CN201103349Y - Screwed tie-in of oil casing tube - Google Patents
Screwed tie-in of oil casing tube Download PDFInfo
- Publication number
- CN201103349Y CN201103349Y CNU2007200277062U CN200720027706U CN201103349Y CN 201103349 Y CN201103349 Y CN 201103349Y CN U2007200277062 U CNU2007200277062 U CN U2007200277062U CN 200720027706 U CN200720027706 U CN 200720027706U CN 201103349 Y CN201103349 Y CN 201103349Y
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- box cupling
- oil casing
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- sealing
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Abstract
The utility model discloses a nipple for an oil casing, the main technical points of which are that an outer sealing surface of a pipe body comprises a convex crown face that smoothly transits with the end surface; an inner sealing surface of the joint hoop comprises a concave crown face that smoothly transits with the shoulder zone; the convex crown face and the concave crown face form a first main sealing structure of a interference; the outer sealing surface of the pipe body also comprises an outer cylindrical surface guided by an outer conical surface; the inner sealing surface of the joint hoop also comprises an inner cylindrical surface guided by an inner convex crown face; the outer conical surface and the outer cylindrical surface of the pipe body as well as the inner convex crown face and the inner cylindrical surface of the joint hoop form a second main sealing structure of the interference which is similar to a quadrangle. The nipple for the oil casing not only has the advantages of good sealing effect and high over-torsion-resistance capability, but also is easy to process and inspect as well as convenient to construct and operate; therefore, the nipple for the oil casing is suitable for being used in deep wells, high pressure gas wells and sites with relatively simple and crude construction conditions.
Description
Technical field
The utility model relates to the tubing and casing technical field, relates in particular to a kind of oil casing threaded joint.
Background technology
Development along with petroleum industry, the exploitation of deep-well, ultradeep well, gassiness oil well, horizontal well is more and more, the continuous deterioration of oil recovery hole condition and development of world economy are to the dependence and the demand of petroleum gas, traditional API helicitic texture pattern, its screw strength and sealing performance can not satisfy the requirement of aspects such as oil exploitation technology, safety.
Oil casing threaded round thread and the two kinds of structural shapes of trapezoidal thread of mainly containing of tradition API, its sealing are to be determined by the tightness degree that internal and external threads meshes.Because form of thread structure Design and process inevitable source of error, there is certain clearance between thread engagement, round thread mainly is to have the selenodont helical duct between at the bottom of internal and external threads crest and the tooth, and trapezoidal thread mainly is to have seam type gap helical duct between spigot surface.Because the existence of leakage path, in essence, its helicitic texture does not possess sealability, the screw thread that its sealing performance mainly relies on button to cause is out of shape, uses the thread surface coated metal, uses solid matter (as: copper, zinc, graphite etc.) blind, helical duct in the thread sealing grease to obtain, so this sealing is subjected to the influence that shakes in make-up torque, filler quality, variations in temperature even the following well operations and changes, so sealing effectiveness is unreliable, undesirable, can't normally use in the high environment of double thread sealing requirements.
For this reason, different screw threads and hermetically-sealed construction pattern have been studied by each tubing and casing factory, generally, the hermetically-sealed construction pattern has: the internal taper seat sealing of the internal conical surface seal of male cone (strobilus masculinus), outer convex arc surface, the cylinder sealing to foreign round of interior convex arc surface, the face of cylinder to the sealing on the face of cylinder etc. as primary seal, at the counterface secondary sealing area, form sealing; In addition, by the variation at form of thread spigot surface angle and bearing surface angle, influence the major-minor sealing surface and be subjected to opposing leakage ability under the external force effects such as interior external pressure, stretching, bending.But by analyzing, there are problems such as processing, measurement, sealing reliability in the different sealing structural shape:
1) subject matter of the internal conical surface seal of male cone (strobilus masculinus), the internal taper seat sealing of outer convex arc surface is the dimension survey difficulty of internal conical surface sealing place, needs the accurate special measurement instrument of configuration to measure by indirect method, is not easy to the check and the evaluation at scene, oil field.Owing to be that the inclined-plane seals the inclined-plane, this structure requires height for the cleaning at contact surface place, and contact surface exists the high foreign matter of any hardness may cause the scuffing of sealing surface and causes the discontinuous and band initial failure of band.
2) interior convex arc surface to foreign round the major defect of cylinder seal style be convex arc surface processing difficulties as primary sealing area, sealed diameter is measured inconvenient, especially this structure is very responsive to material generation yield deformation, and the value that yield deformation takes place is exactly the value that reduces of sealed increscence amount.
3) face of cylinder, is formed the sealing surface of interfering and is easy to generate adherent phenomenon during as primary seal the face of cylinder in last button process.
4) when shoulder during as sealing surface, when being subjected to axial tension load, axial strain is die-offed seal contact pressure and sealing performance is descended.
Summary of the invention
Technical problem to be solved in the utility model is: the utility model provides a kind of oil casing threaded joint, and it is good sealing effect not only, and is easy to process, is easy to check, construction operation convenience.
For solving the problems of the technologies described above, the technical solution of the utility model is: oil casing threaded joint, comprise body and box cupling, and described body has external screw thread, external seal face and end face, and described box cupling has internal thread, inner sealing surface and circular bead surface; The external seal face of described body is between described external screw thread and end face, and the inner sealing surface of described box cupling is between described internal thread and circular bead surface; Described external screw thread and described internal thread interconnect, the external seal face of described body and the inner sealing surface interference fit of described box cupling, the circular bead surface axial abutment of the end face of described body and described box cupling, the external seal face of described body comprises and the suitable convex arc surface of crossing that slips over of described end face, the inner sealing surface of described box cupling comprises and the suitable concaved circular cambered surface that crosses that slips over of described circular bead surface that described convex arc surface and described concaved circular cambered surface form the first primary seal structure of interference.
As a kind of optimal way, the external seal face of described body comprises the external cylindrical surface by the outer conical surface guiding, and described outer conical surface and described convex arc surface are crossed along slipping over; The inner sealing surface of described box cupling comprises that described inner cylinder face and concaved circular cambered surface cross along slipping over by the inner cylinder face of interior convex arc surface guiding; The interior convex arc surface of the outer conical surface of described body and external cylindrical surface and described box cupling and inner cylinder face form the second primary seal structure of approximate tetragonal interference.
As a kind of optimal way, the end face of described body and the circular bead surface of described box cupling are axially fitted, and form the secondary hermetically-sealed construction of contact.
As a kind of optimal way, because described external screw thread and described internal thread are mutual adaptive taper threads, the cone angle of the outer conical surface of described body is greater than the cone angle of described taper thread.
As a kind of optimal way, the end face of described body has identical inclination angle with the circular bead surface of described box cupling.
As a kind of optimal way, described external screw thread and described internal thread are trapezoidal threads.
After having adopted technique scheme, the beneficial effects of the utility model are: because the external seal face of described body comprises and the suitable convex arc surface of crossing that slips over of described end face, the inner sealing surface of described box cupling comprises and the suitable concaved circular cambered surface that crosses that slips over of described circular bead surface, after the assembling, described convex arc surface and described concaved circular cambered surface form the first primary seal structure of interference, like this, the process that convex arc surface produces contact and elastic deformation to concaved circular cambered surface is the process from the line to the face, therefore the high rigidity foreign matter that may exist sealing place at first has the effect of " pushing open ", therefore is difficult for causing the damage to band; Simultaneously, when body was subjected to bending, its sealing surface stress was constant substantially to the contact of circular arc for circular arc, and in the time of can avoiding the conical surface to the conical surface, lateral stress increases in bending direction, and lateral stress reduces and the situation that causes leaking takes place outside.
Because the external seal face of described body comprises the external cylindrical surface by the outer conical surface guiding, described outer conical surface and described convex arc surface are crossed along slipping over; The inner sealing surface of described box cupling comprises that described inner cylinder face and concaved circular cambered surface cross along slipping over by the inner cylinder face of interior convex arc surface guiding; After the assembling, the interior convex arc surface of the outer conical surface of described body and external cylindrical surface and described box cupling and inner cylinder face form the second primary seal structure of approximate tetragonal interference, so, when body is subjected to stretching, compression, can guarantee that the radial interference amount is always the magnitude of interference of design, thereby solved the conical surface conical surface, the conical surface are being subjected under the situation of tensile load during to ball face sealing, its sealed increscence amount reduces, and the problem that causes sealing effectiveness to reduce.And external cylindrical surface is guided by outer conical surface, inner cylinder face is guided by interior convex arc surface, therefore the magnitude of interference of the second primary seal structure can be chosen in the regime of elastic deformation of material, can not produce adherent phenomenon when button or shackle on repeated multiple times, guarantees the reliability and stability of sealing.
Because described external screw thread is that taper thread is connected with described internal thread, the cone angle of the outer conical surface of described body is greater than the cone angle of described taper thread, so it can prevent the sealing surface of damaging in the make-up process, forms the protection to sealing surface.
Because after the assembling, the end face of described body and the circular bead surface of described box cupling are axially fitted, form the secondary hermetically-sealed construction of contact, thereby strengthened the sealing effectiveness of nipple and resisted torque capability.
The utility model can provide three grades of sealings, and good sealing effect resisted torque capability strong.On body and box cupling in the button process, to the thread compound of smearing before the last button " preceding pushing away ", both guaranteed between sealing surface, to form lubricating layer, avoid thread compound to be formed " high pressure " in localized voids again and cause body, the too high adverse effect of bringing of box cupling local stress by shutoff, and execute-in-place is not needed to formulate strict thread compound smear rules, make things convenient for execute-in-place.Box cupling adopts inner cylinder face and concaved circular cambered surface hermetically-sealed construction, body adopts convex arc surface, outer conical surface and external cylindrical surface hermetically-sealed construction, does not adopt special cambered surface, spherical structure, so machining prgraming is not easily, need use dedicated tool, and percent defective is low, also is convenient to the oil field on-site maintenance; Check is convenient, as long as adopt conventional micron micrometer, apparatus for measuring radius of circular arc and bevel protractor, the projecting apparatus that adding manufacturer provides can be finished screw thread and detect.Being widely used in the simple and crude relatively place of deep-well, high-pressure gas well and execution conditions uses.
Description of drawings
Below in conjunction with drawings and Examples the utility model is further specified.
Fig. 1 is the longitudinal sectional view of the utility model embodiment;
Fig. 2 is the broken section enlarged drawing of middle box cupling embodiment illustrated in fig. 1;
Fig. 3 is the broken section enlarged drawing of middle tube body embodiment illustrated in fig. 1;
Fig. 4 is the broken section enlarged drawing after middle tube body embodiment illustrated in fig. 1 and the box cupling assembling.
The specific embodiment
A kind of oil casing threaded joint, shown in Fig. 1, Fig. 2 and Fig. 3 were common, it comprised body 1 and box cupling 2, and described body 1 has external screw thread, external seal face and end face 14, and described box cupling 2 has internal thread, inner sealing surface and circular bead surface 24; The external seal face of described body 1 is between described external screw thread and end face 14, and the inner sealing surface of described box cupling 2 is between described internal thread and circular bead surface 24.
Described external screw thread and described internal thread interconnect, and form of thread preferentially adopts trapezoidal thread.The spigot surface of this trapezoidal thread (be screw thread twist connect before internal and external threads tooth side in opposite directions) angle is 10 °～45 °, the bearing surface angle (be screw thread twist connect before the opposing tooth side of internal and external threads) be 3 °～-5 °, when the external diameter of the body 1 that is used to connect was big, the tooth of its screw thread was high and pitch is big accordingly; When the external diameter of the body 1 that is used to connect hour, the tooth of its screw thread is high and pitch is accordingly little, this is that those of ordinary skill is known, when this structure was used for oil pipe (external diameter is below the 4-1/2in), its height of thread was 0.9～1.2mm; Pitch is 3.175mm or 4.233mm; When being used for sleeve pipe (external diameter is more than the 4-1/2in), its height of thread is 1.575mm; Pitch is 5.08mm.Adopt at the bottom of the crest of present embodiment and the tooth and axis tapering pattern, i.e. taper thread structure, certainly, it also can adopt the form that parallels to the axis.
Shown in Fig. 2 and Fig. 3 are common, the external seal face of described body 1 comprises and the described end face 14 suitable convex arc surface 13 of crossing that slip over, the inner sealing surface of described box cupling 2 comprises and the described circular bead surface 24 suitable concaved circular cambered surfaces 23 that cross that slip over, after the assembling, as shown in Figure 4, described convex arc surface 13 and described concaved circular cambered surface 23 form the first primary seal structure a of interference.The magnitude of interference of the first primary seal structure a can change by adjusting radius size, its magnitude of interference is mainly considered to bear pressure and definite interference contact pressure value is determined the magnitude of interference that it is best to every kind of steel by finite element analysis by material SMYS value, body are required.Its effect is that the process that 13 pairs of concaved circular cambered surfaces of convex arc surface 23 produce contact and elastic deformation is the process from the line to the face, so the high rigidity foreign matter that sealing place may exist is at first had the effect of " pushing open ", so is difficult for causing the damage to band; Simultaneously, when body was subjected to bending, its sealing surface stress was constant substantially to the contact of circular arc for circular arc, and in the time of can avoiding the conical surface to the conical surface, lateral stress increases in bending direction, and lateral stress reduces and the situation that causes leaking takes place outside.
As shown in Figure 3, the external seal face of described body 1 comprises the external cylindrical surface 11 by outer conical surface 12 guiding, and described outer conical surface 12 is crossed along slipping over described convex arc surface 13.Determine the factor of external cylindrical surface 11 diameters, necessary effective external thread length in the time of should considering to guarantee bonding strength, and add and man-hour do not occur interference.The cone angle of outer conical surface 12 and length are mainly considered the guiding of sealing surface and are formed the length of sealing surface; the cone angle of the outer conical surface 12 of described body is during greater than the cone angle of described taper thread; it can prevent the sealing surface of damaging in the make-up process, thereby forms the protection to sealing surface.
As shown in Figure 2, the inner sealing surface of described box cupling 2 comprises the inner cylinder face 22 by interior convex arc surface 21 guiding, and described inner cylinder face 22 crosses along slipping over concaved circular cambered surface 23.Inner cylinder face 22 diameter values are mainly considered the size of the magnitude of interference, the guiding of determining main consideration sealing surface of interior convex arc surface 21 and the length of formation sealing surface.
After the assembling, as shown in Figure 4, the outer conical surface 12 of described body and external cylindrical surface 11 form the second primary seal structure b that is similar to tetragonal interference with the interior convex arc surface 21 and the inner cylinder face 22 of described box cupling.The magnitude of interference numerical value of sealing structure is determined by finite element analysis.Its effect is, be subjected to stretching at body 1, during compression, can guarantee that the radial interference amount is always the magnitude of interference of design, the conical surface, the conical surface are being subjected under the situation of tensile load during to ball face sealing thereby solved the conical surface, its sealed increscence amount reduces, and the problem that causes sealing effectiveness to reduce.And external cylindrical surface 11 is by outer conical surface 12 guiding, inner cylinder face 22 is by interior convex arc surface 21 guiding, therefore the magnitude of interference of the second primary seal structure b can be chosen in the regime of elastic deformation of material, can not produce adherent phenomenon when button or shackle on repeated multiple times, guarantees the reliability and stability of sealing.
It can also be seen that from Fig. 4 the end face 14 of described body is axially fitted with the circular bead surface 24 of described box cupling with circular bead surface 24 axial abutment of described box cupling, the end face 14 of described body, forms the secondary hermetically-sealed construction c of contact.The end face 14 of described body is a torque resistant with the main effect of the shoulder structure that the circular bead surface of described box cupling 24 forms, and only could fit in two plane under precision machined condition, forms the secondary hermetically-sealed construction c of contact.With respect to the plane perpendicular to axis, the end face 14 of described body and the circular bead surface 24 of described box cupling have identical inclination angle, and the scope at described inclination angle is 0～-15 °.Generally, the end face 14 of described body and the circular bead surface 24 axial abutment places of described box cupling, the diameter of bore size of the endoporus of box cupling 2 and body 1 is basic identical, thereby forms approximate interior flat structure pattern.She Ji benefit is to avoid vary in diameter to cause the body internal flow turbulent flow to occur and cause the washing away of body or box cupling inner surface avoided the local initial failure of body like this.
The utility model can provide three grades of sealings, and good sealing effect resisted torque capability strong.On body and box cupling in the button process, to the thread compound of smearing before the last button " preceding pushing away ", both guaranteed between sealing surface, to form lubricating layer, avoid thread compound to be formed " high pressure " in localized voids again and cause body, the too high adverse effect of bringing of box cupling local stress by shutoff, and execute-in-place is not needed to formulate strict thread compound smear rules, make things convenient for execute-in-place.Box cupling adopts inner cylinder face and concaved circular cambered surface hermetically-sealed construction, body adopts convex arc surface, outer conical surface and external cylindrical surface hermetically-sealed construction, does not adopt special cambered surface, spherical structure, so machining prgraming is not easily, need use dedicated tool, and percent defective is low, also is convenient to the oil field on-site maintenance; Check is convenient, as long as adopt conventional micron micrometer, apparatus for measuring radius of circular arc and bevel protractor, the projecting apparatus that adding manufacturer provides can be finished screw thread and detect.Being widely used in the simple and crude relatively place of deep-well, high-pressure gas well and execution conditions uses.
Claims (6)
1. oil casing threaded joint comprises
Body (1) and box cupling (2), described body (1) have external screw thread, external seal face and end face (14), and described box cupling (2) has internal thread, inner sealing surface and circular bead surface (24);
The external seal face of described body (1) is positioned between described external screw thread and the end face (14), and the inner sealing surface of described box cupling (2) is positioned between described internal thread and the circular bead surface (24);
Described external screw thread and described internal thread interconnect, the inner sealing surface interference fit of the external seal face of described body (1) and described box cupling (2), and circular bead surface (24) axial abutment of end face of described body (14) and described box cupling is characterized in that:
The external seal face of described body (1) comprise and described end face (14) along slipping over the convex arc surface (13) of crossing,
The inner sealing surface of described box cupling (2) comprise and described circular bead surface (24) along slipping over the concaved circular cambered surface (23) that crosses,
Described convex arc surface (13) and described concaved circular cambered surface (23) form the first primary seal structure (a) of interference.
2. oil casing threaded joint as claimed in claim 1 is characterized in that:
The external seal face of described body (1) comprises the external cylindrical surface (11) by outer conical surface (12) guiding, and described outer conical surface (12) is crossed along slipping over described convex arc surface (13);
The inner sealing surface of described box cupling (2) comprises the inner cylinder face (22) by interior convex arc surface (21) guiding, and described inner cylinder face (22) crosses along slipping over concaved circular cambered surface (23);
Outer conical surface of described body (12) and external cylindrical surface (11) form the second primary seal structure (b) that is similar to tetragonal interference with the interior convex arc surface (21) and the inner cylinder face (22) of described box cupling.
3. oil casing threaded joint as claimed in claim 2 is characterized in that: described external screw thread and described internal thread are mutual adaptive taper threads, and the cone angle of the outer conical surface of described body is greater than the cone angle of described taper thread.
4. as described any the oil casing threaded joint of claim 1 to 3, it is characterized in that: the end face of described body (14) is axially fitted with the circular bead surface (24) of described box cupling, forms the secondary hermetically-sealed construction (c) of contact.
5. oil casing threaded joint as claimed in claim 4 is characterized in that: the circular bead surface (24) of end face of described body (14) and described box cupling has identical inclination angle.
6. oil casing threaded joint as claimed in claim 3 is characterized in that: described external screw thread and described internal thread are trapezoidal threads.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2007200277062U CN201103349Y (en) | 2007-09-11 | 2007-09-11 | Screwed tie-in of oil casing tube |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2007200277062U CN201103349Y (en) | 2007-09-11 | 2007-09-11 | Screwed tie-in of oil casing tube |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201103349Y true CN201103349Y (en) | 2008-08-20 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2007200277062U Expired - Fee Related CN201103349Y (en) | 2007-09-11 | 2007-09-11 | Screwed tie-in of oil casing tube |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201103349Y (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101672166A (en) * | 2009-09-25 | 2010-03-17 | 江苏常宝普莱森钢管有限公司 | Tri-dimensional sealed tensile oil sleeve joint |
| CN102071881A (en) * | 2010-12-08 | 2011-05-25 | 中国石油集团石油管工程技术研究院 | Hermetic threaded joint of sleeve for gas well |
| CN102352727A (en) * | 2011-10-24 | 2012-02-15 | 大庆福斯特科技开发有限公司 | 8TPI oil or casing pipe threaded connector |
| CN104153716A (en) * | 2014-07-28 | 2014-11-19 | 聊城安泰石油机械有限公司 | Tubing and casing sealing coupling |
| CN105909183A (en) * | 2016-06-15 | 2016-08-31 | 东营威玛石油钻具有限公司 | Screwed joint of high-torsion-resistance drilling tool |
| CN108952595A (en) * | 2018-06-01 | 2018-12-07 | 江苏常宝钢管股份有限公司 | A kind of air-tight seal screw joint |
-
2007
- 2007-09-11 CN CNU2007200277062U patent/CN201103349Y/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101672166A (en) * | 2009-09-25 | 2010-03-17 | 江苏常宝普莱森钢管有限公司 | Tri-dimensional sealed tensile oil sleeve joint |
| CN102071881A (en) * | 2010-12-08 | 2011-05-25 | 中国石油集团石油管工程技术研究院 | Hermetic threaded joint of sleeve for gas well |
| CN102352727A (en) * | 2011-10-24 | 2012-02-15 | 大庆福斯特科技开发有限公司 | 8TPI oil or casing pipe threaded connector |
| CN104153716A (en) * | 2014-07-28 | 2014-11-19 | 聊城安泰石油机械有限公司 | Tubing and casing sealing coupling |
| CN105909183A (en) * | 2016-06-15 | 2016-08-31 | 东营威玛石油钻具有限公司 | Screwed joint of high-torsion-resistance drilling tool |
| CN108952595A (en) * | 2018-06-01 | 2018-12-07 | 江苏常宝钢管股份有限公司 | A kind of air-tight seal screw joint |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20080820 Termination date: 20160911 |
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| CF01 | Termination of patent right due to non-payment of annual fee |