CN201202413Y

CN201202413Y - Drill rod joint with good anti-torque performance

Info

Publication number: CN201202413Y
Application number: CNU2008200567197U
Authority: CN
Inventors: 袁鹏斌; 王广群; 帅亚民; 周永其
Original assignee: SHANGHAI HAILONG PETROLEUM PIPE MATERIAL INSTITUTE
Current assignee: SHANGHAI HAILONG PETROLEUM PIPE MATERIAL INSTITUTE
Priority date: 2008-03-28
Filing date: 2008-03-28
Publication date: 2009-03-04
Anticipated expiration: 2018-03-28

Abstract

The utility model relates to the technical field of thread connection of oil well pipes, in particular to a drill rod connector with good anti-torque performance, which is composed of a first shoulder and an inner thread piece of an inner thread, a second shoulder and an outer thread piece of an outer thread. The connector is characterized in that the first shoulder is an end surface shoulder whose end surface has an angle of fifteen degrees with the radial surface of the inner thread piece, the second shoulder is a torque shoulder which has an angle of fifteen degrees with the radial surface of the outer thread piece, and the first shoulder is matched with the second shoulder with each other. The connector mainly solves the technical problems of an existing product that requirements to the manufacturing accuracy are very high, guaranteeing the two shoulders being connected at the same time has certain difficulty, and the anti-torque performance and the sealing performance of the drill rod connector are obviously improved.

Description

The well behaved tool joint of a kind of torque resistant

Technical field

The utility model relates to and belongs to oil well pipe thread link technique field, the well behaved tool joint of especially a kind of torque resistant.

Background technology

Oil drill rocker is recovery of subterranean oil or the necessary instrument of natural gas, and nipple is the important component part of drilling rod, is the critical component that drilling rod is one by one coupled together.The tool joint work under bad environment, the stressing conditions complexity is very easy to take place the inefficacy of forms such as thread root ruptures, the burn into screw thread pierces through.The tool joint of using at present, the overwhelming majority is the API standard tool joint, this joint is produced and check according to API standard (API SPEC 7), every performance indications will meet the requirement of API standard (API RP 7G), its advantage is a technology maturation, belongs to standard component, and interchangeability is good, but also there are a lot of defectives simultaneously, cause joint area that failure accidents takes place easily.

The structural representation of API tool joint is seen accompanying drawing 1, and its screw thread form is seen accompanying drawing 2.This tool joint is made of jointly inner thread piece and external thread piece, and its connecting thread belongs to taper pipe thread, is the round thread form, and spigot surface angle and bearing surface angle all are 30 °.Because the bearing surface angle of this screw thread is milder, when joint is subjected to axial tension or compressive load is done the time spent, can produce very big radial component, this radial component swells the joint internal thread, external screw thread shrinks, and the bonding strength of butt joint, stress concentration degree all can bring very adverse influence.When API tool joint during in tight condition, internal thread end face and externally threaded shoulder interact, produce very big reaction force, this reaction force mainly relies near a few tooth thread engagements of extruding of shoulder and bears, the very big axial force that made herein threads carry, under the effect of this axial force, the trend that internal thread swells is very obvious, especially when abnormal conditions in drilling process, occurring, the moment of torsion that joint bears has exceeded the prescribed torque scope, this moment, internal thread produced very big circumferential tensile stress, was easy to take place stress corrosion cracking, even the failure accidents of bloated button of internal thread and the fracture of external screw thread root takes place.

In order to remedy the above-mentioned defective of API drilling rod, the Chinese patent publication number is CN2734974Y, and open day is on October 19th, 2005, and the utility model patent name is called " high antitorque tool joint ", has provided a kind of tool joint that can strengthen the drilling rod anti-twisting property.This joint is made up of male connection and the female adapter that is threaded with it, its improvements are that the root circular bead surface of male connection and screw thread end face closely cooperate with the screw thread end face and the root circular bead surface of female adapter internal thread respectively, form two shoulder structures.These two shoulders are shared the moment of torsion that joint is born jointly, rather than are born separately by a shoulder.Like this, the region of stress concentration of API drilling rod is positioned at internal thread end face and interaction place of externally threaded shoulder, and the region of stress concentration of this novel joint then is dispersed into two by one, thereby the stress maximum value is obviously descended.Studies show that, by being designed to the method for two shoulder structures, reducing the stress of tool joint and concentrate, reduce because of the pernicious circumferential stress that the joint internal thread swells and the external screw thread contraction causes, is more effective.Therefore, Chinese patent CN2670579Y, CN280919Y, CN200943450Y etc. are the modes that adopts two shoulders.But the shortcoming and defect part of this joint is: very high to requirement on machining accuracy, guarantee that two circular bead surfaces contact simultaneously, have certain degree of difficulty.

The utility model content

The purpose of this utility model is to provide a kind of torque resistant well behaved tool joint, it is very high to requirement on machining accuracy mainly to solve existing product, guarantee that two circular bead surfaces contact simultaneously, the technical problem that certain degree of difficulty is arranged, the torsional property of this tool joint, sealing performance all have obvious enhancing.

For solving the problems of the technologies described above, technical scheme of the present invention is:

The well behaved tool joint of a kind of torque resistant, it is by the inner thread piece with first shoulder and internal thread and have second shoulder and externally threaded external thread piece constitutes, it is characterized in that: the sagittal plane that this first shoulder is end face and inner thread piece is the end face shoulder of 15 ° of angles, the sagittal plane that this second shoulder is circular bead surface and external thread piece is the torque shoulder of 15 ° of angles, and first shoulder and second shoulder mate mutually.

The well behaved tool joint of described torque resistant is characterized in that: internal thread and externally threaded profile are barb-shaped, and its spigot surface angle is 30～45 °, and the bearing surface angle is 0～-9 °, thread taper 1:6～1:8, pitch 4 teeth/25.4mm, tooth depth 2.8mm.

The well behaved tool joint of described torque resistant is characterized in that: first shoulder and second shoulder all are reverse shoulders.

Compared with prior art, the beneficial effects of the utility model are:

1) to have adopted thread forms be the special thread form of fluking type to the utility model, avoided pernicious generation radially, and joint efficiency significantly improves;

2) the utility model is owing to adopted reverse torque shoulder, and the torsional property of joint, sealing performance all have obvious enhancing.

Description of drawings

Fig. 1 is an API standard tool joint schematic diagram.

Fig. 2 is an API standard tool joint form of thread schematic diagram.

Fig. 3 is a structural representation of the present utility model.

Fig. 4 is a form of thread schematic diagram of the present utility model.

The specific embodiment

See also Fig. 3,4, it is the well behaved tool joint of a kind of torque resistant of the utility model, and it is made of inner thread piece 1 with first shoulder 3 and internal thread 2 and external thread piece 4 with second shoulder 5 and external screw thread 6.First shoulder 3 and second shoulder 5 all are reverse shoulders.This first shoulder 3 is end face shoulders that the sagittal plane of end face and inner thread piece 1 is 15 ° of angles, and this second shoulder 5 is torque shoulder that the sagittal plane of circular bead surface and external thread piece 4 is 15 ° of angles, and first shoulder 3 and second shoulder 5 mate mutually.The profile of internal thread 2 and external screw thread 6 is barb-shaped, and its spigot surface angle is 30～45 °, and the bearing surface angle is 0～-9 °, thread taper 1:6～1:8, pitch 4 teeth/25.4mm, tooth depth 2.8mm.

Come further to understand characteristics of the present utility model by the following examples:

Embodiment 1 is the drilling rod that is used for Φ 73.03 * 9.19mm10.41b/ft, and grade of steel is G105.The material of joint adopts the API standard material, and its yield strength is 827.4MPa.The screw thread spigot surface angle α of this utility model tool joint=45 °, the bearing surface angle is β=-3 °.Thread taper 1:6, pitch 4 teeth/25.4mm, tooth depth 2.8mm.Compare with adopting common API form of thread V-0.038R, guaranteeing that under the identical situation in the inside and outside footpath of joint, the maximum of joint allows torque wrench moment to bring up to about 27600N-m from 22975N-m, can improve about 1.2 times.According to the result of calculation of contact pressure, the hermetic seal ability of joint also can improve about 1.3 times.

Embodiment 2 is the drilling rods that are used for Φ 127 * 9.19mm19.51b/ft, and grade of steel is S135.The material of head adopts the API standard material, and its yield strength is 827.4MPa.The screw thread spigot surface angle α of this utility model tool joint=30 °, the bearing surface angle is β=-3 °.Thread taper 1:8, pitch 4 teeth/25.4mm, tooth depth 2.8mm.Compare with adopting common API form of thread V-0.038R, guaranteeing that under the identical situation in the inside and outside footpath of joint, the maximum of joint allows torque wrench moment to bring up to about 111700N-m from 85966N-m, can improve about 1.3 times.According to the result of calculation of contact pressure, the hermetic seal ability of joint also can improve about 1.3 times.

Being preferred embodiment of the present utility model only in sum, is not to be used for limiting practical range of the present utility model.Be that all equivalences of doing according to the content of the utility model claim change and modification, all should be technology category of the present utility model.

Claims

1, the well behaved tool joint of a kind of torque resistant, it is by the inner thread piece (1) with first shoulder (3) and internal thread (2) and have second shoulder (5) and the external thread piece (4) of external screw thread (6) formation, it is characterized in that: this first shoulder (3) is the end face shoulder that the sagittal plane of end face and inner thread piece (1) is 15 ° of angles, this second shoulder (5) is the torque shoulder that the sagittal plane of circular bead surface and external thread piece (4) is 15 ° of angles, and first shoulder (3) mates mutually with second shoulder (5).

2, the well behaved tool joint of torque resistant according to claim 1 is characterized in that: the profile of internal thread (2) and external screw thread (6) is barb-shaped, and its spigot surface angle is 30～45 °, the bearing surface angle is 0～-9 °, thread taper 1:6～1:8, pitch 4 teeth/25.4mm, tooth depth 2.8mm.

3, the well behaved tool joint of torque resistant according to claim 1 and 2 is characterized in that: first shoulder (3) and second shoulder (5) all are reverse shoulders.