RU200381U1 - THREADED DRILL PIPE CONNECTION - Google Patents

Abstract

Proposed is a threaded joint for drill pipes, comprising: a nipple and a sleeve, each provided with a thread; moreover, each of the nipple and the coupling has a thrust ledge and contains a spout with a thrust end, and the thread of the nipple and the thread of the coupling are made with the possibility of interaction with each other to ensure the abutment of the thrust end of the nipple nose to the thrust ledge of the coupling and the possibility of the abutment of the thrust end of the coupling nose to the thrust nipple ledge; the thread of the nipple and the thread of the box each have a taper of 1: 6 mm / mm and the pitch of the thread in the range from 6.3 mm to 6.4 mm, and the length of the nose of the box is in the range from 14.2 mm to 17.5 mm. 3 C.p. f-ly, 4 dwg

Description

FIELD OF TECHNOLOGY

This utility model relates to drill pipes, in particular to threaded connections, which can be used, in particular, to connect drill pipes to each other and to other components of drill strings used in drilling vertical, directional and horizontal oil and gas wells ...

LEVEL OF TECHNOLOGY

Currently, vertical drilling, directional drilling and horizontal drilling, as well as drilling of sidetracks, are increasingly being used in the world, in particular in the Russian Federation, when creating oil and gas wells.

During rotary drilling of oil and gas wells, an increased torque is applied to drill pipes and other structural elements of the drill string. In addition, drilling pipes and other structural elements of the drill string are subjected to high bending loads when drilling in difficult conditions in curved wellbores (directional and horizontal wells, sidetracks, etc.).

To work in the above-described difficult drilling conditions, drill pipes with special threaded connections (so-called drill joints) are used, which are designed to connect drill pipes with each other and with other structural elements of drill strings, while such special threaded connections must have increased resistance to torsion and bending loads.

Increasingly challenging conditions for drilling oil and / or gas wells are driving the need to develop threaded connections for drill pipes with improved performance characteristics.

One of the illustrative examples of a threaded joint for drill pipes is described in the patent of the Russian Federation No. 88729 (hereinafter RU 88729), published on November 20, 2009. In particular, the patent RU 88729 discloses a threaded joint for drill pipes, comprising: a nipple and a sleeve, each provided with a thread; moreover, each of the nipple and the coupling has a thrust ledge and contains a spout with a thrust end, and the thread of the nipple and the thread of the coupling are made with the ability to interact with each other to ensure the abutment of the thrust end of the nipple nose to the thrust ledge of the coupling and the possibility of abutting the thrust end of the coupling nose to the thrust nipple ledge.

The disadvantage of the threaded joint for drill pipes, described in RU 88729, is that it does not retain its operational properties when operating in difficult drilling conditions, in particular when it is subjected to increased torsional and bending loads. In particular, it should be noted that if the drill string gets stuck in the wellbore while drilling horizontal wells, directional wells or sidetracks, the drilling torque may be exceeded compared to the torque used when making up a threaded connection (in particular, when assembling drill string) on the surface of the well, as a result of which an additional make-up torque may occur, which has an increased effect on the threaded connection according to RU 88729, which may exceed the yield point of the material of the pin and / or sleeve of this threaded connection according to RU 88729 and, therefore, cause their destruction ... To prevent the occurrence of the above-described cases of destruction of the threaded joint of the drill pipes, the torque applied to the threaded joint when making up the drill pipes must always be higher than the torque applied to the threaded joint during drilling, with a margin that takes into account difficult drilling conditions or possible emergency situations, for example, stuck drill string in the wellbore.

Thus, there is an obvious need for further improvement of threaded connections for drill pipes, in particular for improving the resistance of such threaded connections to increased torques and, consequently, their reliability.

Therefore, the technical problem solved by the present invention consists in creating a threaded joint for drill pipes, which at least partially eliminates the above-mentioned disadvantage of the known threaded joint for drill pipes, which consists in the possibility of destruction of the threaded joint of drill pipes during drilling.

DISCLOSURE OF THE USEFUL MODEL

The aforementioned technical problem is solved in the present utility model due to the fact that in the proposed threaded joint of drill pipes, comprising a nipple and a sleeve, each provided with a thread; moreover, each of the nipple and the coupling has a thrust ledge and contains a spout with a thrust end, and the thread of the nipple and the thread of the coupling are made with the ability to interact with each other to ensure the abutment of the thrust end of the nipple nose to the thrust ledge of the coupling and the possibility of abutting the thrust end of the coupling nose to the thrust nipple ledge; the nipple threads and the box threads each have a taper of 1: 6 mm / mm and the thread pitch ranges from 6.3 mm to 6.4 mm, and the length of the box nose ranges from 14.2 mm to 17.5 mm.

The threaded connection of drill pipes according to the present utility model provides a technical result, which consists in increasing its strength, which allows the specified threaded connection to withstand increased torques, in particular when using drill pipes in difficult operating conditions when drilling sidetracks, liners in directional and horizontal wells, as well as during various repair and technological operations, in which large torsion moments may occur. In particular, the increase in the strength of the threaded connection of the drill pipes according to the present invention is due to the achievement in the specified threaded connection of the optimal ratio between the torque received by this threaded connection and the stress level arising when the stop end of the coupling nose is adjacent to the stop shoulder of the nipple, which allows increase the resistance of the threaded connection to increased torque.

In one embodiment of the present invention, the thread pitch of the pin and box may be 6.35 mm, and the length of the nose of the box in the drill pipe threaded joint may be 15.875 mm.

In yet another embodiment of the present invention, the pin and box thread pitch may be 6.35 mm, and the length of the box nose in the drill pipe threaded joint may be 15.875 mm.

The above values of the pitch of the thread for the pin and the nose and the length of the nose of the coupling in the threaded joint of the drill pipes according to the present invention also provide the above-stated technical result, which consists in increasing the strength of the threaded joint of the drill pipes.

In another embodiment of the present invention, the pin thread and the box thread may each have a height ranging from 3 mm to 3.2 mm.

In yet another embodiment of the present invention, the height of the pin and box threads may be 3.095 mm.

The above values of the thread height of the pin and the thread of the box also make their additional contribution to the above-formulated technical result, which consists in increasing the strength of the threaded connection of drill pipes.

Brief Description of Drawings

The accompanying drawings, which are shown to provide a better understanding of the essence of the present utility model, form a part of this document and are included in it to illustrate the below-described embodiments of the present utility model. The accompanying drawings in combination with the description below serve to clarify the essence of the present utility model. In the drawings:

in fig. 1 shows a threaded joint for drill pipes according to the present invention in the unscrewed state;

in fig. 2 shows a threaded joint for drill pipes according to the present utility model in a screwed state;

in fig. 3 shows a portion of the nipple of the threaded joint shown in FIG. 1 and 2;

in fig. 4 shows a portion of a sleeve of the threaded joint shown in FIG. 1 and 2.

DISCLOSURE OF THE USEFUL MODEL

FIG. 1 shows a threaded joint 100 of drill pipes in a loose state.

The threaded joint 100 of the drill pipe shown in FIG. 1, contains a nipple 1 and a sleeve 2, made with the possibility of threaded interaction with each other when screwing or unscrewing the threaded connection 100, providing, respectively, connection and disconnection of the threaded connection 100.

The nipple 1 is provided with a conical thread 3 made on the surface of the nipple 1, which faces towards the coupling 2 when the nipple 1 and the coupling 2 are in threaded engagement with each other. Thus, the thread 3 of the nipple is made on the outside of the nipple 1, opposite to the inside of the nipple 1, with which it faces the inner cavity of the drill pipes, intended to pass the fluid associated with drilling wells using these drill pipes.

In addition, the sleeve 2 is provided with a tapered thread 6 made on the sleeve surface, which faces the nipple 1 when the sleeve 2 and the nipple 1 interact with each other. Thus, the thread 6 of the sleeve is made on the inner side of the sleeve 2 opposite to the outer side of the sleeve 2, with which it faces the environment surrounding the drill pipes.

In addition, as shown in FIG. 1, the nipple 1 has a stop shoulder 4 and contains a nose 11 with a stop end 5, and the coupling 2 has a stop 7 and contains a nose 12 with a stop end 8.

In addition, the thread 3 of the nipple and the thread 6 of the box each have a taper of 1: 6 mm / mm, a pitch in the range of 6.3 mm to 6.4 mm, and preferably 6.35 mm (i.e., have 4 turns per inch (25.4 mm)), and thread heights in the range of 3 mm to 3.2 mm (preferably 3.095 mm). The thread 3 of the pin and the thread 6 of the box are made with the possibility of detachable connection or interaction with each other with the formation of an external stop unit 9 and an internal stop unit 10, as shown in FIG. 2.

The main functions of the thread 3 of the nipple and the thread 6 of the coupling are the perception of a tensile load and withstanding multiple make-up and unscrewing of the threaded connection 100 while maintaining its operational characteristics.

It should be noted that the execution of each of the thread 3 of the nipple and the thread 6 of the coupling with a taper of 1: 6 mm / mm and a thread pitch in the range from 6.3 mm to 6.4 mm (preferably 6.35 mm) is optimal, since it provides optimal the ratio between the make-up time of the threaded connection 100, which will increase with an increase in the taper of the thread 3 of the nipple and the thread 6 of the coupling and will decrease with an increase in the thread pitch for the thread 3 of the nipple and the thread 6 of the coupling, and the resistance of the threaded connection 100 to high torque when drilling in difficult conditions increasing with increasing taper of thread 3 of the nipple and thread 6 of the coupling.

The inner thrust assembly 10 is formed by the thrust end 5 of the nipple nose and the thrust shoulder 7 of the coupling, and the outer thrust assembly 9 is formed by the thrust end 8 of the nose of the coupling and the thrust shoulder 4 of the nipple.

It should be noted that the outer thrust assembly 9 provides for the transmission of high torque while drilling a well, and is also sealing and ensures the tightness of the threaded joint 100. The inner thrust assembly 10 complements the outer thrust assembly 9 and provides the transmission of the torque received by the threaded joint 100.

As shown in FIG. 1, the nose 11 of the nipple with the stop end 5 has a length L ₁ , and the nose 12 of the coupling with the stop end 8 has a length L ₂ , while in the threaded connection 100 the stop end 5 of the nipple and the stop end 8 of the coupling are made in such a way that the length L ₂ the spout 12 of the box is greater than the length L _{1 of the} spout 11 of the nipple, while the length L _{1 of the} spout 11 of the nipple has a value in the range from 10.1 mm to 11 mm (L _{1 is} preferably 10.24 mm or 10.85 mm), and the length L _{2 of the} clutch nose 12 has a value in the range of 14.2 mm to 17.5 mm (L _{2 is} preferably 15.875 mm).

It should be noted that the authors of this document have found that in the case where the thread 3 of the nipple and the thread 6 of the box each have a taper of 1: 6 mm / mm and a pitch in the range of 6.3 mm to 6.4 mm (preferably 6, 35 mm), and the length L _{1 of the} nipple nose 11 is in the range from 10.1 mm to 11 mm (preferably 10.24 mm or 10.85 mm), an optimal ratio is achieved between the torque received by the threaded connection 100 and the level stresses on the thrust assembly 10 arising from the abutment of the thrust end 5 of the nipple nose to the thrust ledge 7 of the coupling, which improves the reliability of the threaded connection 100 and the ability to withstand large loads (in particular, torque) without destruction, in particular in difficult drilling conditions. Thus, the above relationship between the parameters of the threads 3, 6 and the length L _{1 of the} nose 11 of the nipple not only ensures the operability of the threaded connection 100, but also allows the load to be evenly distributed over the threads of the thread 3 of the nipple to ensure reliable transmission of the axial load from the nipple 1 to the coupling 2 by thread 3 of the nipple and its balancing by the internal stop unit 10. In addition, the above optimal ratio between the torque received by the threaded connection 100 and the stress level on the stop unit 10, which occurs when the stop end 5 of the nipple nose is adjacent to the stop shoulder 7 of the coupling, is also achieved and with a thread height 3 of the nipple and thread 6 of the coupling from 3 mm to 3.2 mm (preferably 3.095 mm), while the specified range of values for the height of the thread 3 of the nipple and the thread 6 of the coupling (including the above-mentioned specific value of the height of the thread 3 of the nipple and thread 6 coupling) allows the threaded connection 100 to withstand heavy loads (in particular, cr dull moment) without destruction.

The authors of this document have also found that in the case where the thread 3 of the nipple and the thread 6 of the box each have a taper of 1: 6 mm / mm and a pitch in the range of 6.3 mm to 6.4 mm (preferably 6.35 mm) , and the length L _{2 of the} nose 12 of the clutch is in the range from 14.2 mm to 17.5 mm (preferably 15.875 mm), an optimal ratio is achieved between the torque received by the threaded connection 100 and the stress level on the outer thrust assembly 9 that occurs when abutting the stop end 8 of the nose of the coupling to the stop shoulder 4 of the nipple, which makes it possible to further improve the reliability of the threaded connection 100 and the ability to withstand large loads (in particular, torque) without destruction, in particular in difficult drilling conditions. Thus, the above relationship between the parameters of the threads 3, 6 and the length L _{2 of the} nose 12 of the coupling not only ensures the operability of the threaded connection 100, but also makes it possible to evenly distribute the loads along the threads 6 of the coupling to ensure reliable transmission of the axial load from the coupling 2 to the nipple 1 by means of the thread 6 of the coupling and balancing it with the external stop unit 9. In addition, the above-mentioned optimal ratio between the torque received by the threaded connection 100 and the stress level on the external stop unit 9 arising when the stop end 8 of the coupling nose is adjacent to the stop shoulder 4 of the nipple , is also achieved with a thread height 3 of the nipple and thread 6 of the coupling from 3 mm to 3.2 mm (preferably 3.095 mm), while the specified range of values for the height of the thread 3 of the nipple and the thread 6 of the coupling (including the above specific value of the thread height 3 nipple and thread 6 of the coupling) allows the threaded connection 100 to withstand heavy loads (in hours strength, torque) without destruction.

In addition, the authors of this document have found that in the case where the thread 3 of the nipple and the thread 6 of the box each have a taper of 1: 6 mm / mm and a pitch in the range of 6.3 mm to 6.4 mm (preferably 6.35 mm), the length L _{1 of the} nipple spout 11 is in the range from 10.1 mm to 11 mm (preferably 10.24 mm or 10.85 mm), and the length L _{2 of the} collar spout 12 is in the range from 14.2 mm to 17.5 mm (preferably 15.875 mm), an optimal ratio is achieved between the torque received by the threaded joint 100 and the uniform distribution of stresses along the outer and inner thrust assemblies 9, 10, while optimizing the overall dimensions of the joint depending on the diameter of the drill pipes used.

In addition, the length L _{1 of the} spout 11 of the nipple in the above limit ([10.1 mm; 11 mm]), including at its above-mentioned specific values (10.24 mm or 10.85 mm), makes it possible to technologically perform threading, respectively 3 nipples on the outer surface of the nipple 1 and cutting the thread 6 of the box on the inner surface of the box 2.

Thus, the length L _{1 of the} spout 11 of the nipple in the above range of values and / or the length L _{2 of the} spout 12 of the coupling in the above range of values, in combination with the above parameters of the thread 3 of the nipple and the thread 6 of the coupling ensure that the threaded connection 100 has not only high strength characteristics in tension, bending and shearing, but also has a high speed and less laboriousness of its screwing and / or unscrewing.

As shown in FIG. 3, the nipple 1 is also provided with a sealing shoulder 13, the upper edge of which is located at a distance L ₃ in the range from 2.925 mm to 3.425 mm (preferably the distance L ₃ is 3.175 mm) from the thrust shoulder 4 of the nipple, while the upper platform of the sealing shoulder 13 of the nipple, connected to the thrust shoulder 4 of the nipple, and the lower platform of the sealing shoulder 13 of the nipple, located below the upper platform of the sealing shoulder 13 of the nipple along the height of the nipple, are generally rectilinear, and the height of the sealing shoulder 13 of the nipple is generally in the range from 0.2 mm to 0 , 6 mm (preferably the height of the sealing shoulder 13 of the nipple is 0.4 mm).

As shown in FIG. 4, the coupling 2 is also equipped with a sealing shoulder 14, the upper edge of which is located at a distance L ₄ in the range from 2.925 mm to 3.425 mm (preferably the distance L ₄ is 3.175 mm) from the thrust end 8 of the coupling nose, while the upper platform of the sealing shoulder 14 of the coupling connected to the thrust end 8 of the clutch nose is generally rectilinear, the lower platform of the sealing shoulder 14 of the sleeve, located below the upper platform of the sealing shoulder 14 of the sleeve along the height of the sleeve 2, is generally inclined, and the height of the sealing shoulder 14 of the sleeve is generally in the range 0.1 mm to 0.3 mm (preferably, the height of the sleeve sealing shoulder 14 is 0.2 mm).

Thus, as described above, the pin seal shoulder 13 is generally located at a distance L ₃ from the pin shoulder 4 that is substantially the same as or equal to the distance at which the box seal shoulder 14 is generally located.

It should be noted that when the thread 3 of the pin and the thread 6 of the box are introduced in cooperation with the provision of the formation, in particular, of the external stop unit 9, as shown in FIG. 2 and described above in this document with reference to FIG. 2, the sealing shoulder 13 of the pin comes into close contact or tight engagement with the sealing shoulder 14 of the box, in which the above-described upper platform and the lower platform of the shoulder 13 of the pin at least partially come into close interaction, respectively, with the upper platform and the lower platform of the thread 6 of the box, which ultimately improves the strength and tightness of the outer abutment assembly 9 and, therefore, the threaded connection 100 as a whole.

Threaded connection 100 drill pipes works as follows. When screwing the threaded connection 100, the nipple 1 and the coupling 2 are connected to each other by introducing the thread 3 of the nipple into interaction with the thread 6 of the coupling, as a result of which the nipple 1 moves along the coupling 2, ensuring the abutment of the stop end 5 of the nose 11 of the nipple to the stop shoulder 7 of the coupling or their closure, as a result of which an internal stop unit 10 is formed, close to the inner cavity of the drill pipes (see Fig. 2), designed to pass the fluid associated with drilling wells, and the abutment of the stop end 8 of the nose 12 of the coupling to the stop shoulder 4 nipples or their closure, as a result of which an external stop unit 9 is formed, which is remote from the inner cavity of the drill pipes and close to the environment surrounding the drill pipes (see Fig. 2). In addition, in the above-described process of connecting the pin 1 and the box 2 to each other, the sealing shoulder 13 of the pin also comes into close contact with the sealing shoulder 14 of the box. When unscrewing the threaded connection 100, the nipple 1 and the coupling 2 are disconnected from each other by withdrawing the thread 3 of the nipple from interaction with the thread 6 of the coupling, as a result of which the nipple 1 moves along the coupling 2 in the opposite direction, ensuring the gradual removal of the stop end 5 of the nose 11 of the nipple from the stop shoulder 7 of the sleeve and, accordingly, the removal of the stop end 8 of the nose 12 of the sleeve from the stop shoulder 4 of the nipple, while the sealing shoulder 13 of the pin and the sealing shoulder 14 of the sleeve are removed from interaction with each other.

Claims (4)

1. Threaded connection of drill pipes, containing a nipple and a sleeve, each equipped with a thread, and each of the nipple and the sleeve has a thrust ledge and contains a spout with a thrust end, and the thread of the nipple and the thread of the sleeve are made with the possibility of interaction with each other with the possibility of abutting the thrust the end of the nipple nose to the stop shoulder of the coupling and the possibility of abutting the stop end of the nose of the coupling to the stop shoulder of the nipple, characterized in that the thread of the nipple and the thread of the coupling each have a taper of 1: 6 mm / mm and a pitch in the range from 6.3 mm to 6, 4 mm, and the length of the coupling nose ranges from 14.2 mm to 17.5 mm. 2. A threaded joint for drill pipes according to claim 1, wherein said thread pitch is 6.35 mm and the length of the nose of the coupling is 15.875 mm. 3. Threaded connection of drill pipes according to any one of paragraphs. 1-3, in which the pin thread and the box thread each have heights ranging from 3 mm to 3.2 mm. 4. Threaded connection of drill pipes according to any one of paragraphs. 1-3, in which the height of the pin and box threads is 3.095 mm.

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