CN202417340U - Threading connector for oil well pipe - Google Patents
Threading connector for oil well pipe Download PDFInfo
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- CN202417340U CN202417340U CN2011205766061U CN201120576606U CN202417340U CN 202417340 U CN202417340 U CN 202417340U CN 2011205766061 U CN2011205766061 U CN 2011205766061U CN 201120576606 U CN201120576606 U CN 201120576606U CN 202417340 U CN202417340 U CN 202417340U
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- oil well
- shoulder
- well pipe
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- 239000003129 oil well Substances 0.000 title claims abstract description 67
- 238000007789 sealing Methods 0.000 claims abstract description 121
- 230000008878 coupling Effects 0.000 claims description 60
- 238000010168 coupling process Methods 0.000 claims description 60
- 238000005859 coupling reaction Methods 0.000 claims description 60
- 230000002093 peripheral effect Effects 0.000 claims description 21
- 238000003780 insertion Methods 0.000 claims description 9
- 230000037431 insertion Effects 0.000 claims description 9
- 230000003746 surface roughness Effects 0.000 claims description 6
- 239000011324 bead Substances 0.000 abstract description 5
- 230000014509 gene expression Effects 0.000 description 18
- 238000010586 diagram Methods 0.000 description 17
- 238000003825 pressing Methods 0.000 description 6
- 230000006835 compression Effects 0.000 description 5
- 238000007906 compression Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 238000005461 lubrication Methods 0.000 description 5
- 238000005520 cutting process Methods 0.000 description 4
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- 208000014674 injury Diseases 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 210000002445 nipple Anatomy 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- VWVRASTUFJRTHW-UHFFFAOYSA-N 2-[3-(azetidin-3-yloxy)-4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]pyrazol-1-yl]-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethanone Chemical compound O=C(CN1C=C(C(OC2CNC2)=N1)C1=CN=C(NC2CC3=C(C2)C=CC=C3)N=C1)N1CCC2=C(C1)N=NN2 VWVRASTUFJRTHW-UHFFFAOYSA-N 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000007788 roughening Methods 0.000 description 1
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- Non-Disconnectible Joints And Screw-Threaded Joints (AREA)
- Earth Drilling (AREA)
Abstract
The utility model provides a threading connector for an oil well pipe. The threading connector for the oil well pipe (10-1) comprises: a male buckle (11) and a female buckle (21), wherein the male buckle is provided with an external thread part (12), a first sealing part (13), a first circular bead part (14) and a front-section unthreaded part (15); and the female buckle is provided with an internal thread part (22), a second sealing part (23) and a second circular bead part (24). The inclined angles of the first sealing part and the second sealing part (23) relative to an axis line are respectively 14 degrees-30 degrees; the front-section unthreaded part and the first sealing part are connected through an arc part with the radius being 3mm-11mm; a line of the second circular bead part (24), which is vertical to the axial line, has the inclined angle being 5 degrees-20 degrees; a front end part (16) of the male buckle is formed by an arc part with the radius being 0.6mm-0.9mm; and a part (25) of the female buckle (21), corresponding to the front end part (16) of the male buckle, is formed by an arc part with the radius being below 0.5mm.
Description
Technical field
The utility model relates to a kind of screw coupling for oil well pipe that employed oil well pipes such as the exploration of oil, natural gas, production are coupled together of being used for, and particularly relates to a kind of screw coupling for oil well pipe of metallic seal formula.
Background technology
As the screw coupling for oil well pipe that is used to connect oil well pipe, use round thread joint, the buttress thread joint of API specification usually.But, the crueltyization of the mining conditions that causes in view of deepening year by year along with the degree of depth of oil well, gas well, screw coupling for oil well pipe can bear 3 very big dimension load and be exposed under the harsh stress state.Particularly in producing well, be applied with circumferential stress in the pipe certainly, fully keep air-tightness under 3 axial stress for round thread joint, buttress thread joint and be not easy.
Therefore, by patent documentation 1 a kind of screw coupling for oil well pipe with metallic seal formula of metallic sealing section is disclosed.(a) of Fig. 6 is the integrally-built key diagram of this screw coupling for oil well pipe 0 of expression, and (b) of Fig. 6 is that the situation the when pin thread of screw coupling for oil well pipe 0 (ピ Application) 1 and box (ボ Star Network ス) 5 linked is amplified the partial sectional view of representing.In addition; (a) of Fig. 7 is the key diagram of binding situation midway of schematically representing pin thread 1 and the box 5 of screw coupling for oil well pipe 0; (b) of Fig. 7 schematically representes the pin thread 1 of screw coupling for oil well pipe 0 and the key diagram that box 5 links the situation when finishing; And (c) of Fig. 7 is the key diagram that leading portion is not had the connecting portion amplification expression of threaded portion and sealing.
Shown in Fig. 6 (a) and Fig. 6 (b), oil well pipe P, P utilize box cupling C (coupling) to be connected.Reference numeral 1 is the end among the box cupling C that is inserted into of oil well pipe P, expression pin thread portion, and Reference numeral 5 expressions are formed on the box portion among the box cupling C in order to receive pin thread 1.Screw coupling for oil well pipe 0 is the nipple that pin thread 1 and box 5 is screwed in the metallic seal formula that combines, and pin thread 1 has towards the front end external thread part 2 of the cone-shaped of undergauge gradually at its external surface.Be provided with towards the front end sealing 3 of the cone-shaped of undergauge gradually at the front end of external thread part 2.Be formed with on the top of pin thread 1 to the shoulder portion 4 of sharply tilting with external thread part 2 and sealing 3 opposite directions.On the other hand, box 5 surface within it has and external thread part 2 corresponding internal thread parts 6, is provided with in the inner end of internal thread part 6 and sealing 3 corresponding sealings 7, is provided with in inner end more and corresponding shoulder portion of shoulder portion 48.
Through in internal thread part 6, screwing in external thread part 2, sealing 3,7 contacts, and fetches pin thread 1 and box 5 sealings through 4,8 pairs in shoulder portion.In order to produce sufficient surface pressing at sealing surface, it is poor to pay the footpath that is known as amount of interference S between the sealing 7 to the sealing 3 of pin side and box side.Amount of interference S is defined as S=D
PX-D
BX(D
PX: the minimum diameter of pin side sealing, D
BX: the minimum diameter of box side sealing), S＞0, be D
PX＞D
BXThrough paying amount of interference S, screwing in midway, sealing 3,7 begins to interfere (with reference to (a) of Fig. 7), and shoulder portion 4,8 connects and combines to finish.The axial stroke that sealing 3,7 is begun to interfere with till combining to finish is called the amount of tightening up MOS.
In the sealed screw coupling for oil well pipe 0 of this metal covering; Because the footpath of sealing 3,7 is poor; Sealing 3,7 begin to interfere with till combining to finish during in, promptly screw in the amount of tightening up MOS during in, while sealing 3,7 is keeping higher surface pressing to slide with helical form.Therefore, sealing 3,7 be easy to bond (Japanese: baked is paid I).If bond, then the sealing surface roughening and produce locality the gap, produced the part of interference, sealing is impaired.
Therefore; A kind of such screw coupling for oil well pipe is disclosed in patent documentation 2; That is, in the sealed screw coupling for oil well pipe 0 of the face with metallic sealing section, the gradient of the sealing 3,7 of pin thread 1 and box 5 is made the taper more than 1/6; Make the gradient of its gradient, make the length L of the sealing 7 of box 5 greater than threaded portion 2,6
BLength L greater than the sealing 3 of pin thread 1
PBetween the external thread part 2 of pin thread 1 and sealing 3, form gradient and do not have threaded portion 9a less than the leading portion of the gradient of sealing 3; The curve 9b that utilization is tangential to sealing 3 does not have leading portion between threaded portion 9a and the sealing 3 and couples together, and makes in being present in this curve 9b and is 1.45mm more than to the distance at point of contact or from the border that leading portion does not have threaded portion 9a and a sealing 3 to any the less distance the distance at point of contact near the circular arc summit at the point of contact of curve 9b and sealing 3.
Schematic illustration; This screw coupling for oil well pipe does not have threaded portion 9a through between the external thread part 2 of pin thread 1 and sealing 3, forming gradient less than the leading portion of the gradient of sealing 3; Utilizing circular arc 9b leading portion not have between threaded portion 9a and the sealing 3 couples together; And to make the distance up to the intersection point of circular arc 9b and sealing 3 be more than the 1.45mm, prevents the bonding of sealing 3.
Patent documentation 1: japanese kokai publication hei 5-87275 communique
Patent documentation 2: japanese kokai publication hei 8-135855 communique
But, the problem of enumerating below in utilizing patent documentation 2 disclosed screw coupling for oil well pipe, existing (i), (ii).
(i) can be clear and definite by value in the table 2 of patent documentation 2 as example of the present invention specifically disclosed " sealing taper ", the taper of sealing 3,7 is less to be 1/6～1/2, converting is angled about 5 °～14 °.In addition, can be clear and definite by the value of " radius of curvature R of tangent line circular arc (mm) ", the leading portion of pin thread 1 does not have the R 12mm～32mm more greatly of the connecting portion of threaded portion 9a and sealing 3.In this structure, though can reduce contact stress, effective for anti-caking property, it is big that the shape of sealing can become.
(ii) no matter pin thread 1 is to interfere at sealing 3,7 places or interfere at shoulder portion 4,8 places with box 5, and it is open that the bonding of shoulder portion 4,8 prevents that method from all having no.
Summary of the invention
The utility model is as follows.
(1) a kind of screw coupling for oil well pipe; This screw coupling for oil well pipe comprises: pin thread, its have cone-shaped external thread part, be arranged on external thread part front end cone-shaped the 1st sealing, be arranged on the 1st shoulder portion on top and be arranged on external thread part and the 1st sealing between, the angle of slope do not have the threaded portion less than the leading portion at the angle of slope of the 1st sealing; Box, its have the cone-shaped that threadingly engages in external thread part internal thread part, be arranged on internal thread part the inner end and with the 1st sealing the 2nd sealing of the cone-shaped of interference on the radial direction and be arranged on inner end and with the 1st shoulder portion pin thread axially on the 2nd shoulder portion of interference; It is characterized in that; The angle of slope of the 1st sealing and the 2nd sealing is 14 °～30 ° with respect to vertically axis all; Leading portion does not have the threaded portion and utilizes radius to be connected for the arc sections of 3mm～11mm with the 1st sealing; The angle of inclination with respect to the line of axis normal of the 1st shoulder portion and the 2nd shoulder portion is 5 °～20 °; And the leading section of pin thread is that the arc sections of 0.6mm～0.9mm forms by radius, box formed by the arc sections below the radius 0.5mm with the corresponding part of leading section pin thread.
(2) according to (a 1) described screw coupling for oil well pipe; It is characterized in that external thread part and internal thread part are respectively that to insert tooth side angle (stabbing flankangle) be 5 °～35 ° and carry tooth side angle (load flank angle) exceeds 0.2mm～0.4mm for the height of the aspect ratio external thread part of-1 °～-5 ° and internal thread part trapezoidal thread.
According to (2) described screw coupling for oil well pipe, it is characterized in that (3) the insertion tooth side clearance when external thread part and internal thread part are combined is 30 μ m～150 μ m.
(4) according to each described screw coupling for oil well pipe in the item of (1) item～(3), it is characterized in that the surface roughness of the 1st sealing and the 2nd sealing sealing surface is separately counted 0.8 μ m～3.2 μ m with center line average roughness.
(5) according to each described screw coupling for oil well pipe in the item of (1) item～(4); It is characterized in that pin thread has the inner peripheral surface of the shape that satisfies following 3 conditions (A)～(C): (A) inner peripheral surface has the internal diameter identical in fact with the inner peripheral surface of box at the connecting portion place with the 1st shoulder portion; (B) along from the connecting portion of inner peripheral surface and the 1st shoulder portion axis direction towards the rear end side of pin thread, the parallel portion that internal diameter is constant forms more than the 2mm from connecting portion; (C) then parallel portion ground is formed with rake along the axis direction towards the rear end side of pin thread, this rake with the axis direction angulation be the angle inclination below ± 6 °.
(6) according to each described screw coupling for oil well pipe in the item of (1) item～(5); It is characterized in that; External diameter of pipe less than 5 inches situation under; The 2nd shoulder portion and in same box cupling the interval between the shoulder portion of adjacent box, be that the wide SW of shoulder is more than the 25mm, be under the situation more than 5 inches at external diameter of pipe, the wide SW of this shoulder is more than the 50mm.
Adopt the utility model of technical scheme 1; A kind of such screw coupling for oil well pipe can be provided; That is, increase to 14 °～30 °, and be that the arc sections of 3mm～11mm forms sealing and leading portion does not have the threaded portion by radius through angle of slope with sealing; Through when guaranteeing to produce the unsettled minimum contact surface of sealing performance, reducing the distance of slide plane, can have small-sized and good anti-caking property and sealing concurrently.In addition, adopting the utility model of technical scheme 1, is 5 °～20 ° scope through the angle that makes circular bead surface; And the shape of the leading section of pin thread made the arc sections of radius 0.6mm～0.9mm; And, the shape with the corresponding part of leading section pin thread in the box is made the arc sections below the radius 0.5mm, the lifting effect that can utilize sealing when linking is (because circular bead surface has inclination; After contacting with box sealing surface butt separately, pin thread on the radial direction of pin thread and box sealing surface separately, produces dividing potential drop; Therefore, the surface pressing of pin thread and box sealing surface separately rises, the sealing performance that can play stably) sealing performance of playing stably; And, can prevent to concentrate the bonding that causes by stress to the connecting portion of shoulder portion and sealing.
Adopt the utility model of technical scheme 2, can be when suppressing make-up (stabbing) keep the compression performance in the insertion tooth side contacts of screw thread in the degree of injury of the insertion tooth side of screw thread.In addition, adopt the utility model of technical scheme 2, keep cutting ability when can when suppressing cutting, in bearing surface, produce cut channel etc.And, the utility model of employing technical scheme 2, the external diameter that does not increase box just can promptly be emitted the lubrication pressure that produces in the binding.
Adopt the utility model of technical scheme 3, through in shoulder portion since compression and after the plastic strain insertion tooth side of screw thread contact with each other, play the effect of supporting compressive force, fully satisfy sealing performance.
Adopt the utility model of technical scheme 4, welding can not take place in the sliding phase when joint links, can keep the sealing performance of expectation.
Adopt the utility model of technical scheme 5, can under the fastening state of pin thread and box, also can not hinder the fluid of oil etc. mobile.
And, adopt the utility model of technical scheme 6, can not receive the influence of adjacent connector portions and obtain stable binding performance.
Description of drawings
Fig. 1 is the key diagram of pin thread and the box of an example of schematically representing the screw coupling for oil well pipe of the utility model situation when linking.
Fig. 2 is with the pin thread of this screw coupling for oil well pipe and the local key diagram that amplifies the ground expression of box.
Fig. 3 is the key diagram of pin thread and the box of another example of schematically representing the screw coupling for oil well pipe of the utility model situation when linking.
Fig. 4 is with the pin thread of this screw coupling for oil well pipe and the local key diagram that amplifies the ground expression of box.
Fig. 5 is the key diagram of the shape of expression external thread part and internal thread part.
(a) of Fig. 6 is the integrally-built key diagram of representing screw coupling for oil well pipe in the past, and (b) of Fig. 6 is that the situation the when pin thread of screw coupling for oil well pipe and box are linked is amplified the partial sectional view of ground expression.
(a) of Fig. 7 schematically representes the pin thread of screw coupling for oil well pipe in the past and the key diagram that box links situation midway; (b) of Fig. 7 schematically representes the pin thread of screw coupling for oil well pipe and the key diagram that box links the situation when finishing; (c) of Fig. 7 is the enlarged drawing that leading portion does not have the connecting portion of threaded portion and sealing, and the ground expression is amplified by the A portion of the pin thread in Fig. 7 (b).
The specific embodiment
Screw coupling for oil well pipe with reference to description of drawings the utility model.
Fig. 1 is the key diagram of the pin thread 11 of a routine 10-1 of schematically representing the screw coupling for oil well pipe of the utility model situation when linking with box 21, and Fig. 2 is the pin thread 11 and the box 21 local key diagrams that amplify the ground expression with this screw coupling for oil well pipe 10-1.
On the other hand; Fig. 3 is the key diagram of the pin thread 11 of another example 10-2 of schematically representing the screw coupling for oil well pipe of the utility model situation when linking with box 21, and Fig. 4 is the pin thread 11 and the box 21 local key diagrams that amplify the ground expression with this screw coupling for oil well pipe 10-2.
In addition, the Reference numeral Slb among Fig. 2, Fig. 4 representes the seal length of box 21, and Reference numeral S ab representes the sealing angle of box 21; Reference numeral Bnr representes the leading section radius of box 21, and Reference numeral Bsa representes the shoulder angle of box 21, and Reference numeral Slp representes the seal length of pin thread 11; Reference numeral Sap representes the sealing angle of pin thread 11; Reference numeral Spr representes the sealing radius of pin thread 11, and Reference numeral Pnr representes the leading section radius of pin thread 11, and Reference numeral Pra representes the recess angle (Japanese: レ セ ス angle: recess angle) of pin thread 11; Reference numeral Psa representes the shoulder angle of pin thread 11; Reference numeral Stp representes that the leading portion of pin thread 11 does not have the threaded portion, and Reference numeral Ttp representes the thread taper face of pin thread 11.In addition, the Reference numeral Pil among Fig. 4 representes the length of the parallel portion (inner cylindrical) in the inner peripheral surface of pin thread 11.
Like Fig. 1, shown in Figure 2, screw coupling for oil well pipe 10-1 comprises pin thread 11 and box 21, and like Fig. 3, shown in Figure 4, screw coupling for oil well pipe 10-2 also comprises pin thread 11 and box 21.
(A) inner peripheral surface 11a has the corresponding identical in fact internal diameter of position 21b with the inner peripheral surface 21a of box 21 with the connecting portion 11b place of the 1st shoulder portion 14.
(B) along from the connecting portion 11b of inner peripheral surface 11a and the 1st shoulder portion 14 towards the axis direction of the rear end side of pin thread 11 (left Fig. 2, Fig. 4 to), the parallel portion 11c that internal diameter is constant forms more than the 2mm from connecting portion 11b.
(C) then parallel portion 11c ground along being formed with rake 11d towards the axis direction of the rear end side of pin thread 11 (left among Fig. 2, Fig. 4 to), this rake 11d with the axis direction angulation be the angle inclination below ± 6 °.Fig. 1, Fig. 2 are situation about being formed with the rake 11d that tilts for angle below+6 ° with the axis direction angulation, and Fig. 3, Fig. 4 are situation about being formed with the rake 11d that tilts for the angle below-6 ° with the axis direction angulation.
The screw coupling for oil well pipe 10-1 of the utility model, screw coupling for oil well pipe 10-2 comprise the pin thread 11 of the inner peripheral surface 11a with the shape that all satisfies 3 conditions (A)～(C); Therefore, can under the fastening state of pin thread and box, can not hinder the fluid of oil etc. to flow yet.
On the other hand, box 21 comprises internal thread part the 22, the 2nd sealing 23 and the 2nd shoulder portion 24.
In addition, among Fig. 1, Fig. 3 to be called shoulder apart from SW wide.The wide SW of shoulder be the 2nd shoulder portion and in same box cupling the interval between the shoulder portion of adjacent box; In the oil pipe of external diameter of pipe less than 2-3/8 (19/8) inch～4-1/2 (9/2) inch 5 inches, under the for example API specification; The wide SW of shoulder is preferably more than the 25mm; And, external diameter of pipe be more than 5 inches, under the for example API specification 5 inches～16 inches or the bigger sleeve pipes, the wide SW of shoulder is preferably more than the 50mm.Under the situation of nipple, normally as long as link to accomplish, the size of radial direction is change knifeedge just, but wide through guaranteeing above-mentioned shoulder, can not receive the influence of the change that the binding by adjacent connector portions causes and obtains stable binding performance.
The 1st sealing 13 and the 2nd sealing 23 be 14 °～30 ° all with respect to the angle of slope of axis with respect to vertically axis.In materials such as high alloy, this angle of slope is during less than 14 °, and the distance of the slide plane that the 1st sealing 13 and the 2nd sealing 23 slide is elongated, bonds easily.On the other hand, during greater than 30 °, though can not bond, the width that produces the part of surface pressing when stretching is below the 0.5mm at this angle of slope, and sealing performance is unstable.
Leading portion does not have threaded portion 15 and utilizes the arc sections of radius 3mm～11mm to be connected with the 1st sealing 13.Its reason is that when the arc sections of utilizing radius less than 3mm connected, surface pressing is local to raise, and sealing bonds easily.On the other hand, when the arc sections of utilizing radius greater than 11mm connected, though anti-caking property is no problem, it is big that the shape of sealing becomes.
The 1st shoulder portion 14 and the 2nd shoulder portion 24 with respect to being 5 °～20 ° with the angle of inclination of the line of axis normal (below be also referred to as " slave station fillet degree ").At slave station fillet degree during less than 5 °; Can not embody the surface pressing that is caused by the lifting effect to metallic seal when linking with pin thread 11 rises; During greater than 20 °, the stress of the corner part that the metallic seal of box 21 and the 2nd shoulder portion 24 are constituted is concentrated and raise, and is unsatisfactory at slave station fillet degree.
The leading section 16 of pin thread 11 is formed by the arc sections of radius 0.6mm～0.9mm, and leading section 16 corresponding parts 25 box 21 and pin thread 11 are formed by the arc sections below the radius 0.5mm.
The radius of the arc sections of the leading section 16 of pin thread 11 is greater than the radius of the arc sections of box 21 and leading section 16 corresponding parts 25 pin thread 11.Its reason is, interferes with each other and can not bond.In addition; Owing to make the height of shoulder high effective for compression performance, torque performance; Therefore; In existing screw coupling for oil well pipe, the radius of the arc sections of the radius of the arc sections of the leading section 16 of pin thread 11, box 21 and leading section 16 corresponding parts 25 pin thread 11 is minimum preferable.
Screw coupling for oil well pipe 10-1, screw coupling for oil well pipe 10-2 with above key element increase to 14 °～30 ° with the angle of slope of sealing 13,23; And; Form the connecting portion that sealing 13,23 and leading portion do not have threaded portion 15 by the arc sections of radius 3mm～11mm; Therefore, while, can have small-sized and good anti-caking property and sealing concurrently through guaranteeing to produce the distance that the unsettled minimum contact surface of sealing performance reduces slide plane.
In addition; It is 5 °～20 ° scope that this screw coupling for oil well pipe 10-1, screw coupling for oil well pipe 10-2 make slave station fillet degree; And the shape of the leading section 16 of pin thread 11 made the arc sections of radius 0.6mm～0.9mm, and, the shape with leading section 16 corresponding parts 25 pin thread 11 box 21 is made the arc sections below the radius 0.5mm; Therefore; Can utilize the sealing performance of when linking the lifting effect of sealing 13,23 being played stably, and, can prevent to concentrate the bonding that causes by stress to the connecting portion of shoulder portion 14,24 and sealing 13,23.
Fig. 5 is the key diagram of the shape of expression external thread part 12 and internal thread part 22.Reference numeral θ among Fig. 5
1Tooth side angle, Reference numeral θ are inserted in expression
2Tooth side angle, Reference numeral H are carried in expression
PThe height of expression external thread part 12, Reference numeral H
BThe height of expression internal thread part 22, reference number C
STooth side clearance, T are inserted in expression
TaThe expression thread taper.
Being defined on the market of the BTC of API used all the year round, and inserting the tooth side angle is to be the size of general knowledge about 10 °.When inserting the tooth side angle less than 5 °, the degree of injury of the insertion tooth side of screw thread is bigger during make-up (stabbing).On the other hand, when inserting the tooth side angle greater than 35 °, the compression performance under the insertion tooth side contacts of screw thread reduces.Therefore, in the utility model, insert tooth side angle θ
1Be preferably 5 °～35 °.
In addition, seeing that crooked stretchings etc. are negative angle if carry the tooth side angle; Then be difficult to slippage (jump out), but cutting ability is relatively poor, therefore; Carrying the tooth side angle and do not make greater than-5 ° bigger negative angle preferablely, but is under 0 ° the situation carrying the tooth side angle, produces cut channel etc. at bearing surface during cutting; Therefore, can not negative angle fully.Thereby, according to precision, carry the tooth side angle and be preferably more than-1 °.Therefore, carry tooth side angle θ
2Be preferably-1 °～-5 °.
And, in the height H of internal thread part 22
BHeight H with external thread part 12
PWhen identical, the lubrication pressure that in binding, produces raises, and can not deviate from from box face fully.Height H at internal thread part 22
BHeight H with external thread part 12
PDifference during less than 0.2mm, the release of the lubrication pressure during binding is slower, even when after linking certainly, entering into well through 24 hours, also residual lubrication pressure.And, in the height H of internal thread part 22
BHeight H than external thread part 12
PWhen exceeding 0.4mm, though the lubrication pressure when linking discharges the height H of internal thread part 22
BToo high, if correspondingly do not increase the external diameter of box 21, just can't obtain identical screw efficiency.Therefore, the height H of preferred internal thread part 22
BHeight H than external thread part 12
PExceed the trapezoidal thread of 0.2mm～0.4mm.
Insertion tooth side clearance C when external thread part 12 and internal thread part 22 are combined
SBe 30 μ m when following,, can cause torque to be risen or insert the bonding of tooth side because the relation of poisson's ratio inserts tooth side and contact with each other when linking.In addition, along with inserting tooth side clearance C
SBecome big, threaded portion 11,21 becomes and does not contact, in shoulder portion 14,24 since compression and after the plastic strain insertion tooth side of screw thread contact with each other, thereby play the effect of supporting compressive force.Insert tooth side clearance C
SLimiting value be about 150 μ m, inserting tooth side clearance C
SWhen becoming big greater than 150 μ m, very big plastic strain takes place in shoulder portion 14,24, can't satisfy sealing performance.Therefore, insert tooth side clearance C
SBe preferably 30 μ m～150 μ m.
The surface roughness of the 1st sealing 13 and the 2nd sealing 23 sealing surface separately is less, and then sealing performance is higher, but the sliding phase when joint links, and surface roughness can cause welding in center line average roughness during less than 0.8 μ m.In addition, when this surface roughness became big in center line average roughness greater than 3.2 μ m ground, it is big that the fluctuating on the length direction becomes, so the sealing performance variation.Therefore, the surface roughness of the 1st sealing 13 and the 2nd sealing 23 sealing surface separately is preferably 0.8 μ m～3.2 μ m in center line average roughness.
Description of reference numerals
0, by patent documentation 1 disclosed screw coupling for oil well pipe; 1, pin thread; 2, external thread part; 3, sealing; 4, shoulder portion; 5, box portion; 6, internal thread part; 7, sealing; 8, shoulder portion; 9a, leading portion do not have the threaded portion; 9b, be tangential to the curve of sealing; The screw coupling for oil well pipe of 10-1,10-2, the utility model; 11, pin thread; 11a, inner peripheral surface; 11b, connecting portion; 11c, parallel portion; 11d, rake; 12, external thread part; 13, the 1st sealing; 14, the 1st shoulder portion; 15, leading portion does not have the threaded portion; 16, leading section; 21, box; 21a, inner peripheral surface; The position of 21b, correspondence; 22, internal thread part; 23, the 2nd sealing; 24, the 2nd shoulder portion; 25, with the corresponding part of leading section of pin thread.
Claims (10)
1. screw coupling for oil well pipe, this screw coupling for oil well pipe comprises:
Pin thread, its have cone-shaped external thread part, be arranged on external thread part front end cone-shaped the 1st sealing, be arranged on the 1st shoulder portion on top and be arranged on external thread part and the 1st sealing between, the angle of slope do not have the threaded portion less than the leading portion at the angle of slope of above-mentioned the 1st sealing;
Box, its have the cone-shaped that threadingly engages in above-mentioned external thread part internal thread part, be arranged on this internal thread part the inner end and with above-mentioned the 1st sealing the 2nd sealing of the cone-shaped of interference on the radial direction and be arranged on inner end and with above-mentioned the 1st shoulder portion above-mentioned pin thread axially on the 2nd shoulder portion of interference; It is characterized in that,
The angle of slope of above-mentioned the 1st sealing and the 2nd sealing is 14 °～30 ° with respect to the above-mentioned axial axis in edge all,
Above-mentioned leading portion does not have the threaded portion and utilizes radius to be connected for the arc sections of 3mm～11mm with the 1st sealing,
The angle of inclination with respect to the line of above-mentioned axis normal of above-mentioned the 1st shoulder portion and the 2nd shoulder portion is 5 °～20 °, and
The leading section of above-mentioned pin thread is that the arc sections of 0.6mm～0.9mm forms by radius, above-mentioned box is formed by the arc sections below the radius 0.5mm with the corresponding part of leading section this pin thread.
2. screw coupling for oil well pipe according to claim 1 is characterized in that,
Above-mentioned external thread part and above-mentioned internal thread part are respectively that to insert the tooth side angle be 5 °～35 ° and to carry the tooth side angle be the trapezoidal thread that the height of the above-mentioned external thread part of aspect ratio of-1 °～-5 ° and above-mentioned internal thread part exceeds 0.2mm～0.4mm.
3. screw coupling for oil well pipe according to claim 2 is characterized in that,
Insertion tooth side clearance when above-mentioned external thread part and internal thread part are combined is 30 μ m～150 μ m.
4. according to each described screw coupling for oil well pipe in the claim 1～3, it is characterized in that,
The surface roughness of above-mentioned the 1st sealing and above-mentioned the 2nd sealing sealing surface is separately counted 0.8 μ m～3.2 μ m with center line average roughness.
5. according to each described screw coupling for oil well pipe in the claim 1～3, it is characterized in that,
Above-mentioned pin thread has the inner peripheral surface of the shape that satisfies following 3 conditions (A)～(C):
(A) inner peripheral surface has the internal diameter identical in fact with the inner peripheral surface of above-mentioned box at the connecting portion place with above-mentioned the 1st shoulder portion;
(B) along from the connecting portion of inner peripheral surface and above-mentioned the 1st shoulder portion axis direction towards the rear end side of this pin thread, the parallel portion that internal diameter is constant forms more than the 2mm from above-mentioned connecting portion;
(C) follow above-mentioned parallel portion ground and be formed with rake along above-mentioned axis direction towards the rear end side of this pin thread, this rake with above-mentioned axis direction angulation be the angle inclination below ± 6 °.
6. screw coupling for oil well pipe according to claim 4 is characterized in that,
Above-mentioned pin thread has the inner peripheral surface of the shape that satisfies following 3 conditions (A)～(C):
(A) inner peripheral surface has the internal diameter identical in fact with the inner peripheral surface of above-mentioned box at the connecting portion place with above-mentioned the 1st shoulder portion;
(B) along from the connecting portion of inner peripheral surface and above-mentioned the 1st shoulder portion axis direction towards the rear end side of this pin thread, the parallel portion that internal diameter is constant forms more than the 2mm from above-mentioned connecting portion;
(C) follow above-mentioned parallel portion ground and be formed with rake along above-mentioned axis direction towards the rear end side of this pin thread, this rake with above-mentioned axis direction angulation be the angle inclination below ± 6 °.
7. according to each described screw coupling for oil well pipe in the claim 1～3, it is characterized in that,
External diameter of pipe less than 5 inches situation under, above-mentioned the 2nd shoulder portion and in same box cupling the interval between the shoulder portion of adjacent box, be shoulder wide be under the situation more than 5 inches for more than the 25mm at external diameter of pipe, this shoulder is wide to be more than the 50mm.
8. screw coupling for oil well pipe according to claim 4 is characterized in that,
External diameter of pipe less than 5 inches situation under, above-mentioned the 2nd shoulder portion and in same box cupling the interval between the shoulder portion of adjacent box, be shoulder wide be under the situation more than 5 inches for more than the 25mm at external diameter of pipe, this shoulder is wide to be more than the 50mm.
9. screw coupling for oil well pipe according to claim 5 is characterized in that,
External diameter of pipe less than 5 inches situation under, above-mentioned the 2nd shoulder portion and in same box cupling the interval between the shoulder portion of adjacent box, be shoulder wide be under the situation more than 5 inches for more than the 25mm at external diameter of pipe, this shoulder is wide to be more than the 50mm.
10. screw coupling for oil well pipe according to claim 6 is characterized in that,
External diameter of pipe less than 5 inches situation under, above-mentioned the 2nd shoulder portion and in same box cupling the interval between the shoulder portion of adjacent box, be shoulder wide be under the situation more than 5 inches for more than the 25mm at external diameter of pipe, this shoulder is wide to be more than the 50mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011205766061U CN202417340U (en) | 2011-12-29 | 2011-12-29 | Threading connector for oil well pipe |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011205766061U CN202417340U (en) | 2011-12-29 | 2011-12-29 | Threading connector for oil well pipe |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202417340U true CN202417340U (en) | 2012-09-05 |
Family
ID=46742113
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011205766061U Expired - Lifetime CN202417340U (en) | 2011-12-29 | 2011-12-29 | Threading connector for oil well pipe |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202417340U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103556956A (en) * | 2013-11-01 | 2014-02-05 | 南通永大管业股份有限公司 | Self-adaptive screw thread structure for high sealing performance oil pipe |
| CN105899864A (en) * | 2014-01-09 | 2016-08-24 | 新日铁住金株式会社 | Threaded joint for steel pipe |
| CN110720006A (en) * | 2017-05-12 | 2020-01-21 | 超优质服务有限责任公司 | Curve sealing system |
-
2011
- 2011-12-29 CN CN2011205766061U patent/CN202417340U/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103556956A (en) * | 2013-11-01 | 2014-02-05 | 南通永大管业股份有限公司 | Self-adaptive screw thread structure for high sealing performance oil pipe |
| CN103556956B (en) * | 2013-11-01 | 2015-11-25 | 南通永大管业股份有限公司 | A kind of self adaptation helicitic texture of high leakproofness oil pipe |
| CN105899864A (en) * | 2014-01-09 | 2016-08-24 | 新日铁住金株式会社 | Threaded joint for steel pipe |
| CN110720006A (en) * | 2017-05-12 | 2020-01-21 | 超优质服务有限责任公司 | Curve sealing system |
| CN110720006B (en) * | 2017-05-12 | 2021-12-03 | 超优质服务有限责任公司 | Curve sealing system |
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Owner name: NIPPON STEEL + SUMITOMO METAL CORPORATION Free format text: FORMER OWNER: CHUGAI SEIYAKU KABUSHIKI KAISHA Effective date: 20130506 |
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Owner name: VALLOUREC PETROLEUM AND GAS SAS Effective date: 20131210 |
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Effective date of registration: 20131210 Address after: Tokyo, Japan, Japan Patentee after: Nippon Steel Corporation Patentee after: VALLOUREC MANNESMANN OIL & GAS FRANCE Address before: Tokyo, Japan, Japan Patentee before: Nippon Steel Corporation |
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| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: Tokyo, Japan, Japan Co-patentee after: VALLOUREC MANNESMANN OIL & GAS FRANCE Patentee after: Nippon Iron & Steel Corporation Address before: Tokyo, Japan, Japan Co-patentee before: VALLOUREC MANNESMANN OIL & GAS FRANCE Patentee before: Nippon Steel Corporation |
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Granted publication date: 20120905 |