CN203531776U

CN203531776U - Economical torsion-resistant oil casing pipe screwed joint

Info

Publication number: CN203531776U
Application number: CN201320625757.0U
Authority: CN
Inventors: 杨林
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-10-11
Filing date: 2013-10-11
Publication date: 2014-04-09
Anticipated expiration: 2023-10-11

Abstract

The utility model relates to an economical torsion-resistant oil casing pipe screwed joint. The economical torsion-resistant oil casing pipe screwed joint comprises a coupling (1) and more than two outer threaded pieces (3), wherein internal threads (2) are machined on the coupling (1), and external threads (4) are machined on the outer threaded pieces (3). The economical torsion-resistant oil casing pipe screwed joint is characterized in that when the joint is used, the internal threads (2) are meshed with the outer threads (4), torque shoulders (5) which abut against each other are arranged at the ends of the two outer threaded pieces (3) respectively, and the torque shoulders (5) tightly abut against each other after the joint is tightly screwed. The economical torsion-resistant oil casing pipe screwed joint has the advantages that gaps between pipe ends inside the coupling are eliminated, and the machining cost of the threads is far lower than the machining cost of special threads and is equal to the machining cost of buttress threads.

Description

Economical antitorque oil bushing threaded connector

Technical field

The utility model relates to a kind of oil bushing threaded connector, relates in particular to a kind of economical antitorque oil bushing threaded connector, belongs to oil pipe thread link technique field.

Background technology

Tubing and casing is the necessary oil country tubular good of recover petroleum and natural gas, and hundreds of root tubing and casing is threaded connection, and forms the tubing string that reaches thousands of meters, bears the task of recover petroleum and natural gas.Connecting thread mainly contains two kinds of forms at present, and a kind of is API screw thread, and a kind of is special thread.API screw thread is according to the thread forms of API standard production and use.This nipple is according to API standard manufacture, and technology maturation is processed easy to detectly, and cost is lower, is therefore applied widely.

After API screw thread is tightened, between the inner pipe end of box cupling and pipe end, having distance is the gap of M, generally, and M=25.4mm.The existence in this gap is that the structure by API screw thread determines.Existence due to machining tolerance, the position of tightening of different joints changes, in order to prevent that two external thread piece contacts that are screwed into box cupling two ends are (after contact, tightening of one end can cause the loosening of the other end, thereby further affect the switching performance of joint), it is necessary that the buffer area that a distance is M is set.Due to the existence in this gap, while causing oil or natural gas to flow, produce turbulent flow in pipe, cause erosion corrosion.

Special threading connector has improved thread forms, has increased metal/metal hermetically-sealed construction, and its object is generally to improve sealing performance and the torsional property of joint.Such as, China Patent Publication No. is CN2575286Y, and in open day on September 24th, 2003, utility model name is called " oil bushing threaded connector ", and this patent discloses a kind of oil bushing threaded connector with good seal performance.This nipple is formed by connecting by screw thread 1 by external thread piece P and inner thread piece B.Be characterized in that external thread piece front end is provided with one column sealed, the correspondence position of inner thread piece is provided with a protruding sphere primary sealing area, and the two interference fit, seals.Meanwhile, external thread piece front end face is changed into-9 or-15 ° of angles, form interference fit with-9 or-15 ° of shoulders of inner thread piece.Like this, not only the bonding strength of joint, sealing performance are improved, and have also eliminated the gap existing between the inner pipe end of box cupling and pipe end simultaneously.But the processing request of special thread is high, be the patent of each producer, expensive, be not suitable for real estate oil field.Meanwhile, special thread cannot exchange completely with API screw thread, and inconvenient oil field is used.

Summary of the invention

The purpose of this utility model is to overcome above-mentioned deficiency, provide a kind of and eliminated the gap existing between the inner pipe end of box cupling and pipe end, and screw thread processing cost is far below special thread, the economical antitorque oil bushing threaded connector suitable with API buttress thread.

The purpose of this utility model is achieved in that

A kind of economical antitorque oil bushing threaded connector, it comprises a box cupling and two external thread pieces, on described box cupling, be processed with internal thread, on described external thread piece, be processed with external screw thread, when joint uses, internal thread and external screw thread intermesh, and the end of two external thread pieces is respectively arranged with the torque shoulder on mutual top, and joint is tightened rear torque shoulder and held out against mutually.

Preferably internal thread and externally threaded screw thread bearing surface angle are negative value as a kind of, spigot surface angle be on the occasion of, be shaped as barb-shaped.Internal thread and external screw thread adopt same tapering Z, pitch P, tooth depth h, and spigot surface angle α, bearing surface angle β, different according to specification, different tapering Z, pitch P, tooth depth h and bearing surface angle β are set, concrete numerical value is as follows:

60.3≤OD≤114.3mm, Z=1/16, P=3.175mm, h=0.86, β=-5 °; 114.3 <OD≤177.8mm, Z=1/12, P=5.08mm, h=1.27mm, β=-7 °; 177.8 <OD≤339.7mm, Z=1/12, P=6.35mm, h=1.75, β=-7 °; 339.7<OD≤508.0mm, Z=1.25/12, P=8.47mm, h=2.15mm, β=-10 °, for different specifications, the spigot surface angle of screw thread is constant, α=20 °.

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

1, by the torque shoulder on mutual top is set, eliminated the gap existing between the inner pipe end of box cupling and pipe end, improved anti-twisting property and the resistance to compression of joint;

2, the partially trapezoidal joint of processing cost and common API is suitable, far below Special threading connector.

Therefore the utlity model has and eliminated the gap existing between the inner pipe end of box cupling and pipe end, and screw thread processing cost is far below special thread, the advantage suitable with API buttress thread.

Accompanying drawing explanation

Fig. 1 is the structural representation of the economical antitorque oil bushing threaded connector of the utility model.

Fig. 2 is internal thread and the externally threaded structural representation of the economical antitorque oil bushing threaded connector of the utility model.

Wherein:

Box cupling 1, internal thread 2, external thread piece 3, external screw thread 4

Pitch P, tooth depth h, spigot surface angle α, bearing surface angle β.

The specific embodiment

Referring to Fig. 1 ~ Fig. 2, a kind of economical antitorque oil bushing threaded connector that the utility model relates to, it comprises a box cupling 1 and two external thread pieces 3.On described box cupling 1, be processed with internal thread 2, on described external thread piece 3, be processed with external screw thread 4, when joint uses, internal thread 2 intermeshes with external screw thread 4, plays connection function.The end of two external thread pieces 3 is respectively arranged with the torque shoulder 5 on mutual top, and joint is tightened rear torque shoulder 5 and held out against mutually, plays antitorque effect.This screw thread bearing surface angle is negative value, spigot surface angle be on the occasion of, make to be shaped as barb-shaped, there is certain sealing function, difficulty of processing is suitable with API buttress thread.Corresponding different tubing and casing specifications, arranges different pitch, tooth depth and tapering, makes joint joint when specification is larger also be not easy random button, and make-up speed is very fast, and make-up is easy.

Specific as follows: internal thread 2 and external screw thread 4 adopt same tapering Z, pitch P, tooth depth h, spigot surface angle α, bearing surface angle β, according to specification (external diameter represents with OD) difference, different tapering Z, pitch P, tooth depth h and bearing surface angle β are set, and concrete numerical value is as follows:

60.3≤OD≤114.3mm，Z=1/16，P=3.175mm，h=0.86，β=-5°；114.3?<OD≤177.8mm，?Z=1/12，P=5.08mm，h=1.27mm，β=-7°；177.8?<OD≤339.7mm，?Z=1/12，P=6.35mm，h=1.75，β=-7°；339.7<OD≤508.0mm，?Z=1.25/12，P=8.47mm，?h=2.15mm，?β=-10°。For different specifications, the spigot surface angle of screw thread is constant, α=20 °.This efficiency that is threaded is high, has certain sealing function simultaneously.

This kind of economical antitorque oil bushing threaded connector is named as DL-HB.

First embodiment of the design is the oil pipe for Ф 73.0 * 7.01 mm, and grade of steel is P110.The external diameter of external thread piece 3 is 73.0 mm, and the external diameter of box cupling 1 is 88.9mm, and coupling length is 130.2mm.Thread pitch is 8 teeth/25.4mm(3.175mm), tapering 1:16, tooth depth 0.86mm, bearing surface angle-5 °, 20 °, spigot surface angle.This joint anti-twisting property reaches 1.5 times of common API joint, and hydraulic seal ability reaches 127.4MPa, and hermetic seal ability reaches 101.9MPa.

Second embodiment of the design is the sleeve pipe for Ф 406.4 * 16.66 mm, and grade of steel is N80.The external diameter of external thread piece 3 is 406.4 mm, and the external diameter of box cupling 1 is 431.8mm, and coupling length is 266.9 mm.Thread pitch is 3 teeth/25.4mm(8.467mm), tapering 1.25:12, tooth depth 2.15mm, bearing surface angle-10 °, 20 °, spigot surface angle.This joint anti-twisting property reaches 1.5 times of common API joint, and hydraulic seal ability reaches 39.6MPa, and hermetic seal ability reaches 27.7MPa.

Claims

1. an economical antitorque oil bushing threaded connector, it comprises a box cupling (1) and two external thread pieces (3), on described box cupling (1), be processed with internal thread (2), on described external thread piece (3), be processed with external screw thread (4), while it is characterized in that joint uses, internal thread (2) intermeshes with external screw thread (4), and the end of two external thread pieces (3) is respectively arranged with the torque shoulder (5) on mutual top, and joint is tightened rear torque shoulder (5) and held out against mutually.

2. a kind of economical antitorque oil bushing threaded connector according to claim 1, is characterized in that internal thread (2) and the screw thread bearing surface angle of external screw thread (4) are negative value, spigot surface angle be on the occasion of, be shaped as barb-shaped.

3. a kind of economical antitorque oil bushing threaded connector according to claim 2, it is characterized in that internal thread (2) and external screw thread (4) adopt same tapering Z, pitch P, tooth depth h, spigot surface angle α, bearing surface angle β, different according to specification, different tapering Z, pitch P, tooth depth h and bearing surface angle β are set, concrete numerical value is as follows: