CN2451715Y

CN2451715Y - Petroleum casing and oil-pipe high-pressure air sealing coupling structure

Info

Publication number: CN2451715Y
Application number: CN 00244669
Authority: CN
Inventors: 施太和; 陈良浩; 林元华; 黄万志
Original assignee: Southwest Petroleum University
Current assignee: Southwest Petroleum University
Priority date: 2000-10-12
Filing date: 2000-10-12
Publication date: 2001-10-03
Anticipated expiration: 2010-10-12

Abstract

The utility model relates to a high-pressure air sealing coupling structure of petroleum casing pipes and oil pipes, which comprises a casing pipe (or an oil pipe) with external conical buttress threads, and a coupling clamp with internal conical buttress threads. A sealing ring is arranged between the end of the casing pipe (or the oil pipe) and the coupling clamp, and the high-pressure air sealing is ensured by high contact stress on the contacting surfaces of the sealing ring, the casing pipe (or the oil pipe) and the coupling clamp. The height of the crest of a full screw thread section of the casing pipe (or the oil pipe) is properly decreased. Thus, the contact stress between the casing pipe and the coupling clamp and the circumferential stress in the coupling clamp are reduced, and stress corrosion in an acidic gas well is avoided. The structure can be manufactured by a home-made numerical control lathe, and can be used in a high-pressure natural gas well with H2S gas or without H2S.

Description

A kind of petroleum casing pipe and oil pipe high pressure gas sealed attachment structure

The utility model relates to the draw bail of petroleum casing pipe and oil pipe, particularly high pressure gas sealed attachment structure.

At present, the draw bail that is adopted in the connection of petroleum casing pipe and oil pipe both at home and abroad normally processes buttress thread on the conical surface of the outer garden of sleeve pipe and oil pipe end, links with the buttress thread of box cupling inner surface.For it can not leaked under the high pressure effect of oil, natural gas, the external screw thread end is provided with end face, the garden conical surface etc., and by metal and Metal Contact sealing, the requirement on machining accuracy of double thread and hermetically-sealed construction is very high simultaneously.China does not also have producer can formally produce this high pressure gas Sealed casing pipe (or oil pipe) and box cupling by batch at present, but by from external import, costs an arm and a leg, and expends a large amount of foreign exchanges of country.Along with China's development of the West Regions and " enforcement of West-east Gas engineering; external businessman may seize the opportunity the price that improves high pressure gas Sealed casing pipe and oil pipe, therefore press for design that a kind of China can processing and also can satisfy sleeve pipe and the oil pipe high pressure gas hermetically-sealed construction that oil field development requires.

The purpose of this utility model is, propose a kind ofly can reach the oil field instructions for use, and machining accuracy is not high comparatively speaking, the sleeve pipe that can process with the higher Digit Control Machine Tool of precision in China existing machinery factory and the high pressure gas sealed attachment structure of oil pipe.

For achieving the above object, the utility model adopts following scheme:

This hermetically-sealed construction comprises sleeve pipe or the oil pipe (1) with outer garden awl buttress thread, the box cupling (2) with interior garden awl buttress thread, the two cooperatively interacts, and it is characterized in that: be provided with joint ring (3) between sleeve pipe or externally threaded end of oil pipe (1) and box cupling (2).In the end of sleeve pipe or oil pipe (1), the place ahead of taper thread has processed a garden conical surface (4) and step (5); The place ahead of the taper thread ending part of box cupling (2) near in the endoporus in box cupling centre position, has processed annular surface (6) and step (7); The inner conical surface of joint ring (3) matches with the garden conical surface (4) of sleeve pipe or oil pipe (1), and external surface cooperates with the annular surface (6) of box cupling (2), and two end face contacts with the step (5) of sleeve pipe or oil pipe (1) and the step (7) of box cupling (2) respectively.

The size of joint ring (3) and distortion should be passed through accurate Calculation, and its size and distortion should be enough to guarantee that its four sides is uniform-compression basically after whole connection tightens, and produce enough big surface contact stress to prevent high pressure gas leakage.The annular surface (6) of the garden conical surface (4) of sleeve pipe or oil pipe (1), step (5) and box cupling (2) and the size and the distortion of step (7), also should pass through accurate Calculation, make it be enough to guarantee on request joint ring (3) to be compressed from radial and axial, obtain needed surface contact stress.

The crest height of aspect ratio API (American Petroleum Institute (API)) the standard buttress thread of the last full threaded section crest of buttress thread of sleeve pipe or oil pipe (1) is lower slightly, to reduce the contact pressure between sleeve pipe or oil pipe (1) and the box cupling (2), help improving the reliability of box cupling (2) work, and help in acid gas well, preventing stress corrosion cracking.

The utility model has the advantages that:

(1) owing between sleeve pipe or oil pipe (1) and box cupling (2), is provided with joint ring (3), the large deformation of joint ring can remedy the deficiency of machining accuracy, thereby the machining accuracy that connects screw thread can reduce relatively, can in China existing machinery factory, process, thereby can reduce from external import, save foreign exchange.

(2) the suitable reduction of the crest height of full threaded section in the external screw thread of sleeve pipe or oil pipe (1), after sleeve pipe and box cupling tighten, the contact stress that forms between the thread bottom surface of the thread end face of sleeve pipe or oil pipe (1) and box cupling (2) is lower, thereby reduced the inner circumferential stress of box cupling (2), helped improving the functional reliability of box cupling (2) and help in acid gas well, preventing stress corrosion cracking.

(3) accurate calculating all passed through in the size of joint ring (3), distortion and the each several part size that contacts with joint ring (3), distortion, is enough to guarantee to obtain the surface contact stress of needs, reaches seal request, satisfies the needs of oil gas well development.

Description of drawings is as follows:

Fig. 1 is the schematic diagram of assembling drawing of the present utility model;

Fig. 2 is the schematic diagram of the enlarged drawing of joint ring and sleeve pipe (or oil pipe) and box cupling junction;

Fig. 3 is the sectional drawing of joint ring.

Below in conjunction with description of drawings embodiment of the present utility model:

This hermetically-sealed construction comprises the sleeve pipe (or oil pipe) (1) with outer garden awl buttress thread, the box cupling (2) with interior garden awl buttress thread, and the two cooperatively interacts, and is provided with joint ring (3) between sleeve pipe or externally threaded end of oil pipe (1) and box cupling (2).The height of the standard buttress thread crest of the crest aspect ratio API (American Petroleum Institute (API)) of the full threaded section of buttress thread on the sleeve pipe (or oil pipe) (1) is lower slightly, so that after sleeve pipe (1) and box cupling (2) tighten, between full thread form end face of sleeve pipe (1) and box cupling (2) tooth bottom surface, only form lower pressure, thereby reduce the inner circumferential stress of box cupling (2), help improving the functional reliability of box cupling (2), and help in acid gas well, preventing stress corrosion cracking.Referring to Fig. 2, A is the little path position of API buttress thread, and B is a path position in the API buttress thread, and C is the big path position of API buttress thread, and C ' is the actual big path position that adopts of this hermetically-sealed construction.

The end of sleeve pipe (or oil pipe) (1), the place ahead of taper thread has processed a garden conical surface (4) and step (5), and the place ahead of the taper thread ending part of box cupling (2) near in the endoporus in box cupling centre position, has processed annular surface (6) and step (7).The inner conical surface of joint ring (3) matches with the garden conical surface (4) of sleeve pipe (or oil pipe) (1), external surface cooperates with the annular surface (6) of box cupling (2), two end face respectively with the step (5) of sleeve pipe (or oil pipe) (1) and the step of box cupling (2)) (7) contact.

The size of joint ring (3) and distortion should be passed through accurate Calculation, and its size and distortion should be enough to guarantee that its four sides is uniform-compression basically after whole connection tightens, and produce enough big contact stress to prevent high pressure gas leakage.The annular surface (6) of the garden conical surface (4) of sleeve pipe (or oil pipe) (1), step (5) and box cupling (2), the size and the distortion of step (7), also should pass through accurate Calculation, make it be enough to guarantee on request joint ring (3) to be compressed from radial and axial, to obtain needed surface contact stress.Joint ring (3) can adopt metal material or macromolecular material manufacturing.

This hermetically-sealed construction is machine making factory's higher lathe in machining of precision at home.

Claims

1. petroleum casing pipe and oil pipe high pressure gas sealed attachment structure, comprise sleeve pipe or the oil pipe (1) with outer garden awl buttress thread, box cupling (2) with interior garden awl buttress thread, the two cooperatively interacts, and it is characterized in that: be provided with joint ring (3) between sleeve pipe or oil pipe (1) external screw thread end and box cupling (2).

2. petroleum casing pipe according to claim 1 and oil pipe high pressure gas sealed attachment structure, it is characterized in that: the end of sleeve pipe or oil pipe (1), the place ahead of taper thread, a garden conical surface (4) and step (5) have been processed, the place ahead of the taper thread ending part of box cupling (2), near in the endoporus in box cupling centre position, annular surface (6) and step (7) have been processed, the inner conical surface of joint ring (3) matches with the garden conical surface (4) of sleeve pipe or oil pipe (1), external surface cooperates with the annular surface (6) of box cupling (2), and two end face contacts with the step (5) of sleeve pipe or oil pipe (1) and the step (7) of box cupling (2) respectively.

3. petroleum casing pipe according to claim 1 and oil pipe high pressure gas sealed attachment structure is characterized in that: the crest height of the aspect ratio API standard buttress thread of the last full threaded section crest of buttress thread of sleeve pipe or oil pipe (1) is lower slightly.