a relationship diagram between the number of make-up circles, the taper, and the radius of the thread bottom arc in a torsion-resistant drill pipe joint according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. 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.

[0037] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0038] like Figure 1 and Figure 2 As shown, Figure 1 is the cross-sectional view of the male connector along the axial direction. Figure 2 It is a cross-sectional view of the female joint along the axial direction. A torsion-resistant drill pipe joint of an embodiment of the present application includes a male joint and a female joint respectively arranged at both ends of the drill pipe, the male joint and the female joint are coaxially arranged, the outer surface of the male joint and the inner surface of the female joint are respectively a first conical connecting surface and a second conical connecting surface, and the inclinations of the first conical connecting surface and the second conical connecting surface are the same; the first conical connecting surface and the second conical connecting surface are respectively provided with an external thread and an internal thread, the external thread is used for threaded connection with the second conical connecting surface of the female joint of the first drill pipe matched therewith, and the internal thread is used for threaded connection with the first conical connecting surface of the male joint of the second drill pipe matched therewith; the male joint and the female joint matched therewith and the female joint and the male joint matched therewith correspond to a buckle type, each buckle type has a set range of buckle turns and a set range of torsional strength, the setting range of the buckle turns is 5 turns-13 turns, and the setting range of torsional strength is not less than 10000ft-lbs.

[0039] The number of make-up turns determines the make-up speed of the drill pipe that cooperates with each other. Generally speaking, the larger the number of make-up turns, the slower the make-up speed, and the smaller the number of make-up turns, the faster the make-up speed. The speed of make-up determines the proportion of non-working time during the drilling platform's tripping and drilling work. The faster the make-up speed, the smaller the non-working time (NTP, that is, the time occupied by the make-up process), which is equivalent to increasing the actual working time of the drill pipe and improving work efficiency. The faster the make-up speed means a smaller number of make-up turns, and a smaller number of make-up turns may cause the male and female joints to fail to fully cooperate, affecting the connection stability of the male and female joints.

[0040] In addition, the torsional strength of the drill pipe joint determines the maximum stress value that the male and female joints can withstand when subjected to torque, which directly reflects the stability and durability of the male and female joints when subjected to torsion. The higher the torsional strength, the stronger the torsion resistance of the material during torsion deformation, which means that the male and female joints are more solid and durable. At the same time, the higher the torsional strength, the faster the construction speed. Since the drill bit can withstand a greater torque, it can pass through the formation faster, improve the drilling speed and efficiency, and reduce the incidence of drill pipe stuck, thereby improving construction efficiency. Through the coaxial tapered connection surface design, with the precisely set number of buckle circles (5-13 circles) and the torsional strength range of not less than 10000ft-lbs, the joint structure and mechanical properties are optimized to ensure that the drill pipe joint can efficiently, stably and safely transmit torque under complex and harsh drilling conditions, reduce the occurrence of failures, and improve the overall drilling operation efficiency.

[0041] In some embodiments, each buckle type is determined by the thread parameters of the male connector and the corresponding female connector. The thread parameters of the male connector and the female connector include the radius of the tooth bottom arc. The range of the radius of the tooth bottom arc of each male connector and the female connector in any buckle type is 0.038in-0.08in. In this way, the contact stress distribution of the thread teeth in the axial and circumferential directions can be more uniform. It can withstand the complex alternating loads generated from the marine environment and the drilling operation process, can effectively reduce the stress concentration at the root of the thread, reduce the generation and expansion of fatigue cracks, and ensure the long-term reliability of the drill pipe connection under harsh working conditions.

[0042] In some embodiments, the thread parameters of the male and female connectors also include a thread profile half angle, and the thread profile half angle of each male and female connector in any thread type ranges from 27.5° to 44.5°. The thread profile half angle in this range ensures that when the thread is subjected to internal pressure, each thread tooth shares the load evenly, avoiding damage to individual thread teeth due to local stress concentration, thereby significantly improving the overall reliability and sealing of the connection, effectively preventing medium leakage, and ensuring the safe and stable operation of the pipeline system.

[0043] In some embodiments, the thread parameters of the male and female connectors also include a taper, and the taper range of each male and female connector in any thread type is 1 / 16 - 1 / 6. In this way, the male and female connectors can gradually achieve a close fit during the tightening process, especially forming a reliable sealing contact at the sealing surface. As the threading proceeds, the contact pressure between the threads and the sealing surface increases evenly, maximizing the threading speed and efficiency between the male and female connectors.

[0044] In some embodiments, when the buckle type is a design buckle type, the taper and the tooth bottom arc radius also satisfy the following corresponding relationship: when the taper is 1 / 16, the corresponding tooth bottom arc radius ranges from 0.05in to 0.065in; when the taper is 1 / 12, the corresponding tooth bottom arc radius ranges from 0.04in to 0.060in; when the taper is 1 / 10, the corresponding tooth bottom arc radius ranges from 0.045in to 0.055in. This makes the stress distribution of the threaded connection more uniform and reasonable, effectively reduces stress concentration, and enhances the bearing capacity and fatigue resistance of the connection, so that it can cope with a variety of complex loads.

[0045] In some embodiments, the thread parameters of the male and female connectors also include pitch, and the pitch of each male and female connector in any buckle type ranges from 0.250in to 0.364in. This enables the force distribution of the male and female connectors to be more uniform when subjected to huge tensile forces. Compared with pitches that are too dense or too sparse, within this range, each circle of thread can effectively share the load, reduce stress concentration, and prevent deformation or damage of the thread due to excessive local force.

[0046] In some embodiments, the number of make-up turns and the thread parameters satisfy the following relationship: ; In the formula, N is the number of make-up turns, θ is the tooth profile half angle, tpr is the taper, P is the pitch, and R is the tooth bottom arc radius. The number of make-up turns can be accurately calculated through the selected thread parameters, so that the mechanical properties of the threaded connection can be optimized. For example, when the tooth profile half angle, taper, pitch and tooth bottom arc radius are determined according to the design, the number of make-up turns obtained by this relationship can ensure that the stress distribution of the thread is uniform when transmitting huge torque and axial force, avoiding the occurrence of fatigue cracks caused by local stress concentration, thereby significantly improving the fatigue life and reliability of the connection.

[0047] In some embodiments, the partial derivative of the number of make-up turns and the taper satisfies the following relationship: ; Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius. Figure 4 , Figure 4This is a relationship diagram between the number of make-up turns and the taper in a torsion-resistant drill pipe joint in an embodiment of the present invention. In the figure, the horizontal axis represents the taper and the vertical axis represents the number of make-up turns (in turns). It can be seen from the figure that when the other thread parameters are fixed, the number of make-up turns is negatively correlated with the taper. Therefore, the change in the number of make-up turns can be accurately controlled by making slight adjustments to the taper, thereby obtaining the relationship change trend between the number of make-up turns and the taper, and providing a theoretical reference for the thread design of male and female joints.

[0048] In some embodiments, reference Figure 4 When the taper is 1 / 10, the corresponding number of beading turns is 7.01, compared with 1 / 16, the corresponding number of beading turns is 11.8, which can significantly reduce the number of beading turns and reduce non-working time (NPT), thereby improving work efficiency. Compared with 1 / 6 taper, the corresponding number of beading turns is 4.2, and the male and female joints can be fully connected, thereby improving the connection and sealing performance between the male and female joints.

[0049] In some embodiments, the partial derivative of the number of thread turns and the radius of the tooth bottom arc satisfies the following relationship: ; Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius. Figure 5 , Figure 5 1 is a graph showing the relationship between the number of thread-bottom arc radius and the thread-bottom arc radius in a torsion-resistant drill pipe joint according to an embodiment of the present invention. In the graph, the abscissa represents the thread-bottom arc radius (in units of ), the ordinate represents the number of make-up turns (in turns). It can be seen from the figure that, when the other thread parameters are fixed, the number of make-up turns is negatively correlated with the radius of the tooth bottom arc. Therefore, the change in the number of make-up turns can be accurately controlled by slightly adjusting the radius of the tooth bottom arc, thereby obtaining the changing trend of the relationship between the number of make-up turns and the tooth bottom arc radius, and providing a theoretical reference for the design of male and female joint threads.

[0050] In some embodiments, reference Figure 5 , when the radius of the tooth bottom arc is 1.27 When the taper is 0.10, the corresponding number of turns is 7.01, or when the taper is 0.10, the corresponding number of turns is 8.9, compared with the tooth bottom arc radius of 2.1 , the corresponding number of buckle circles is 1.6 circles, and the male and female joints can be fully connected, thereby improving the connection sealing performance between the male and female joints.

[0051] In some embodiments, the derivative of the number of make-up turns and the pitch satisfies the following relationship: ; Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius. Figure 6 , Figure 6 : is a relationship diagram between the number of make-up circles and the pitch in a torsion-resistant drill pipe joint according to an embodiment of the present invention. In the figure, the abscissa represents the pitch (in units of ), the ordinate represents the number of make-up turns (in turns). It can be seen from the figure that, when the other thread parameters are fixed, the number of make-up turns is positively correlated with the pitch. Therefore, the change in the number of make-up turns can be accurately controlled by making slight adjustments to the pitch, thereby obtaining the changing trend of the relationship between the number of make-up turns and the pitch, and providing a theoretical reference for the design of male and female joint threads.

[0052] In some embodiments, reference Figure 6 , when the pitch is 7.257 When the thread pitch is 6.35, the corresponding number of turns is 7.01. , the corresponding number of turns is 6.06, or when the pitch is 10.16 , the corresponding number of make-up circles is 8.92 circles, which can significantly reduce the number of make-up circles and reduce the non-working time (NPT), thereby improving work efficiency.

[0053] In some embodiments, reference Figure 3 , Figure 3 : This is a relationship diagram between the number of beading circles and the thread profile half angle in a torsion-resistant drill pipe joint according to an embodiment of the present invention. In this figure, the horizontal axis represents the thread profile half angle (in degrees), and the vertical axis represents the number of beading circles (in circles). Figure 3 It can be seen that there is a negative correlation between the number of make-up circles and the tooth profile half angle, that is, as the tooth profile half angle increases, the number of make-up circles decreases accordingly.

[0054] In some embodiments, when the tooth profile half angle is 30°, the corresponding number of bends is 8.0, when the tooth profile half angle is 35°, the corresponding number of bends is 7.0, and when the tooth profile half angle is 45°, the corresponding number of bends is 5.6. This can significantly reduce the number of bends and the non-working time (NPT), thereby improving work efficiency.

[0055] In some embodiments, reference Figure 7 , Figure 7 The figure is a relationship diagram between the number of beading circles, taper, and arc radius of the tooth bottom in a torsion-resistant drill pipe joint according to an embodiment of the present invention. The coordinate in the X direction in the figure represents the arc radius R of the tooth bottom (in units of ), the Y-axis coordinate represents the taper tpr, and the vertical coordinate represents the number of turns (turns). Figure 7It can be seen that the influence trend of the two parameter variables of taper and tooth bottom arc radius on the number of make-up turns shows that compared with taper, the tooth bottom arc radius has a greater influence on the number of make-up turns. When adjusting the thread parameters to obtain the corresponding number of make-up turns, the degree of adjustment of the tooth bottom arc and taper (other parameters remain unchanged) can be controlled according to design requirements to obtain different numbers of make-up turns. For example, when it is necessary to quickly adjust the number of make-up turns, it is possible to consider increasing the degree of adjustment of the tooth bottom arc radius within a reasonable range, so as to achieve rapid adjustment of the number of make-up turns.

[0056] In some embodiments, the tooth bottom arc radius and the pitch, tooth profile half angle and taper satisfy the following relationship: ; In the formula, θ is the tooth profile half angle, tpr is the taper, P is the pitch, R is the tooth bottom arc radius, and Rmax is the maximum value of the tooth bottom arc radius. After determining the pitch, tooth profile half angle and taper according to the design requirements, the tooth bottom arc radius is calculated through this relationship, and the stress distribution and deformation of the connection under complex loads are predicted accordingly, which improves the stability of the male and female joint connection.

[0057] In some embodiments, the two ends of the drill pipe are respectively connected to the other two drill pipes (the first drill pipe and the second drill pipe) that match it. For example, the male joint of the drill pipe is connected to the female joint of the first drill pipe to form buckle type 1, and the female joint of the drill pipe is connected to the male joint of the second drill pipe to form buckle type 2. Buckle type 1 and buckle type 2 can be the same buckle type or different buckle types, and can be selected according to the specific working environment. For example, it is used in the deepwater and ultra-deepwater oil and gas development in the Gulf of Mexico, and in the deep wells, ultra-deep wells (6000 meters deep) and large displacement drilling in the North American land market. The main requirements of the well conditions for the performance of the drill pipe joint are good fatigue performance, operating efficiency and low repair rate, etc., so it is necessary to select a buckle type with a small number of buckle turns and appropriate torsional strength. For example, the number of buckle turns can be selected to be about 9, and the corresponding torsional strength can be selected to be about 35000ft-lbs. Such a buckle type has a fast buckle speed (smaller NTP) and also has good torsional strength, which can meet the use requirements of ultra-deep wells.

[0058] In some embodiments, the drill rod in this embodiment includes multiple designed buckle types (buckle type 01, buckle type 02, buckle type 03, buckle type 04, buckle type 05, buckle type 06, buckle type 07, buckle type 08, buckle type 09, buckle type 10, buckle type 11, buckle type 12, buckle type 13, etc.), and the multiple designed buckle types share a range of the number of buckle turns, that is, the number of buckle turns of each buckle type ranges from 5 turns to 13 turns. The torsional strength of each of the above-mentioned multiple buckle types corresponds to a minimum torsional strength, and the minimum torsional strength of each buckle type is less than the set range of torsional strength (10000ft-lbs).

[0059] In some embodiments, the ranges of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of turns (turns) and torsional strength (ft-lbs) of button type 01 are: 3 1 / 9-3 1 / 7, 1 1 / 3-1 2 / 3, 1:9-1:7, 0.04-0.06, 5-6, 11000-13000, respectively.

[0060] As a preferred embodiment, referring to Table 1, the values ​​of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of upper turns (turns) and torsional strength (ft-lbs) of buckle type 01 are: 3 1 / 8, 1 1 / 2, 1:8, 0.05, 5, 12000 respectively.

[0061] In some embodiments, the ranges of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of turns (turns) and torsional strength (ft-lbs) of the button type 02 are: 3 1 / 3-3 3 / 7, 1 3 / 8-1 7 / 8, 1:9-1:7, 0.04-0.06, 5-6, 14000-16000, respectively.

[0062] As a preferred embodiment, referring to Table 1, the values ​​of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of upper turns (turns) and torsional strength (ft-lbs) of buckle type 02 are: 3 3 / 8, 1 5 / 8, 1:8, 0.05, 5, 15000 respectively.

[0063] In some embodiments, the ranges of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of turns (turns) and torsional strength (ft-lbs) of button type 03 are: 3 2 / 3-4 1 / 4, 1 2 / 3-2 1 / 3, 1:11-1:9, 0.04-0.06, 7-9, 20000-24000, respectively.

[0064] As a preferred embodiment, referring to Table 1, the values ​​of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of upper buckle turns (turns) and torsional strength (ft-lbs) of buckle type 03 are: 4, 2, 1:10, 0.05, 8, 23000 respectively.

[0065] In some embodiments, the ranges of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of turns (turns) and torsional strength (ft-lbs) of button type 04 are: 4 1 / 9-4 3 / 8, 2 1 / 7-2 3 / 8, 1:11-1:9, 0.04-0.06, 7-9, 23000-27000, respectively.

[0066] As a preferred embodiment, referring to Table 1, the values ​​of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of upper turns (turns) and torsional strength (ft-lbs) of buckle type 04 are: 4 1 / 8, 2 1 / 8, 1:10, 0.05, 8, 25000 respectively.

[0067] In some embodiments, the ranges of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of turns (turns) and torsional strength (ft-lbs) of button type 05 are: 4 5 / 8-5, 2 9 / 16-2 15 / 16, 1:14-1:11, 0.05-0.07, 6-8, 34000-36000, respectively.

[0068] As a preferred embodiment, referring to Table 1, the values ​​of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of upper turns (turns) and torsional strength (ft-lbs) of buckle type 05 are: 4 7 / 8, 2 11 / 16, 1:12, 0.06, 7, 35000.

[0069] In some embodiments, the ranges of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of turns (turns) and torsional strength (ft-lbs) of button type 06 are: 5 1 / 5-5 3 / 4, 2 3 / 4-3 1 / 3, 1:13-1:10, 0.05-0.07, 6-8, 49000-61000, respectively.

[0070] As a preferred embodiment, referring to Table 1, the values ​​of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of upper turns (turns) and torsional strength (ft-lbs) of button type 06 are: 5 1 / 4, 3, 1:12, 0.06, 7, 50000.

[0071] Drill pipes with buckle type 01, buckle type 02, buckle type 03, buckle type 04, buckle type 05 or buckle type 06 have moderate torsional strength and are suitable for occasions where general torque needs to be transmitted. For example, in the drill pipe connection of some small oil drilling equipment, when the drill pipe rotates and drills, it can effectively transmit torque to ensure the normal operation of the drill bit. At the same time, the tensile strength of this model is also considerable. During the drilling process, the drill pipe needs to withstand its own gravity and the axial tension generated by pulling the drill bit. The higher tensile strength can prevent the drill pipe from breaking during the pulling process, ensuring the safety and reliability of the equipment. In addition, the inner and outer diameters of this model are relatively moderate, and it will not occupy too much space in the internal structure of small drilling equipment with limited space.

[0072] In some embodiments, the ranges of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of turns (turns) and torsional strength (ft-lbs) of button type 07 are: 6 1 / 2-6 7 / 8, 3 3 / 4-4 1 / 3, 1:13-1:10, 0.05-0.07, 6-8, 89000-91000, respectively.

[0073] As a preferred embodiment, referring to Table 1, the values ​​of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of upper buckle turns (turns) and torsional strength (ft-lbs) of buckle type 07 are: 6 5 / 8, 4, 1:12, 0.06, 7, 90000.

[0074] In some embodiments, the ranges of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of turns (turns) and torsional strength (ft-lbs) of button type 08 are: 6 4 / 5-7 2 / 7, 3 3 / 4-4 1 / 2, 1:15-1:12, 0.06-0.08, 5-8, 100000-120000.

[0075] As a preferred embodiment, referring to Table 1, the values ​​of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of upper buckle turns (turns) and torsional strength (ft-lbs) of buckle type 08 are: 7, 4 1 / 4, 1:14, 0.07, 6, 110000.

[0076] In some embodiments, the ranges of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of turns (turns) and torsional strength (ft-lbs) of button type 09 are: 7 7 / 8-8 1 / 8, 4 3 / 4-5 1 / 5, 1:15-1:13, 0.06-0.08, 5-8, 130000-170000, respectively.

[0077] As a preferred embodiment, referring to Table 1, the values ​​of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of upper buckle turns (turns) and torsional strength (ft-lbs) of buckle type 09 are: 8, 5, 1:14, 0.07, 6, 150000.

[0078] In some embodiments, the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of turns (turns) and torsional strength (ft-lbs) of the button type 10 are in the range of 8 1 / 3-8 3 / 4, 4 3 / 4-5 3 / 4, 1:18-1:15, 0.06-0.08, 5-8, 180000-200000 respectively.

[0079] As a preferred embodiment, referring to Table 1, the values ​​of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of upper buckle turns (turns) and torsional strength (ft-lbs) of the buckle type 10 are: 8 1 / 2, 5 1 / 4, 1:16, 0.07, 6, 190000.

[0080] In some embodiments, the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of turns (turns) and torsional strength (ft-lbs) of the button type 11 range from 8 3 / 8 to 8 7 / 8, 5 1 / 4 to 5 3 / 4, 1:18 to 1:15, 0.06 to 0.08, 5 to 8, and 180000 to 190000.

[0081] As a preferred embodiment, referring to Table 1, the values ​​of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of upper buckle turns (turns) and torsional strength (ft-lbs) of the buckle type 11 are: 8 5 / 8, 5 1 / 2, 1:16, 0.07, 6, 185000 respectively.

[0082] In some embodiments, the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of turns (turns) and torsional strength (ft-lbs) of the button type 12 range from 9 1 / 2-10, 5 7 / 8-6 1 / 4, 1:18-1:15, 0.06-0.08, 5-8, 300000-330000, respectively.

[0083] As a preferred embodiment, referring to Table 1, the values ​​of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of upper buckle turns (turns) and torsional strength (ft-lbs) of the buckle type 12 are: 9 7 / 8, 6, 1:16, 0.07, 6, 310000.

[0084] In some embodiments, the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of turns (turns) and torsional strength (ft-lbs) of the button type 13 range from 10 1 / 2-11, 6 1 / 8-7, 1:18-1:15, 0.06-0.08, 5-8, 340000-370000, respectively.

[0085] As a preferred embodiment, referring to Table 1, the values ​​of the outer diameter (in), inner diameter (in), taper, root arc radius (in), number of upper buckle turns (turns) and torsional strength (ft-lbs) of the buckle type 13 are: 10 5 / 8, 6 5 / 8, 1:16, 0.07, 6, 350000.

[0086] The drill pipe with buckle type 08, buckle type 09, buckle type 10, buckle type 11, buckle type 12 or buckle type 13 has high torsional strength, can meet the connection requirements of large torque, can effectively transmit the required torque, and resist the torque fluctuations that occur during drilling to prevent the joint from being damaged due to torque overload. At the same time, this model has high tensile performance and good performance in bearing axial tension. At the same time, the outer diameter of this model is large, which reduces fluid resistance and is conducive to fluid transportation.

[0087]

[0088] Table 1 The embodiment of the present application also provides a torsion-resistant drill pipe joint, including a male joint and a female joint respectively arranged at both ends of the drill pipe, the male joint and the female joint are coaxially arranged, the outer surface of the male joint and the inner surface of the female joint are respectively a first tapered connecting surface and a second tapered connecting surface, and the first tapered connecting surface and the second tapered connecting surface have the same inclination; the first tapered connecting surface and the second tapered connecting surface are respectively provided with an external thread and an internal thread, the external thread is used for threaded connection with the second tapered connecting surface of the female joint of the first drill pipe matched therewith, and the internal thread is used for threaded connection with the first tapered connecting surface of the male joint of the second drill pipe matched therewith; the male joint and the female joint matched therewith and the female joint and the male joint matched therewith respectively correspond to a buckle type, each buckle type has a set range of buckle turns, and each buckle type is determined by the thread parameters of the male joint and the female joint, and the thread parameters of the male joint and the female joint include a tooth bottom arc radius, a tooth profile half angle, a taper and a pitch; the number of buckle turns and the tooth bottom arc radius, the tooth profile half angle, the taper and the pitch satisfy the following relationship: ; In the formula, N is the number of make-up turns, θ is the tooth profile half angle, tpr is the taper, P is the pitch, and R is the tooth bottom arc radius. The number of make-up turns can be accurately calculated through the selected thread parameters, so that the mechanical properties of the threaded connection can be optimized. For example, when the tooth profile half angle, taper, pitch and tooth bottom arc radius are determined according to the design, the number of make-up turns obtained by this relationship can ensure that the stress distribution of the thread is uniform when transmitting huge torque and axial force, avoiding the occurrence of fatigue cracks caused by local stress concentration, thereby significantly improving the fatigue life and reliability of the connection.

[0089] In some embodiments, the partial derivative of the number of make-up turns and the taper satisfies the following relationship: ; Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius. Figure 4In this figure, the horizontal axis represents the taper and the vertical axis represents the number of make-up turns. It can be seen from the figure that when the other thread parameters are fixed, the number of make-up turns is negatively correlated with the taper. Therefore, the change in the number of make-up turns can be accurately controlled by making slight adjustments to the taper, thereby obtaining the changing trend of the relationship between the number of make-up turns and the taper, and providing a theoretical reference for the design of male and female joint threads.

[0090] In some embodiments, reference Figure 4 When the taper is 1 / 10, the corresponding number of make-up turns is 7.01, compared with 1 / 16, the corresponding number of make-up turns is 11.8, which can significantly reduce the number of make-up turns and reduce the non-working time (NPT), thereby improving work efficiency. Compared with 1 / 6 taper, the corresponding number of make-up turns is 4.2, and the male and female joints can be fully connected, thereby improving the make-up speed and efficiency of the connection between the male and female joints.

[0091] In some embodiments, the partial derivative of the number of thread turns and the radius of the tooth bottom arc satisfies the following relationship: ; Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

[0092] refer to Figure 5 In this figure, the horizontal axis represents the arc radius of the tooth bottom, and the vertical axis represents the number of make-up turns. It can be seen from the figure that when the other thread parameters are fixed, the number of make-up turns is negatively correlated with the arc radius of the tooth bottom. Therefore, the change in the number of make-up turns can be accurately controlled by slightly adjusting the arc radius of the tooth bottom, thereby obtaining the relationship between the number of make-up turns and the arc radius of the tooth bottom, and providing a theoretical reference for the thread design of male and female joints.

[0093] In some embodiments, reference Figure 5 , when the radius of the tooth bottom arc is 1.27 When the corresponding number of upper turns is 7.01, or when the radius of the arc at the bottom of the tooth is 0.97 The corresponding number of turns is 8.9, compared with the arc radius of the tooth bottom of 2.1 , the corresponding number of make-up circles is 1.6 circles, the male and female joints can be fully connected, thereby improving the fatigue performance between the male and female joints.

[0094] In some embodiments, the derivative of the number of make-up turns and the pitch satisfies the following relationship: ; Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

[0095] refer to Figure 6In this figure, the horizontal axis represents the pitch and the vertical axis represents the number of make-up turns. It can be seen from the figure that when the other thread parameters are fixed, the number of make-up turns is positively correlated with the pitch. Therefore, the change in the number of make-up turns can be accurately controlled by making slight adjustments to the pitch, thereby obtaining the changing trend of the relationship between the number of make-up turns and the pitch, and providing a theoretical reference for the design of male and female joint threads.

[0096] In some embodiments, reference Figure 6 , when the pitch is 7.257 When the thread pitch is 6.35, the corresponding number of turns is 7.01. , the corresponding number of turns is 6.06, or when the pitch is 10.16 , the corresponding number of make-up circles is 8.92 circles, which can significantly reduce the number of make-up circles and reduce the non-working time (NPT), thereby improving work efficiency.

[0097] In some embodiments, reference Figure 3 In this figure, the horizontal axis represents the half angle of the tooth profile, and the vertical axis represents the number of bends. Figure 3 It can be seen that there is a negative correlation between the number of make-up circles and the tooth profile half angle, that is, as the tooth profile half angle increases, the number of make-up circles decreases accordingly.

[0098] In some embodiments, when the tooth profile half angle is 30°, the corresponding number of bends is 8.0, when the tooth profile half angle is 35°, the corresponding number of bends is 7.0, and when the tooth profile half angle is 45°, the corresponding number of bends is 5.6. This can significantly reduce the number of bends and the non-working time (NPT), thereby improving work efficiency.

[0099] In some embodiments, reference Figure 7 The X-axis coordinate in the figure represents the radius R of the arc at the bottom of the tooth, the Y-axis coordinate represents the taper tpr, and the vertical coordinate represents the number of turns. Figure 7 It can be seen that the influence trend of the two parameter variables of taper and tooth bottom arc radius on the number of make-up turns shows that compared with taper, the tooth bottom arc radius has a greater influence on the number of make-up turns. When adjusting the thread parameters to obtain the corresponding number of make-up turns, the degree of adjustment of the tooth bottom arc and taper (other parameters remain unchanged) can be controlled according to design requirements to obtain different numbers of make-up turns. For example, when it is necessary to quickly adjust the number of make-up turns, it is possible to consider increasing the degree of adjustment of the tooth bottom arc radius within a reasonable range, so as to achieve rapid adjustment of the number of make-up turns.

[0100] In some embodiments, the tooth bottom arc radius and the pitch, tooth profile half angle and taper satisfy the following relationship: ; In the formula, θ is the tooth profile half angle, tpr is the taper, P is the pitch, R is the tooth bottom arc radius, and Rmax is the maximum value of the tooth bottom arc radius. After determining the pitch, tooth profile half angle and taper according to the design requirements, the tooth bottom arc radius is calculated through this relationship, and the stress distribution and deformation of the connection under complex loads are predicted accordingly, which improves the stability of the male and female joint connection.

[0101] In some embodiments, each buckle type has a set range of buckle number and a set range of torsional strength. The setting range of the buckle number is 5-13 turns, and the setting range of torsional strength is not less than 10,000 ft-lbs. The number of buckle turns determines the buckle speed of the drill pipe that cooperates with each other. Generally speaking, the larger the number of buckle turns, the slower the buckle speed, and the smaller the number of buckle turns, the faster the buckle speed. The speed of the buckle speed determines the proportion of non-working time during the drilling and drilling process of the drilling platform. The faster the buckle speed, the smaller the non-working time (NTP, that is, the time occupied by the buckle process), which is equivalent to increasing the actual working time of the drill pipe, which can improve work efficiency. A faster buckle speed means a smaller number of buckle turns. A smaller number of buckle turns may cause the male and female joints to fail to fully cooperate, affecting the connection stability of the male and female joints.

[0102] In addition, the torsional strength of the drill pipe joint determines the maximum stress value that the male and female joints can withstand when subjected to torque, which directly reflects the stability and durability of the male and female joints when subjected to torsion. The higher the torsional strength, the stronger the torsion resistance of the material during torsion deformation, which means that the male and female joints are more solid and durable. At the same time, the higher the torsional strength, the faster the construction speed. Since the drill bit can withstand a greater torque, it can pass through the formation faster, improve the drilling speed and efficiency, and reduce the incidence of drill pipe stuck, thereby improving construction efficiency. Through the coaxial tapered connection surface design, with the precisely set number of buckle circles (5-13 circles) and the torsional strength range of not less than 10000ft-lbs, the joint structure and mechanical properties are optimized to ensure that the drill pipe joint can efficiently, stably and safely transmit torque under complex and harsh drilling conditions, reduce the occurrence of failures, and improve the overall drilling operation efficiency.

[0103] In some embodiments, the radius of the thread bottom arc of each male and female connector in any thread type is in the range of 0.038in-0.08in. In this way, the contact stress distribution of the thread teeth in the axial and circumferential directions can be more uniform. It can withstand the complex alternating loads generated from the marine environment and drilling operations, effectively reduce the stress concentration at the root of the thread, reduce the generation and expansion of fatigue cracks, and ensure the long-term reliability of the pipe string connection under harsh working conditions.

[0104] In some embodiments, the thread profile half angle of each male connector and female connector in any thread type ranges from 27.5° to 44.5°. During the thread connection process of the drill pipe, the thread profile half angle in this range ensures that when the thread is subjected to internal pressure, each thread tooth shares the load evenly, avoiding damage to individual thread teeth due to local stress concentration, thereby significantly improving the overall reliability and sealing of the connection, effectively preventing medium leakage, and ensuring the safe and stable operation of the pipeline system.

[0105] In some embodiments, the taper of each male and female connector in any thread type ranges from 1 / 16 to 1 / 6. In this way, the male and female connectors can gradually achieve a close fit during the tightening process, especially forming a reliable sealing contact at the sealing surface. As the threading progresses, the contact pressure between the threads and the sealing surface increases evenly, maximizing the threading speed and efficiency between the male and female connectors.

[0106] In some embodiments, when the buckle type is a design buckle type, the taper and the tooth bottom arc radius also satisfy the following corresponding relationship: when the taper is 1 / 16, the corresponding tooth bottom arc radius ranges from 0.05in to 0.065in; when the taper is 1 / 12, the corresponding tooth bottom arc radius ranges from 0.04in to 0.060in; when the taper is 1 / 10, the corresponding tooth bottom arc radius ranges from 0.045in to 0.055in. This makes the stress distribution of the threaded connection more uniform and reasonable, effectively reduces stress concentration, and enhances the bearing capacity and fatigue resistance of the connection, so that it can cope with a variety of complex loads.

[0107] In some embodiments, the pitch of each male and female connector in any buckle type ranges from 0.250in to 0.364in. This enables the force distribution of the male and female connectors to be more uniform when subjected to huge tensile forces. Compared with pitches that are too dense or too sparse, within this range, each circle of thread can effectively share the load, reduce stress concentration, and prevent deformation or damage of the thread due to excessive local force.

[0108] The embodiment of the present application also provides a drill pipe joint design method, including: the first step, determining the range of the number of beading circles and torsional strength of the designed buckle type according to the number of beading circles and torsional strength of the standard buckle type and the special buckle type, wherein the number of beading circles of the designed buckle type is 5-13 circles, and the setting range of torsional strength is not less than 10000ft-lbs; the second step, setting the thread parameters in the designed buckle type, the thread parameters include the tooth bottom arc radius, taper, tooth profile half angle and pitch, and selecting the tooth profile radius and pitch according to the range of the number of beading circles and torsional strength; the third step, selecting a series of taper ranges according to the range of the number of beading circles and torsional strength; the fourth step, according to the relationship between the thread parameters and the number of beading circles, obtaining a series of ranges of the tooth bottom arc radius corresponding to the taper range. It is possible to determine the key parameter range of the designed buckle type according to the empirical data of the standard buckle type and the special buckle type, and has good flexibility. For example, in the field of oil production, different oil well depths, geological conditions and production processes have very different requirements for drill pipe joints. Through this design method, suitable drill pipe joints can be designed for specific conditions such as shallow wells, deep wells, ultra-deep wells or different rock formations. For shallow wells with relatively simple geological conditions, a lower torsional strength can be selected without considering the influence of the number of make-up circles, such as 10 circles and a lower torsional strength in the corresponding specification (such as 20,000 ft-lbs); while for the exploitation of deep wells, ultra-deep wells or horizontal wells, a higher torsional strength (110,000 ft-lbs) and a smaller number of make-up circles (such as 6 circles) in the corresponding specification are selected to meet the use requirements under complex working conditions.

[0109] In some embodiments, the number of make-up turns and the arc radius of the tooth bottom, the tooth profile half angle, the taper and the pitch satisfy the following relationship: ; In the formula, N is the number of make-up turns, θ is the tooth profile half angle, tpr is the taper, P is the pitch, and R is the tooth bottom arc radius. The number of make-up turns can be accurately calculated through the selected thread parameters, so that the mechanical properties of the threaded connection can be optimized. For example, when the tooth profile half angle, taper, pitch and tooth bottom arc radius are determined according to the design, the number of make-up turns obtained by this relationship can ensure that the stress distribution of the thread is uniform when transmitting huge torque and axial force, avoiding the occurrence of fatigue cracks caused by local stress concentration, thereby significantly improving the fatigue life and reliability of the connection.

[0110] In some embodiments, it is necessary to select a suitable number of make-up turns and torsional strength, and select a better number of make-up turns and torsional strength within a reasonable range of make-up turns (between the theoretical minimum number of make-up turns and the maximum number of make-up turns) and a reasonable range of torsional strength (theoretically the minimum torsional strength) to better meet the requirements for make-up speed and torsional performance. Referring to Table 2, according to the various buckle types on the market, taking the NC38 buckle type (standard buckle type) and the special buckle type HLIST39 in the API standard as examples, the NC38 in the API standard is the most basic buckle type with torsional performance in the current market, and the HLIST39 is a special buckle type with better torsional performance. The range of the number of make-up turns is selected to be 5 turns to 13 turns, and the range of torsional strength is selected to be not less than 32300ft-lbs, to ensure that the male and female joints have a suitable number of make-up turns, reduce the non-working time (NPT), and the torsional strength of the male and female joints is also more appropriate, which can meet the use requirements of the drill pipe.

[0111]

[0112] Table 2 Moreover, although the number of make-up circles of 5 to 13 circles has met the requirements for make-up speed, it is still possible to further divide the number of make-up circles into three ranges according to the requirements of the drill pipe make-up speed at the drilling site: high-efficiency range (5.0~7.3), medium range (7.4~10.5), and general range (10.6~13.0). The high-efficiency range (5.0~7.3) is suitable for short construction periods that require a significant reduction in non-working time, while the medium range (7.4~10.5) and general range (10.6~13.0) are suitable for situations that require better male and female joint connection.

[0113] In some embodiments, referring to Table 3, the taper and the tooth bottom arc radius also satisfy the following corresponding relationship: when the taper is 1 / 16, the corresponding tooth bottom arc radius ranges from 0.05in to 0.065in; when the taper is 1 / 12, the corresponding tooth bottom arc radius ranges from 0.04in to 0.060in; when the taper is 1 / 10, the corresponding tooth bottom arc radius ranges from 0.045in to 0.055in. This makes the stress distribution of the threaded connection more uniform and reasonable, effectively reduces stress concentration, enhances the bearing capacity and fatigue resistance of the connection, and can cope with a variety of complex loads.

[0114]

[0115] Table 3 In some embodiments, the torsional strength of the male and female connectors is calculated by the following formula:

[0116] In the formula, is the dangerous cross-sectional area at the column shoulder position, in units of ; is the dangerous cross-sectional area at the auxiliary shoulder position, in units of ; is the average radius of the main shoulder contact ring, in units of ; is the average radius of the contact ring of the secondary shoulder surface, in units of ; is the yield torque, in units of ; is the minimum yield strength of the material, in units of ; is the thread pitch, in units of ; is the actual friction coefficient of the contact surface between the shoulder and the thread, which is generally 0.08 for drill pipe design; It is the half angle of the thread profile; , is the average radius of the threaded part of the joint, in units of ; is the length of the male connector; ,in, The maximum value is subject to = Calculated at restrictions; ; is the dangerous section of the main shoulder, , The smaller value of the two; , when there is no stress relief groove; , when there is a stress relief groove; is the diameter of the stress relief groove; is the reference pitch diameter of the thread at a specified point on the gauge; inner diameter; outer diameter; ; The original triangle height of the thread; Thread bottom cut-off height; Taper; ; Boring diameter of the female connector; ; The nose diameter of the male connector; .

[0117] Combined with Table 1, it can be seen from the above formula that the torsional strength of each buckle type is also related to the inner diameter, outer diameter, taper, pitch, tooth profile half angle and other parameters corresponding to the male and female joints. When the other parameters in the torsion formula remain unchanged, the torsional strength requirements of the drill pipe joint can be adjusted according to the actual working conditions. By adjusting the various geometric parameters of the joint (inner diameter, outer diameter, taper, pitch, tooth profile half angle), the torsional strength suitable for the design requirements can be obtained. For example, when designing a drill pipe joint for deep well drilling, due to the need to withstand higher torque, the torsional strength of the joint can be calculated and optimized according to the formula by increasing the outer diameter, inner diameter or adjusting the middle diameter of the thread and other parameters to ensure that it can meet the drilling requirements under complex geological conditions in deep wells. In addition, this formula helps to accurately predict the torsional performance of the drill pipe joint. By entering different combinations of geometric parameters, a more accurate estimate of the torsional strength of the drill pipe joint can be made in advance. For example, when developing high-strength drill pipe joints, a formula is used to calculate the torsional strength and compare it with the torque output capacity of existing drilling equipment to determine whether the new joint can be adapted, thus avoiding problems such as connection failure or equipment damage caused by insufficient or excessive torsional strength.

[0118] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0119] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0120] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0121] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A torsion-resistant drill pipe joint, characterized in that: The drill pipe comprises a male joint and a female joint respectively arranged at both ends of the drill pipe, the male joint and the female joint are coaxially arranged, the outer surface of the male joint and the inner surface of the female joint are respectively a first tapered connection surface and a second tapered connection surface, and the first tapered connection surface and the second tapered connection surface have the same inclination; the first tapered connection surface and the second tapered connection surface are respectively provided with an external thread and an internal thread, the external thread is used for threaded connection with the second tapered connection surface of the female joint of the first drill pipe matched therewith, and the internal thread is used for threaded connection with the first tapered connection surface of the male joint of the second drill pipe matched therewith; The male connector and the female connector that match it, and the female connector and the male connector that match it correspond to a buckle type, each of the buckle types is determined by the thread parameters of the male connector and the corresponding female connector, each of the buckle types has a set range of buckle turns and torsional strength, the setting range corresponding to the buckle turns is 5 turns to 13 turns, and the setting range corresponding to the torsional strength is not less than 10000 ft-lbs; the buckle turns and the thread parameters also satisfy the following relationship: ； Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

2. The torsion-resistant drill pipe joint according to claim 1, characterized in that: The thread parameters of the male connector and the female connector include a tooth bottom arc radius, and the tooth bottom arc radius of each of the male connector and the female connector in any thread type ranges from 0.038in to 0.08in.

3. The torsion-resistant drill pipe joint according to claim 2, characterized in that: The thread parameters of the male connector and the female connector also include a thread profile half angle, and the thread profile half angle of each of the male connector and the female connector in any thread type ranges from 27.5° to 44.5°.

4. The torsion-resistant drill pipe joint according to claim 3, characterized in that: The thread parameters of the male connector and the female connector also include taper, and the taper range of each of the male connector and the female connector in any thread type is 1 / 16 - 1 / 6.

5. The torsion-resistant drill pipe joint according to claim 4, characterized in that: When the buckle type is a designed buckle type, the taper and the tooth bottom arc radius also satisfy the following corresponding relationship: when the taper is 1 / 16, the corresponding tooth bottom arc radius range is 0.05in~0.065in; when the taper is 1 / 12, the corresponding tooth bottom arc radius range is 0.04in~0.060in; when the taper is 1 / 10, the corresponding tooth bottom arc radius range is 0.045in~0.055in.

6. The torsion-resistant drill pipe joint according to claim 5, characterized in that: The thread parameters of the male connector and the female connector also include a pitch, and the pitch range of each of the male connector and the female connector in any thread type is 0.250in-0.364in.

7. The torsion-resistant drill pipe joint according to claim 6, characterized in that: The partial derivative of the number of make-up turns and the taper satisfies the following relationship: ； Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

8. The torsion-resistant drill pipe joint according to claim 7, characterized in that: The partial derivative of the number of thread turns and the radius of the tooth bottom arc satisfies the following relationship: ； Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

9. The torsionally resistant drill pipe joint according to claim 8, characterized in that: The partial derivative of the number of make-up turns and the pitch satisfies the following relationship: ； Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

10. The torsionally resistant drill pipe joint according to claim 9, characterized in that: The tooth bottom arc radius, the thread pitch, the tooth profile half angle and the taper satisfy the following relationship: ； Where θ is the tooth profile half angle, tpr is the taper, P is the pitch, R is the tooth bottom arc radius, and Rmax is the maximum value of the tooth bottom arc radius.

11. A torsion-resistant drill pipe joint, characterized in that: The drill pipe comprises a male joint and a female joint respectively arranged at both ends of the drill pipe, the male joint and the female joint are coaxially arranged, the outer surface of the male joint and the inner surface of the female joint are respectively a first tapered connection surface and a second tapered connection surface, and the first tapered connection surface and the second tapered connection surface have the same inclination; the first tapered connection surface and the second tapered connection surface are respectively provided with an external thread and an internal thread, the external thread is used for threaded connection with the second tapered connection surface of the female joint of the first drill pipe matched therewith, and the internal thread is used for threaded connection with the first tapered connection surface of the male joint of the second drill pipe matched therewith; The male connector and the female connector matched therewith and the female connector and the male connector matched therewith respectively correspond to a buckle type, each buckle type has a set range of buckle turns, each buckle type is determined by the thread parameters of the male connector and the female connector, and the thread parameters of the male connector and the female connector include the tooth bottom arc radius, the tooth profile half angle, the taper and the pitch; the number of buckle turns and the tooth bottom arc radius, the tooth profile half angle, the taper and the pitch satisfy the following relationship: ； Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

12. The torsionally resistant drill pipe joint according to claim 11, characterized in that: The partial derivative of the number of make-up turns and the taper satisfies the following relationship: ； Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

13. The torsionally resistant drill pipe joint according to claim 11, characterized in that: The partial derivative of the number of thread turns and the radius of the tooth bottom arc satisfies the following relationship: ； Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

14. The torsionally resistant drill pipe joint according to claim 11, characterized in that: The partial derivative of the number of make-up turns and the pitch satisfies the following relationship: ； Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

15. The torsionally resistant drill pipe joint according to claim 11, characterized in that: The tooth bottom arc radius, the thread pitch, the tooth profile half angle and the taper satisfy the following relationship: ； Where θ is the tooth profile half angle, tpr is the taper, P is the pitch, R is the tooth bottom arc radius, and Rmax is the maximum value of the tooth bottom arc radius.

16. The torsionally resistant drill pipe joint according to claim 11, characterized in that: Each of the buckle types has a set range of buckle turns and a set range of torsional strength, the set range of the buckle turns is 5 turns to 13 turns, and the set range of torsional strength is not less than 10,000 ft-lbs.

17. The torsionally resistant drill pipe joint according to claim 11, characterized in that: The radius of the thread bottom arc of each of the male connector and the female connector in any buckle type ranges from 0.038in to 0.08in.

18. The torsionally resistant drill pipe joint according to claim 11, characterized in that: The thread profile half angle of each of the male connector and the female connector in any buckle type ranges from 27.5° to 44.5°.

19. The torsionally resistant drill pipe joint according to claim 11, characterized in that: The taper of each of the male connector and the female connector in any buckle type ranges from 1 / 16 to 1 / 6.

20. The torsionally resistant drill pipe joint according to claim 11, characterized in that: When the buckle type is a designed buckle type, the taper and the tooth bottom arc radius also satisfy the following corresponding relationship: when the taper is 1 / 16, the corresponding tooth bottom arc radius range is 0.05in~0.065in; when the taper is 1 / 12, the corresponding tooth bottom arc radius range is 0.04in~0.060in; when the taper is 1 / 10, the corresponding tooth bottom arc radius range is 0.045in~0.055in.

21. The torsionally resistant drill pipe joint according to claim 11, characterized in that: The pitch range of each of the male connector and the female connector in any buckle type is 0.250in-0.364in.

22. A drill pipe joint design method, characterized in that: include: Determine the setting range of the number of beading turns and the torsional strength of the designed buckle type according to the number of beading turns and the torsional strength of the standard buckle type and the special buckle type respectively; wherein the setting range corresponding to the number of beading turns of the designed buckle type is 5 turns to 13 turns, and the setting range corresponding to the torsional strength of the designed buckle type is not less than 10000 ft-lbs; Set the thread parameters of the designed thread type, which include the tooth bottom arc radius, taper, tooth profile half angle and pitch. The tooth profile radius and pitch are selected according to the number of beading turns and the range of torsional strength; Select the taper range of the series according to the number of make-up circles and the range of torsional strength; According to the relationship between the thread parameters and the number of make-up turns, a series range of tooth bottom arc radii corresponding to the taper range is obtained.

23. The drill rod joint design method according to claim 22, characterized in that: The number of make-up circles and the tooth bottom arc radius, the tooth profile half angle, the taper and the pitch satisfy the following relationship: ； Where N is the number of thread turns, θ is the thread half angle, tpr is the taper, P is the thread pitch, and R is the thread bottom arc radius.

24. The drill rod joint design method according to claim 22, characterized in that: The taper and the tooth bottom arc radius also satisfy the following corresponding relationship: when the taper is 1 / 16, the corresponding tooth bottom arc radius range is 0.05in~0.065in; when the taper is 1 / 12, the corresponding tooth bottom arc radius range is 0.04in~0.060in; when the taper is 1 / 10, the corresponding tooth bottom arc radius range is 0.045in~0.055in.

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