RU181276U1 - DRILL PIPE THREADED CONNECTION - Google Patents

Abstract

A threaded connection of drill pipes, including the nipple and sleeve ends with a trapezoidal tapered thread, with two stops (external and internal), characterized in that the internal stop of the nipple end has conical and cylindrical sections, and the internal bore in the sleeve end is equipped with a toroidal pocket. Structurally simple and easy to use threaded connection of drill pipes is applicable in the construction of highly curved and horizontal wells by increasing the torsion moment.

Description

The claimed utility model (PM) relates to the field of mining, namely to drill pipes, including thick-walled and weighted pipes, downhole mechanisms (packers, jars, etc.) used in drilling, emergency operations and well workover.

The weakest element of most types of drill pipe is their threaded joint (PC), whose torsional and bending strengths are generally weaker than the pipe body. Therefore, the industry uses the design of pipes with threaded grooves that reduce the stress concentration in the dangerous sections of the thread, and with threaded ends balanced for bending according to the criterion of Wm / Wn, where

Wm - moment of resistance of the coupling;

Wн is the moment of resistance of the nipple.

The threaded joint of the drill pipe is considered balanced for bending, if the ratio Wm / Wn is in the range of 2.3-2.7.

Threads are also used whose profile angle (angle at the top of the thread) is 90 degrees. A thread with a profile angle of 90 degrees, ceteris paribus, transmits a high torsion moment.

In order to increase the torsion moment of the locking thread without simultaneously increasing the outer diameter of the lock and reducing its internal hole, PC with a second internal stop is widely used in drilling practice, in which the end of the threadless section behind the small base of the threaded cone of the nipple additionally abuts against a special ledge in the coupling. There are several PC designs with two stops (external and internal), which use threads with a taper of 1: 6, 1: 8, 1:16, with a pitch equal to 6.35-8.47 mm, and a profile angle of 60 and 90 degrees. The length of the threaded section of the nipple ranges from 9.6 to 25.4 mm and is made with an external cylindrical or conical surface, the angle of inclination of the latter is assumed constant over the entire length. In locks with an enlarged internal hole, the wall thickness of the thrust belt decreases and, as a result, the axial compressive load and the torsion moment are reduced. [Grant Prideko. Drill Pipe data tables. All rights reserved. December, 2003, http://www.oilproduction.net].

A known construction of the connection of the drill string [patent for utility model RU No. 88729, prior. 01/11/2009 publ. 01/10/2010. Bull. No. 1], including a tapered thread provided with internal and external stops, and the internal stop is made of at least 10 mm In the connection of the drill string with two stops, a widespread standard thread was used, the taper of which is 1: 6, pitch - 6.35 mm, profile angle - 60 degrees. In patent No. 88729, a kinematic diagram of a known connection of drill pipes with two threaded stops is given. The inner stop belt and the counterbore in the sleeve along the entire length are conical in shape with a constant angle of inclination corresponding to the angle of inclination of the thread.

Known PC design with trapezoidal thread, the pitch of which is 8.47 mm, the taper is 1: 9.6, the profile angle is 90 degrees, made with two stops [patent on PM RU No. 134570, prior. 05/07/2013, published. November 20, 2013, Byul. 32]. The slope angle of the conical outer surface of the thrust band corresponds to the slope angle of the thread surface. An optimally balanced PC with a taper of 1: 9.6 has limited use, since it is designed for locks with a diameter of 100 and 108 mm, used in wells with a diameter of 120.6-151.0 mm, i.e. in small diameter wells.

The closest to the claimed PM in terms of features is a PC with two stops with a standard thread 3-94 (NC - 35), the pitch of which is 6.35 mm, taper -1: 6 [patent for PM RU No. 114087, prior. 08/03/2014, publ. 03/10/2012, Bull. No. 7]. In PM No. 114087, the outer diameter of the lock is at most 123 mm, the inner diameter is at least 50 mm. The stop band in the PC with two stops along the entire length is made in the form of a cone with a slope angle corresponding to the slope angle of the internal thread of the coupling. The disadvantage of this PC is the low compression resistance of the thrust belt. Due to the outer diameter limitation, it is impossible to use PC when working in wells with a diameter of more than 165.1 mm.

The technical result of the claimed utility model is to increase the torsion moment of the threaded connection.

The technical result is ensured by the fact that in a threaded connection of drill pipes, including nipple and socket ends with a trapezoidal tapered thread, with external and internal stops, according to a utility model, the internal stop of the nipple end has conical and cylindrical sections, and the inner bore in the sleeve end has a torroidal pocket.

The specified technical result is achieved due to the fact that the outer surface of the inner stop of the nipple end has conical and cylindrical sections, which allows to increase the outer diameter and wall thickness of the stop, and accordingly the surface area of the stop. This in turn proportionally increases the torsional moment of the threaded connection. The torroidal pocket in the inner bore of the coupling end provides a tighter connection of the plane of the inner stop with the increased plane of the inner stop of the nipple end due to the additionally formed cavity where solid particles of sludge and the like, which can be on the plane of the stop, are moved together with an increased amount of lubricant , which in turn allows you to reduce stress on the threaded joint stop and increase torque.

The figure 1 presents a threaded connection.

The figure 2 presents an enlarged image of the internal emphasis of the threaded connection.

The figure 3 presents the table "Parameters and characteristics of threaded connections BT (thread: pitch - 8.47 mm; taper - 1: 9.6; profile angle - 90 degrees with two stops and the design of the internal stop according to the declared PM) - line 1; 2; 3; four; 5 and thread with one external stop - line 6 ".

The figure 4 presents the table "Parameters and characteristics of threaded connections BT (thread according to GOST R 50864-96 with two stops and the design of the internal stop according to the stated PM) - line 1; 2; 3; 4 and thread according to GOST R 50864-96 with one stop - line -5 ".

The design of the threaded connection is shown in the drawing of FIG. one.

In FIG. 1 shows a threaded connection, consisting of a nipple end 1 connection, a coupling end 2 connections, a tapered trapezoidal thread 3, internal 4 and external 5 stops, the indicated designations: lр - length of thread, lon - distance from the plane of the external stop to the main plane s, D is the outer diameter of the PC, d is the inner diameter of the PC.

In FIG. 1 shows a threaded connection screwed to the contact of the planes of the outer 5 and inner 4 stops.

The design of the internal stop of the threaded connection is shown in FIG. 2.

конического 10 длиной а и цилиндрического 11 участка внутреннего упора ниппельного конца, угол внутреннего ниппельного упора 12 с радиусом притупления

указанные обозначения: dpn - наружный диаметр внутреннего упора ниппельного конца в плоскости торца, lр - длина трапецеидальной конической резьбы, ф - угол уклона резьбы и конического участка внутреннего упора ниппельного конца.In FIG. 2 shows an enlarged image of an internal stop of a threaded joint, consisting of an internal stop of a nipple end 6, an internal stop of a sleeve end 7, a cylindrical bore 8, a toroidal pocket 9 with a radius

conical 10 of length a and cylindrical 11 of the inner stop of the nipple end, the angle of the inner nipple stop 12 with a blunting radius

indicated designations: dpn is the outer diameter of the internal stop of the nipple end in the end plane, lр is the length of the trapezoidal conical thread, f is the angle of the thread and the conical section of the internal stop of the nipple end.

In FIG. 2 shows the design of the internal stop of the threaded connection: the outer surface of the nipple end 6 has a conical section 10 of length a with a slope angle f and a cylindrical section 11, which allows to increase the outer diameter dpn and, accordingly, the surface area of the internal stop of the nipple end 6, which increases the torsion moment of the threaded connection.

во внутреннем упоре муфтового конца 7 обеспечивает более плотное соединение с увеличенной плоскостью поверхности внутреннего упора ниппельного конца 6. Твердые частицы шлама и т.п., которые могут находиться на плоскости упорного уступа муфтового конца 7 при докреплении резьбового соединения вместе со смазкой могут перемещаться в тороидальный карман 9 и внутреннее отверстие соединения d, что снижает возможность повреждения плоскостей ниппельного конца 6 и муфтового конца 7 внутреннего упора, что снижает напряжения и повышает момент кручения резьбового соединения.The toroidal annular pocket 9 forms an additional cavity with a radius

in the inner stop of the coupling end 7 provides a more tight connection with the increased plane of the surface of the inner stop of the nipple end 6. Solid particles of sludge and the like, which can be on the plane of the thrust ledge of the coupling end 7 when attaching the threaded connection together with the grease can move into a toroidal pocket 9 and the inner hole of the connection d, which reduces the possibility of damage to the planes of the nipple end 6 and the coupling end 7 of the internal stop, which reduces stress and increases the moment steeper Ia threaded connection.

In FIG. 3, the table optionally gives examples of the main design parameters and the PC Z2-99 characteristic; Z2-105; Z2-119; Z2-130; Z2-83 with two stops and the design of the internal stop according to the declared PM - lines 1-5, and PC Z-130 with one stop - lines 6.

In FIG. 4, the table optionally gives examples of the main design parameters and the PC Z2-102 characteristic; Z2-108; Z2-122; Z2-133 with a thread according to GOST R 50864-96 with two stops and an internal stop design according to the stated PM line 1-4, and for comparison of torsion moment values, line 5 contains PC data with a Z-133 thread according to GOST R 50864-96 with one external focus. The tensile stresses Qpc and the torsion moment Mkr.rs in the tables in figures 3 and 4 are given for PC made of steel, the yield strength of which is equal to 758 N / mm2.

As can be seen from the values in the tables, the torsion moment, for example, of a PC with a double-threaded thread Z2-130 with an internal stop design according to the declared PM, is 1.54 times (108.8 / 70.4 = 1.54) higher than the torsion moment of a single-stop PC with standard thread Z-130. The torsion moment of a two-stop PC with a standard profile thread Z2-133 with an internal stop design according to the declared PM exceeds the torsion moment of a single-stop PC with a standard thread Z-133 by 1.4 times (89.2 / 63.7 = 1.4).

Thus, the use of structural elements in the form of conical and cylindrical sections of the internal stop of the nipple end, the internal threaded bore of the sleeve end in the form of a torroid pocket, ceteris paribus, allows us to successfully build horizontal and highly curved wellbores with a greater distance from the main vertical wellbore due to increase the torque of the threaded connection.

According to the manufacturing method, the threaded connections declared in the PM do not differ from the manufacturing method of standard PCs; therefore, the use of special technologies and equipment is not required.

Thus, PM allows you to increase the torsion moment of the threaded connection of the drill pipe.

Claims (1)

A threaded connection of drill pipes, including the nipple and sleeve ends with a trapezoidal tapered thread, with external and internal stops, characterized in that the internal stop of the nipple end has conical and cylindrical sections, and the internal bore in the sleeve end has a toroidal pocket.

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