CN103362450A - Non-coupling multi-sealing tooth-width-variable wedge type threaded oil well pipe structure - Google Patents

Abstract

The invention discloses a non-coupling multi-sealing tooth-width-variable wedge type threaded oil well pipe structure which comprises a pipe body outer thread section, a pipe body inner thread section, an oil well pipe body, an inner thread left sealing section, an outer thread right sealing section, an inner thread right sealing section and an outer thread left sealing section. The pipe body outer thread section is connected to the right end of the oil well pipe body, the outer thread left sealing section is arranged between the pipe body outer thread section and the oil well pipe body, the outer thread right sealing section is arranged on the right end portion of the pipe body outer thread section, the pipe body inner thread section is connected to the left end of the oil well pipe body, the inner thread right sealing section is arranged between the pipe body inner thread section and the oil well pipe body, and the inner thread left sealing section is arranged on the left end portion of the pipe body inner thread section. By means of the non-coupling multi-sealing tooth-width-variable wedge type threaded oil well pipe structure, the connection sealing performance, the bending resistance, the compression load resistance and the torque resistance of screwed joints are improved notably and effectively.

Description

A kind of without the wide wedge type thread compound of the multi-sealed change tooth of box cupling well casing structure

Technical field

The invention discloses the oil well pipe structure that a kind of oil drilling industry is used, the present invention is specially a kind of without the wide wedge type thread compound of the multi-sealed change tooth of box cupling well casing structure.

Background technology

At present, oil casing threaded connection structure form in the oil well pipe industry substantially all is to carry out improvement and bring new ideas according to API SPEC 5B " processing of sleeve pipe, oil pipe and line pipe thread, measurement and inspection specification " standard, the quality that is threaded of overall quality of connection comparison API standard-required progressively improves a lot, but or can not satisfy the oilfield exploitation instructions for use.Each oil field, the world that causes gradually all connects higher, the more preferably requirement of proposition at double thread, particularly requires more and more stricter to the relevant main performance index of oil well pipe.

Summary of the invention

The objective of the invention is to overcome the deficiencies in the prior art, provide a kind of can effectively increase high sealing performance, counter-bending ability, incompressible load-carrying ability and high resistance torsional performance that nipple connects without the wide wedge type thread compound of the multi-sealed change tooth of box cupling well casing structure.

According to technical scheme provided by the invention, described a kind of without the wide wedge type thread compound of the multi-sealed change tooth of box cupling well casing structure, comprise body external thread section, body internal thread segment, oil well pipe body, the left seal section of internal thread and the right seal section of external screw thread, the right seal section of internal thread and the left seal section of external screw thread; The body external thread section is the right-hand member that is connected to the oil well pipe body, between body external thread section and oil well pipe body, be provided with the left seal section of external screw thread, be provided with the right seal section of external screw thread in the right part of body external thread section, the body internal thread segment is the left end that is connected to the oil well pipe body, between body internal thread segment and oil well pipe body, be provided with the right seal section of internal thread, be provided with the left seal section of internal thread in the left part of body internal thread segment.

On the described body external thread section direction from right to left, the facewidth of described body external thread section is gradually, and increase arranges, the space width of body external thread section is dwindles setting gradually, the difference of adjacent two facewidth equates with the difference of adjacent two space widths, the height of each tooth of body external thread section equates that the tapering of body external thread section is 1:16 ~ 1:24; On the longitudinal cross-section of oil well pipe, each tooth on the body external thread section is wedge shape, is equipped with barb in the both sides, top of each tooth; The middle top of each tooth on the body external thread section is outer crest top land, the left side of outer crest top land is provided with the left plane of outer tooth top, the right side of outer crest top land is provided with the right plane of outer tooth top, link to each other by the left transition arc of outer crest top land between the left plane of outer tooth top and the outer crest top land, link to each other by the right transition arc of outer crest top land between the right plane of outer tooth top and the outer crest top land, the teeth groove middle part is the external tooth bottom surface, the external tooth bottom surface is taper seat, outer crest top land is taper seat, and outer crest top land, the tapering of external tooth bottom surface equates with the tapering of body external thread section, the left side of external tooth bottom surface is provided with left plane at the bottom of the external tooth, the right side of external tooth bottom surface is provided with right plane at the bottom of the external tooth, the right side wall of each tooth is provided with outer spigot surface, the axis angulation of outer spigot surface and oil well pipe is 79 ~ 85 °, the left side wall of each tooth is provided with outer bearing surface, the axis angulation of outer bearing surface and oil well pipe is 76 ~ 82 °, the external tooth bottom surface with link to each other by the left transition arc in external tooth bottom surface between the left plane at the bottom of the external tooth, the external tooth bottom surface with link to each other by the right transition arc in external tooth bottom surface between the right plane at the bottom of the external tooth, link to each other by right circular arc at the bottom of the external tooth between right plane and the outer bearing surface at the bottom of the external tooth, link to each other by the left circular arc of outer tooth top between outer bearing surface and the left plane of outer tooth top, link to each other by left circular arc at the bottom of the external tooth between left plane and the outer spigot surface at the bottom of the external tooth, link to each other by the right circular arc of outer tooth top between outer spigot surface and the outer tooth top outerplanar, the axis angulation of left plane and oil well pipe is 10 ~ 20 ° at the bottom of the internal tooth, the axis angulation of the right plane of outer tooth top and oil well pipe is 10 ~ 20 °, the axis angulation of right plane and oil well pipe is 7 ~ 17 ° at the bottom of the external tooth, and the axis angulation of the left plane of outer tooth top and oil well pipe is 7 ~ 17 °.

The tapering of described body external thread section is 1:18 ~ 1:20; The number of threads of described body external thread section is 12 ~ 30; The first buckle teeth of body external thread section is wide to be 1.8 ~ 3.2mm; The spigot surface pitch of body external thread section is 3.96 ~ 9.60mm; The bearing surface pitch of body external thread section is: (it is wide that the external screw thread total length deducts 2 times of first buckle teeth)/(always detain number and deduct 1); The first buckle teeth groove width of body external thread section is: it is wide that spigot surface pitch deducts first buckle teeth; The tooth depth of body external thread section is 1.5 ~ 2.5mm.

On the longitudinal cross-section of oil well pipe, the first buckle teeth of body external thread section is wide to be 1.8 ~ 3.2mm; The tooth depth of each tooth of body external thread section is 1.5 ~ 2.5mm; The width on the left plane of outer tooth top is 0.5 ~ 3.0 mm; The width of outer bearing surface is 0.5 ~ 2.0 mm; The width on right plane is 0.5 ~ 3.0 mm at the bottom of the external tooth; The width on the right plane of outer tooth top is 0.5 ~ 3.0 mm; The width of outer spigot surface is 0.5 ~ 2.0 mm; The width on left plane is 0.5 ~ 3.0 mm at the bottom of the external tooth; The width of outer crest top land is 0.05 ~ 6.0 mm; The width of external tooth bottom surface is 0.05 ~ 6.0 mm; The radius of the right circular arc of outer tooth top is 0.20 ~ 0.50mm; The radius of left circular arc is 0.20 ~ 0.50mm at the bottom of the external tooth; The radius of the left circular arc of outer tooth top is 0.20 ~ 0.50mm; The radius of right circular arc is 0.20 ~ 0.50mm at the bottom of the external tooth; The radius of the right transition arc of outer crest top land is 0.15 ~ 0.30mm; The radius of the left transition arc of outer crest top land is 0.15 ~ 0.30mm; The radius of the left transition arc in external tooth bottom surface is 0.15 ~ 0.30mm; The radius of the right transition arc in external tooth bottom surface is 0.15 ~ 0.30mm; Angle between the axis of outer bearing surface and oil well pipe is 2 ~ 6 ° less than the angle between the axis of outer spigot surface and oil well pipe.

On the longitudinal cross-section of oil well pipe, the right seal section of described external screw thread comprises outside outside outer primary sealing area, the outside outside secondary sealing area, the outside outside the 3rd sealing surface, the outside circular bead surface and inboard wall of tube body transition face outside shoulder summit cambered surface, the outside; Be positioned at the bottom of the external tooth of the rightmost side that primary sealing area joins outside the left plane and outside, secondary sealing area joins outside the outer primary sealing area in outside and the outside, the 3rd sealing surface joins outside the outer secondary sealing area in outside and the outside, shoulder summit cambered surface rounding off outside outer the 3rd sealing surface in outside and the outside, circular bead surface rounding off outside outside outer shoulder summit cambered surface and the outside, the outer circular bead surface in outside and inboard wall of tube body transition face, the inner hole wall of inboard wall of tube body transition face and oil well pipe joins.

On the longitudinal cross-section of oil well pipe, the length of primary sealing area is 3.0 ~ 6.0mm outside the described outside, and the tapering of primary sealing area is greater than the tapering of body external thread section outside the outside; The length of the outer secondary sealing area in outside is 3.0 ~ 6.0mm, and secondary sealing area is taper seat, outer convex globoidal or inner concave arc surface outside the outside, and when secondary sealing area was cambered surface outside the outside, its corresponding central angle number of degrees were 12 ~ 18 °; The length of outer the 3rd sealing surface in outside is 4.0 ~ 8.0mm, and the 3rd sealing surface is taper seat, outer convex globoidal or inner concave arc surface outside the outside, and when the 3rd sealing surface was cambered surface outside the outside, its corresponding central angle number of degrees were 3 ~ 9 °; The radius of outer shoulder summit, outside cambered surface is: 0.2 ~ 0.5mm, and its corresponding central angle number of degrees are 50 ~ 65 °; The radius of the outer circular bead surface in outside is 4.0 ~ 20.0mm, and circular bead surface is taper seat, outer convex globoidal or inner concave arc surface outside the outside, and when circular bead surface was cambered surface outside the outside, its corresponding central angle number of degrees were 60 ~ 85 °; The length of inboard wall of tube body transition face is 5 ~ 20mm, and the axis angulation of inboard wall of tube body transition face and oil well pipe is 5 ~ 10 °; The line at outer secondary sealing area two ends, outside and the axis angulation of oil well pipe are 12 ~ 18 °; The line at outer the 3rd sealing surface two ends, outside and the axis angulation of oil well pipe are 3 ~ 9 °; The line at outer circular bead surface two ends, outside and the axis angulation of oil well pipe are 60 ~ 85 °.

On the longitudinal cross-section of oil well pipe, the left seal section of described external screw thread comprises in the outside in the primary sealing area, outside in secondary sealing area, the outside in the 3rd sealing surface, the outside circular bead surface in the shoulder summit cambered surface and outside; The right plane of outer tooth top and the outside primary sealing area that are positioned at the leftmost side join, secondary sealing area joins in the interior primary sealing area in outside and the outside, the 3rd sealing surface joins in the interior secondary sealing area in outside and the outside, shoulder summit cambered surface rounding off in the 3rd sealing surface and the outside in the outside, circular bead surface rounding off in shoulder summit cambered surface and the outside in the outside, the outer wall of circular bead surface and oil well pipe joins by fillet in the outside.

On the longitudinal cross-section of oil well pipe, the length of primary sealing area is 3.0 ~ 6.0mm in the described outside, and its tapering is greater than the tapering of body external thread section; The length of secondary sealing area is 3.0 ~ 6.0mm in the outside, and secondary sealing area is taper seat, outer convex globoidal or inner concave arc surface in the outside, and when secondary sealing area was cambered surface in the outside, its corresponding central angle number of degrees were 12 ~ 18 °; The length of the 3rd sealing surface is in the outside, 4.0 ~ 8.0mm, and the 3rd sealing surface is taper seat, outer convex globoidal or inner concave arc surface in the outside, when the 3rd sealing surface was cambered surface in the outside, its corresponding central angle number of degrees were 3 ~ 9 °; The radius of shoulder summit cambered surface is 0.2 ~ 0.5mm in the outside, and its corresponding central angle number of degrees are 50 ~ 65 °; Circular bead surface is taper seat, outer convex globoidal or inner concave arc surface in the outside, and when circular bead surface was cambered surface in the outside, its radius was 4.0 ~ 20.0mm, and its corresponding central angle number of degrees are 60 ~ 85 °; The line at secondary sealing area two ends and the axis angulation of oil well pipe are 12 ~ 18 ° in the outside; The line at the 3rd sealing surface two ends and the axis angulation of oil well pipe are 3 ~ 9 ° in the outside; The line at circular bead surface two ends and the axis angulation of oil well pipe are 60 ~ 85 ° in the outside.

On the described body internal thread segment direction from left to right, the facewidth of body internal thread segment is gradually, and increase arranges, the space width of body internal thread segment is dwindles setting gradually, the difference of adjacent two facewidth equates with the difference of adjacent two space widths, the height of each tooth of body internal thread segment equates that the tapering of body internal thread segment is 1:16 ~ 1:24; On the longitudinal cross-section of oil well pipe, each tooth on the body internal thread segment is wedge shape, is equipped with barb in the both sides, top of each tooth; The middle top of each tooth on the body internal thread segment is interior crest top land, the left side of interior crest top land is provided with the left plane of interior tooth top, the right side of interior crest top land is provided with the right plane of interior tooth top, link to each other by the left transition arc of interior crest top land between the left plane of interior tooth top and the interior crest top land, link to each other by the right transition arc of interior crest top land between the right plane of interior tooth top and the interior crest top land, the teeth groove middle part is the internal tooth bottom surface, the internal tooth bottom surface is taper seat, interior crest top land is taper seat, and internal tooth bottom surface, the tapering of interior crest top land equates with the tapering of body internal thread segment, the left side of internal tooth bottom surface is provided with left plane at the bottom of the internal tooth, the right side of internal tooth bottom surface is provided with right plane at the bottom of the internal tooth, the right side wall of each tooth is provided with interior spigot surface, the axis angulation of interior spigot surface and body internal thread segment is 79 ~ 85 °, the left side wall of each tooth is provided with interior bearing surface, the axis angulation of interior bearing surface and body internal thread segment is 76 ~ 82 °, link to each other by the left transition arc in internal tooth bottom surface between internal tooth bottom surface and the inner plane at the bottom of the internal tooth, link to each other by the right transition arc in internal tooth bottom surface between internal tooth bottom surface and the outerplanar at the bottom of the internal tooth, link to each other by right circular arc at the bottom of the internal tooth between right plane and the interior spigot surface at the bottom of the internal tooth, link to each other by the left circular arc of interior tooth top between interior spigot surface and the left plane of interior tooth top, link to each other by left circular arc at the bottom of the internal tooth between left plane and the interior bearing surface at the bottom of the internal tooth, link to each other by the right circular arc of interior tooth top between interior bearing surface and the right plane of interior tooth top, the axis angulation of left plane and oil well pipe is 10 ~ 20 ° at the bottom of the internal tooth, the axis angulation of the right plane of interior tooth top and oil well pipe is 10 ~ 20 °, the axis angulation of right plane and oil well pipe is 7 ~ 17 ° at the bottom of the internal tooth, and the axis angulation of the left plane of interior tooth top and oil well pipe is 7 ~ 17 °.

On the longitudinal cross-section of oil well pipe, the left seal section of described internal thread comprises the outer primary sealing area of inner face, the outer secondary sealing area of inner face, outer the 3rd sealing surface of inner face, the outer shoulder summit cambered surface of inner face and the outer circular bead surface of inner face; Be positioned at that right plane and the outer primary sealing area of inner face join at the bottom of the internal tooth of the leftmost side, the outer primary sealing area of inner face and the outer secondary sealing area of inner face join, the outer secondary sealing area of inner face and outer the 3rd sealing surface of inner face join, outer the 3rd sealing surface of inner face and the outer shoulder summit of inner face cambered surface rounding off, the outer shoulder summit cambered surface of inner face and the outer circular bead surface rounding off of inner face, the outer wall of the outer circular bead surface of inner face and oil well pipe joins.

On the longitudinal cross-section of oil well pipe, the length of the outer primary sealing area of described inner face is 3.0 ~ 6.0mm, and its tapering is greater than the tapering of body internal thread segment; The length of the outer secondary sealing area of inner face is 3.0 ~ 6.0mm, and the outer secondary sealing area of inner face is taper seat, outer convex globoidal or inner concave arc surface, and the outer secondary sealing area of inner face is when being cambered surface, and its corresponding central angle number of degrees are 12 ~ 18 °; The length of outer the 3rd sealing surface of inner face is 4.0 ~ 8.0mm, and outer the 3rd sealing surface of inner face is taper seat, outer convex globoidal or inner concave arc surface, and outer the 3rd sealing surface of inner face is when being cambered surface, and its corresponding central angle number of degrees are 3 ~ 9 °; The radius of the outer shoulder summit of inner face cambered surface is 0.2 ~ 0.5mm, and its corresponding central angle number of degrees are 50 ~ 65 °; The outer circular bead surface of inner face is taper seat, outer convex globoidal or inner concave arc surface, and the outer circular bead surface of inner face is when being cambered surface, and the radius of the outer circular bead surface of inner face is 4 ~ 20mm, and its corresponding central angle number of degrees are 60 ~ 85 °; The line at the outer secondary sealing area two ends of inner face and the axis angulation of oil well pipe are 10 ~ 20 °; The line at outer the 3rd sealing surface two ends of inner face and the axis angulation of oil well pipe are 5 ~ 15 °; The line at the outer circular bead surface two ends of inner face and the axis angulation of oil well pipe are 60 ~ 85 °.

On the longitudinal cross-section of oil well pipe, the right seal section of described internal thread comprises the 3rd sealing surface, the interior shoulder summit cambered surface of inner face and the interior circular bead surface of inner face in primary sealing area in the inner face, the interior secondary sealing area of inner face, the inner face; The left plane of tooth top and the inner face primary sealing area that are positioned at the rightmost side join, the interior secondary sealing area of primary sealing area and inner face joins in the inner face, interior the 3rd sealing surface of secondary sealing area and inner face joins in the inner face, shoulder summit cambered surface rounding off in the 3rd sealing surface and the inner face in the inner face, circular bead surface rounding off in shoulder summit cambered surface and the inner face in the inner face, the inner hole wall of circular bead surface and oil well pipe joins by fillet in the inner face.

On the longitudinal cross-section of oil well pipe, the length of primary sealing area is 3.0 ~ 6.0mm in the described inner face, and its tapering is greater than the tapering of body internal thread segment; The length of secondary sealing area is 3.0 ~ 6.0mm in the inner face, and secondary sealing area is taper seat, outer convex globoidal or inner concave arc surface in the inner face, and when secondary sealing area was cambered surface in the inner face, its corresponding central angle number of degrees were 12 ~ 18 °; The length of the 3rd sealing surface is 4.0 ~ 8.0mm in the inner face, and the 3rd sealing surface is taper seat, outer convex globoidal or inner concave arc surface in the inner face, and when the 3rd sealing surface was cambered surface in the inner face, its corresponding central angle number of degrees were 3 ~ 9 °; The radius of shoulder summit cambered surface is 0.2 ~ 0.5mm in the inner face, and its corresponding central angle number of degrees are 50 ~ 65 °; Circular bead surface is taper seat, outer convex globoidal or inner concave arc surface in the inner face, and when circular bead surface was cambered surface in the inner face, its radius was 4 ~ 20mm, and its corresponding central angle number of degrees are 60 ~ 85 °; The line at secondary sealing area two ends and the axis angulation of oil well pipe are 10 ~ 20 ° in the inner face; The line at the 3rd sealing surface two ends and the axis angulation of oil well pipe are 5 ~ 15 ° in the inner face; The line at circular bead surface two ends and the axis angulation of oil well pipe are 60 ~ 85 ° in the inner face.

The number of threads of described body internal thread segment is 12 ~ 30; The first buckle teeth well width of body internal thread segment is 1.8 ~ 3.2mm; The spigot surface pitch of body internal thread segment is 3.96 ~ 9.60; The bearing surface pitch of body internal thread segment equals: (the internal thread total length deducts 2 times of first buckle teeth groove widths)/(always detain number and deduct 1); The first buckle teeth of body internal thread segment is wide to be: spigot surface pitch deducts first buckle teeth groove width; The tooth depth of body internal thread segment is: 1.5 ~ 2.5mm.

The present invention has the following advantages:

1. the shape that screw thread is screwed thread form is improved, the two barb tooth side angle shapes of wedge shape have been adopted, the tooth side angle on both sides adopts the bearing surface angle greater than the spigot surface angle, play screw thread both sides tooth side is contacted fully with the tooth side, and its each profile of tooth tooth side is evenly distributed its sealing performance of Effective Raise and bonding strength under the interference fit stress.

2. be improved to the thread form bearing surface of the form of thread and the pitch of thread form spigot surface unequal, and spigot surface pitch is greater than bearing surface pitch, its tooth width is to increase gradually, the alveolus width is to reduce gradually to occur becoming the wide helicitic texture form of tooth, its both tooth side lead angle angle is different simultaneously, shape is at a certain angle, two tooth sides consist of the wedge shape conical surface, the profile of tooth of internal and external threads cooperates the wedge thread fit structure that has just formed the wedge shape conical surface and the wedge shape conical surface, have differently significantly from two parallel tooth sides of API buttress thread, can significantly improve the bonding strength after its internal and external threads joint cooperates, sealing performance and bending resistance and mistake torsional performance.

3. be improved to the thread form bearing surface of the form of thread and the pitch of thread form spigot surface unequal, and spigot surface pitch is greater than the wide helicitic texture form of the change tooth of bearing surface pitch, profile of tooth width when internal and external screw thread begins to screw near end face is all less than space width, the very simple and convenient thread alternating phenomenon of having stopped of make-up, Effective Raise product quality and operating efficiency.

4. owing to adopted the change tooth wide thread forms of spigot surface pitch greater than bearing surface pitch, effectively reduce the various impacts when because of body and body internal thread ovality different internal and external threads being cooperated, particularly play fast upper shackle and repeatedly go up the shackle screw thread and scuffing can not occur and damage phenomenon, significantly improved product percent of pass.

5. adopt wedge shape and become the wide Design of Screw Thread structure of tooth with anti-tripping performance, stretch-proof load performance, the counter-bending ability of Effective Raise nipple, the high composite bearing ability of Effective Raise nipple can provide interior pressure drag and the bonding strength suitable with body.

6. adopted the plane structure design of three different taperings or angle at the bottom of the tooth top of screw thread and the tooth, but not cambered surface reduces difficulty of processing, reaches the plane and contacts with interplanar, eliminate internal and external threads under the factor affecting such as different ovalitys, improve the impact of interference fit double thread profile of tooth sealing performance.

7. adopt the type of attachment without coupling type, respectively increase the hermetically-sealed construction of a metal and metallic radial interference fit at the two ends of internal thread, externally threaded two ends of while are the identical hermetically-sealed construction that respectively increases a metal and metallic radial interference fit also.The hermetically-sealed construction of nipple is doubled, and it is not interfered each other, can effectively and significantly increase the sealing performance that nipple connects.

8. its inside and outside all hermetically-sealed constructions have all adopted and have crossed the torque shoulder structure simultaneously, and the torque shoulder structure has adopted plane or cambered surface form.Owing to increased more and crossed torque shoulder and certain interference effect is arranged between it, but can pass through its tolerance fit each other, reach fully improve its nipple moment of torsion and incompressible load-carrying ability.

9. nipple comprehensively forming by tapered thread structure, multi-sealing structure and high resistance torque structure, make it each other all in the interference fit situation, high sealing performance, counter-bending ability, incompressible load-carrying ability and high resistance torsional performance that nipple connects can have significantly effectively been increased.

10. because employing without the type of attachment of coupling type, has guaranteed cementing quality thereby effectively increased the well cementation gap.A quantity that simultaneously whole tubing and casing cylinder is threaded reduces 50%, effectively reduces the quality risk of connection of thread, improves the comprehensive quality safety factor of whole oil casing.

11. concordant design in having increased body internal thread shoulder plane length simultaneously its body internal thread torque shoulder plane and inboard wall of tube body adopting can effectively reduce the turbulent phenomenon of respective media when current in pipeline, makes energy loss be reduced to minimum.

12. the present invention is fit to oil, the gas well use of deep-well, ultradeep well, high sealing performance requirement very much.

Description of drawings

Fig. 1 is the structural representation of oil well pipe left end of the present invention.

Fig. 2 is the enlarged diagram of A part among Fig. 1.

Fig. 3 is the enlarged diagram of B part among Fig. 1.

Fig. 4 is the enlarged diagram of C part among Fig. 1.

Fig. 5 is the structural representation of oil well pipe right-hand member of the present invention.

Fig. 6 is the enlarged diagram of D part among Fig. 5.

Fig. 7 is the enlarged diagram of E part among Fig. 5.

Fig. 8 is the enlarged diagram of F part among Fig. 5.

The specific embodiment

The invention will be further described below in conjunction with specific embodiment.

A kind of without the wide wedge type thread compound of the multi-sealed change tooth of box cupling well casing structure, comprise body external thread section 1.1, body internal thread segment 1.2, oil well pipe body 1.3, the right seal section 1.5 of left seal section 1.4 external screw threads of internal thread, the right seal section 1.6 of internal thread and the left seal section 1.7 of external screw thread; Body external thread section 1.1 is the right-hand members that are connected to oil well pipe body 1.3, body external thread section 1.1 is that the right-hand member at oil well pipe body 1.3 processes, between body external thread section 1.1 and oil well pipe body 1.3, be provided with the left seal section 1.7 of external screw thread, be provided with the right seal section 1.5 of external screw thread in the right part of body external thread section 1.1, body internal thread segment 1.2 is the left ends that are connected to oil well pipe body 1.3, body internal thread segment 1.2 is that the left end at oil well pipe body 1.3 processes, between body internal thread segment 1.2 and oil well pipe body 1.3, be provided with the right seal section 1.6 of internal thread, be provided with the left seal section 1.4 of internal thread in the left part of body internal thread segment 1.2.

On described body external thread section 1.1 direction from right to left, the facewidth of described body external thread section 1.1 is gradually, and increase arranges, the space width of body external thread section 1.1 is dwindles setting gradually, the difference of adjacent two facewidth equates with the difference of adjacent two space widths, the height of each tooth of body external thread section 1.1 equates that the tapering of body external thread section 1.1 is 1:16 ~ 1:24; On the longitudinal cross-section of oil well pipe, each tooth on the body external thread section 1.1 is wedge shape, is equipped with barb in the both sides, top of each tooth; The middle top of each tooth on the body external thread section 1.1 is outer crest top land 26, the left side of outer crest top land 26 is provided with the left plane 20 of outer tooth top, the right side of outer crest top land 26 is provided with the right plane 23 of outer tooth top, link to each other by the left transition arc 37 of outer crest top land between the left plane 20 of outer tooth top and the outer crest top land 26, link to each other by the right transition arc 36 of outer crest top land between the right plane 23 of outer tooth top and the outer crest top land 26, the teeth groove middle part is external tooth bottom surface 27, external tooth bottom surface 27 is taper seat, outer crest top land 26 is taper seat, and outer crest top land 26, the tapering of external tooth bottom surface 27 equates with the tapering of body external thread section 1.1, the left side of external tooth bottom surface 27 is provided with left plane 25 at the bottom of the external tooth, the right side of external tooth bottom surface 27 is provided with right plane 22 at the bottom of the external tooth, the right side wall of each tooth is provided with outer spigot surface 24, outer spigot surface 24 is 79 ~ 85 ° with the axis angulation of oil well pipe, the left side wall of each tooth is provided with outer bearing surface 21, outer bearing surface 21 is 76 ~ 82 ° with the axis angulation of oil well pipe, external tooth bottom surface 27 with link to each other by the left transition arc 38 in external tooth bottom surface between the left plane 25 at the bottom of the external tooth, external tooth bottom surface 27 with link to each other by the right transition arc 39 in external tooth bottom surface between the right plane 22 at the bottom of the external tooth, link to each other by right circular arc 35 at the bottom of the external tooth between right plane 22 and the outer bearing surface 21 at the bottom of the external tooth, link to each other by the left circular arc 34 of outer tooth top between outer bearing surface 21 and the left plane 20 of outer tooth top, link to each other by left circular arc 33 at the bottom of the external tooth between left plane 25 and the outer spigot surface 24 at the bottom of the external tooth, link to each other by the right circular arc 32 of outer tooth top between outer spigot surface 24 and the outer tooth top outerplanar 23, left plane 51 is 10 ~ 20 ° with the axis angulation of oil well pipe at the bottom of the internal tooth, the right plane 23 of outer tooth top is 10 ~ 20 ° with the axis angulation of oil well pipe, right plane 22 is 7 ~ 17 ° with the axis angulation of oil well pipe at the bottom of the external tooth, and the left plane 20 of outer tooth top is 7 ~ 17 ° with the axis angulation of oil well pipe.

The tapering of described body external thread section 1.1 is 1:18 ~ 1:20; The number of threads of described body external thread section 1.1 is 12 ~ 30; The first buckle teeth of body external thread section 1.1 is wide to be 1.8 ~ 3.2mm; The spigot surface pitch of body external thread section 1.1 is 3.96 ~ 9.60mm; The bearing surface pitch of body external thread section 1.1 is: (it is wide that the external screw thread total length deducts 2 times of first buckle teeth)/(always detain number and deduct 1); The first buckle teeth groove width of body external thread section 1.1 is: it is wide that spigot surface pitch deducts first buckle teeth; The tooth depth of body external thread section 1.1 is 1.5 ~ 2.5mm.

On the longitudinal cross-section of oil well pipe, the first buckle teeth of body external thread section 1.1 is wide to be 1.8 ~ 3.2mm; The tooth depth of each tooth of body external thread section 1.1 is 1.5 ~ 2.5mm; The width on the left plane 20 of outer tooth top is 0.5 ~ 3.0 mm; The width of outer bearing surface 21 is 0.5 ~ 2.0 mm; The width on right plane 22 is 0.5 ~ 3.0 mm at the bottom of the external tooth; The width on the right plane 23 of outer tooth top is 0.5 ~ 3.0 mm; The width of outer spigot surface 24 is 0.5 ~ 2.0 mm; The width on left plane 25 is 0.5 ~ 3.0 mm at the bottom of the external tooth; The width of outer crest top land 26 is 0.05 ~ 6.0 mm; The width of external tooth bottom surface 27 is 0.05 ~ 6.0 mm; The radius of the right circular arc 32 of outer tooth top is 0.20 ~ 0.50mm; The radius of left circular arc 33 is 0.20 ~ 0.50mm at the bottom of the external tooth; The radius of the left circular arc 34 of outer tooth top is 0.20 ~ 0.50mm; The radius of right circular arc 35 is 0.20 ~ 0.50mm at the bottom of the external tooth; The radius of the right transition arc 36 of outer crest top land is 0.15 ~ 0.30mm; The radius of the left transition arc 37 of outer crest top land is 0.15 ~ 0.30mm; The radius of the left transition arc 38 in external tooth bottom surface is 0.15 ~ 0.30mm; The radius of the right transition arc 39 in external tooth bottom surface is 0.15 ~ 0.30mm; Angle between the axis of outer bearing surface 21 and oil well pipe is 2 ~ 6 ° less than the angle between the axis of outer spigot surface 24 and oil well pipe.

On the longitudinal cross-section of oil well pipe, the right seal section 1.5 of described external screw thread comprises outside outside outer primary sealing area 73, the outside outside secondary sealing area 75, the outside outside the 3rd sealing surface 77, the outside circular bead surface 89 and inboard wall of tube body transition face 95 outside shoulder summit cambered surface 81, the outside; Be positioned at the bottom of the external tooth of the rightmost side that primary sealing area 73 joins outside the left plane 25 and outside, secondary sealing area 75 joins outside the outer primary sealing area 73 in outside and the outside, the 3rd sealing surface 77 joins outside the outer secondary sealing area 75 in outside and the outside, shoulder summit cambered surface 81 rounding ofves outside outer the 3rd sealing surface 77 in outside and the outside, circular bead surface 89 rounding ofves outside outer shoulder summit, outside cambered surface 81 and the outside, the outer circular bead surface 89 in outside and inboard wall of tube body transition face 95, inboard wall of tube body transition face 95 joins with the inner hole wall of oil well pipe.

On the longitudinal cross-section of oil well pipe, the length of primary sealing area 73 is 3.0 ~ 6.0mm outside the described outside, and the tapering of primary sealing area 73 is greater than the tapering of body external thread section 1.1 outside the outside; The length of the outer secondary sealing area 75 in outside is 3.0 ~ 6.0mm, and secondary sealing area 75 is taper seat, outer convex globoidal or inner concave arc surface outside the outside, and when secondary sealing area 75 was cambered surface outside the outside, its corresponding central angle number of degrees were 12 ~ 18 °; The length of outer the 3rd sealing surface 77 in outside is 4.0 ~ 8.0mm, and the 3rd sealing surface 77 is taper seat, outer convex globoidal or inner concave arc surface outside the outside, and when the 3rd sealing surface 77 was cambered surface outside the outside, its corresponding central angle number of degrees were 3 ~ 9 °; The radius of outer shoulder summit, outside cambered surface 81 is: 0.2 ~ 0.5mm, and its corresponding central angle number of degrees are 50 ~ 65 °; The radius of the outer circular bead surface 89 in outside is 4.0 ~ 20.0mm, and circular bead surface 89 is taper seat, outer convex globoidal or inner concave arc surface outside the outside, and when circular bead surface 89 was cambered surface outside the outside, its corresponding central angle number of degrees were 60 ~ 85 °; The length of inboard wall of tube body transition face 95 is 5 ~ 20mm, and inboard wall of tube body transition face 95 is 5 ~ 10 ° with the axis angulation of oil well pipe; The line at outer secondary sealing area 75 two ends, outside and the axis angulation of oil well pipe are 12 ~ 18 °; The line at outer the 3rd sealing surface 77 two ends, outside and the axis angulation of oil well pipe are 3 ~ 9 °; The line at outer circular bead surface 89 two ends, outside and the axis angulation of oil well pipe are 60 ~ 85 °.

On the longitudinal cross-section of oil well pipe, the left seal section 1.7 of described external screw thread comprises in the outside in the primary sealing area 96, outside in secondary sealing area 98, the outside in the 3rd sealing surface 100, the outside circular bead surface 112 in the shoulder summit cambered surface 104 and outside; The right plane 23 of outer tooth top that is positioned at the leftmost side joins with outside primary sealing area 96, secondary sealing area 98 joins in the interior primary sealing area 96 in outside and the outside, the 3rd sealing surface 100 joins in the interior secondary sealing area 98 in outside and the outside, shoulder summit cambered surface 104 rounding ofves in the 3rd sealing surface 100 and the outside in the outside, circular bead surface 112 rounding ofves in shoulder summit cambered surface 104 and the outside in the outside, circular bead surface 112 joins by fillet with the inner hole wall of oil well pipe in the outside.

On the longitudinal cross-section of oil well pipe, the length of primary sealing area 96 is 3.0 ~ 6.0mm in the described outside, and its tapering is greater than the tapering of body external thread section 1.1; The length of secondary sealing area 98 is 3.0 ~ 6.0mm in the outside, and secondary sealing area 98 is taper seat, outer convex globoidal or inner concave arc surface in the outside, and when secondary sealing area 98 was cambered surface in the outside, its corresponding central angle number of degrees were 12 ~ 18 °; The length of the 3rd sealing surface 100 is in the outside, 4.0 ~ 8.0mm, and the 3rd sealing surface 100 is taper seat, outer convex globoidal or inner concave arc surface in the outside, when the 3rd sealing surface 100 was cambered surface in the outside, its corresponding central angle number of degrees were 3 ~ 9 °; The radius of shoulder summit cambered surface 104 is 0.2 ~ 0.5mm in the outside, and its corresponding central angle number of degrees are 50 ~ 65 °; Circular bead surface 112 is taper seat, outer convex globoidal or inner concave arc surface in the outside, and when circular bead surface 112 was cambered surface in the outside, its radius was 4.0 ~ 20.0mm, and its corresponding central angle number of degrees are 60 ~ 85 °; The line at secondary sealing area 98 two ends and the axis angulation of oil well pipe are 12 ~ 18 ° in the outside; The line at the 3rd sealing surface 100 two ends and the axis angulation of oil well pipe are 3 ~ 9 ° in the outside; The line at circular bead surface 112 two ends and the axis angulation of oil well pipe are 60 ~ 85 ° in the outside.

On described body internal thread segment 1.2 direction from left to right, the facewidth of body internal thread segment 1.2 is gradually, and increase arranges, the space width of body internal thread segment 1.2 is dwindles setting gradually, the difference of adjacent two facewidth equates with the difference of adjacent two space widths, the height of each tooth of body internal thread segment 1.2 equates that the tapering of body internal thread segment 1.2 is 1:16 ~ 1:24; On the longitudinal cross-section of oil well pipe, each tooth on the body internal thread segment 1.2 is wedge shape, is equipped with barb in the both sides, top of each tooth; The middle top of each tooth on the body internal thread segment 1.2 is interior crest top land 58, the left side of interior crest top land 58 is provided with the left plane 56 of interior tooth top, the right side of interior crest top land 58 is provided with the right plane 53 of interior tooth top, link to each other by the left transition arc 69 of interior crest top land between the left plane 56 of interior tooth top and the interior crest top land 58, link to each other by the right transition arc 70 of interior crest top land between the right plane 53 of interior tooth top and the interior crest top land 58, the teeth groove middle part is internal tooth bottom surface 57, internal tooth bottom surface 57 is taper seat, interior crest top land 58 is taper seat, and internal tooth bottom surface 57, the tapering of interior crest top land 58 equates with the tapering of body internal thread segment 1.2, the left side of internal tooth bottom surface 57 is provided with left plane 51 at the bottom of the internal tooth, the right side of internal tooth bottom surface 57 is provided with right plane 54 at the bottom of the internal tooth, the right side wall of each tooth is provided with interior spigot surface 55, interior spigot surface 55 is 79 ~ 85 ° with the axis angulation of body internal thread segment 1.2, the left side wall of each tooth is provided with interior bearing surface 52, interior bearing surface 52 is 76 ~ 82 ° with the axis angulation of body internal thread segment 1.2, link to each other by the left transition arc 68 in internal tooth bottom surface between internal tooth bottom surface 57 and the inner plane at the bottom of the internal tooth 51, link to each other by the right transition arc 67 in internal tooth bottom surface between internal tooth bottom surface 57 and the outerplanar at the bottom of the internal tooth 54, link to each other by right circular arc 63 at the bottom of the internal tooth between right plane 54 and the interior spigot surface 55 at the bottom of the internal tooth, link to each other by the left circular arc 64 of interior tooth top between interior spigot surface 55 and the left plane 56 of interior tooth top, link to each other by left circular arc 65 at the bottom of the internal tooth between left plane 51 and the interior bearing surface 52 at the bottom of the internal tooth, link to each other by the right circular arc 66 of interior tooth top between interior bearing surface 52 and the right plane 53 of interior tooth top, left plane 51 is 10 ~ 20 ° with the axis angulation of oil well pipe at the bottom of the internal tooth, the right plane 53 of interior tooth top is 10 ~ 20 ° with the axis angulation of oil well pipe, right plane 54 is 7 ~ 17 ° with the axis angulation of oil well pipe at the bottom of the internal tooth, and the left plane 56 of interior tooth top is 7 ~ 17 ° with the axis angulation of oil well pipe.

On the longitudinal cross-section of oil well pipe, the left seal section 1.4 of described internal thread comprises the outer primary sealing area 97 of inner face, the outer secondary sealing area 99 of inner face, outer the 3rd sealing surface 101 of inner face, the outer shoulder summit of inner face cambered surface 105 and the outer circular bead surface 113 of inner face; Right plane 54 joins with the outer primary sealing area 97 of inner face at the bottom of being positioned at the internal tooth of the leftmost side, the outer primary sealing area 97 of inner face joins with the outer secondary sealing area 99 of inner face, the outer secondary sealing area 99 of inner face joins with outer the 3rd sealing surface 101 of inner face, outer the 3rd sealing surface 101 of inner face and the outer shoulder summit of inner face cambered surface 105 rounding ofves, the outer shoulder summit of inner face cambered surface 105 and outer circular bead surface 113 rounding ofves of inner face, the outer circular bead surface 113 of inner face joins with the outer wall of oil well pipe.

On the longitudinal cross-section of oil well pipe, the length of the outer primary sealing area 97 of described inner face is 3.0 ~ 6.0mm, and its tapering is greater than the tapering of body internal thread segment 1.2; The length of the outer secondary sealing area 99 of inner face is 3.0 ~ 6.0mm, and the outer secondary sealing area 99 of inner face be taper seat, outer convex globoidal or inner concave arc surface, and inner face is when secondary sealing area 99 is cambered surface outward, and its corresponding central angle number of degrees are 12 ~ 18 °; The length of outer the 3rd sealing surface 101 of inner face is 4.0 ~ 8.0mm, and outer the 3rd sealing surface 101 of inner face be taper seat, outer convex globoidal or inner concave arc surface, and inner face is when the 3rd sealing surface 101 is cambered surface outward, and its corresponding central angle number of degrees are 3 ~ 9 °; The radius of the outer shoulder summit of inner face cambered surface 105 is 0.2 ~ 0.5mm, and its corresponding central angle number of degrees are 50 ~ 65 °; The outer circular bead surface 113 of inner face be taper seat, outer convex globoidal or inner concave arc surface, and the outer circular bead surface 113 of inner face is when being cambered surface, and the inner face outward radius of circular bead surface 113 is 4 ~ 20mm, and its corresponding central angle number of degrees are 60 ~ 85 °; The line at outer secondary sealing area 99 two ends of inner face and the axis angulation of oil well pipe are 10 ~ 20 °; The line at outer the 3rd sealing surface 101 two ends of inner face and the axis angulation of oil well pipe are 5 ~ 15 °; The line at outer circular bead surface 113 two ends of inner face and the axis angulation of oil well pipe are 60 ~ 85 °.

On the longitudinal cross-section of oil well pipe, the right seal section 1.6 of described internal thread comprises circular bead surface 90 in primary sealing area 74 in the inner face, the interior secondary sealing area 76 of inner face, interior the 3rd sealing surface 78 of inner face, the interior shoulder summit of inner face cambered surface 82 and the inner face; The left plane 56 of tooth top that is positioned at the rightmost side joins with inner face primary sealing area 74, primary sealing area 74 joins with the interior secondary sealing area 76 of inner face in the inner face, secondary sealing area 76 joins with interior the 3rd sealing surface 78 of inner face in the inner face, the 3rd sealing surface 78 and the interior shoulder summit of inner face cambered surface 82 rounding ofves in the inner face, shoulder summit cambered surface 82 and interior circular bead surface 90 rounding ofves of inner face in the inner face, circular bead surface 90 joins by fillet with the inner hole wall of oil well pipe in the inner face.

On the longitudinal cross-section of oil well pipe, the length of primary sealing area 74 is 3.0 ~ 6.0mm in the described inner face, and its tapering is greater than the tapering of body internal thread segment 1.2; The length of secondary sealing area 76 is 3.0 ~ 6.0mm in the inner face, and secondary sealing area 76 be taper seat, outer convex globoidal or inner concave arc surface in the inner face, and the interior secondary sealing area 76 of inner face is when being cambered surface, and its corresponding central angle number of degrees are 12 ~ 18 °; The length of the 3rd sealing surface 78 is 4.0 ~ 8.0mm in the inner face, and the 3rd sealing surface 78 be taper seat, outer convex globoidal or inner concave arc surface in the inner face, and interior the 3rd sealing surface 78 of inner face is when being cambered surface, and its corresponding central angle number of degrees are 3 ~ 9 °; The radius of shoulder summit cambered surface 82 is 0.2 ~ 0.5mm in the inner face, and its corresponding central angle number of degrees are 50 ~ 65 °; Circular bead surface 90 be taper seat, outer convex globoidal or inner concave arc surface in the inner face, and the interior circular bead surface 90 of inner face is when being cambered surface, and its radius is 4 ~ 20mm, and its corresponding central angle number of degrees are 60 ~ 85 °; The line at secondary sealing area 76 two ends and the axis angulation of oil well pipe are 10 ~ 20 ° in the inner face; The line at the 3rd sealing surface 78 two ends and the axis angulation of oil well pipe are 5 ~ 15 ° in the inner face; The line at circular bead surface 90 two ends and the axis angulation of oil well pipe are 60 ~ 85 ° in the inner face.

The number of threads of described body internal thread segment 1.2 is 12 ~ 30; The first buckle teeth well width of body internal thread segment 1.2 is 1.8 ~ 3.2mm; The spigot surface pitch of body internal thread segment 1.2 is 3.96 ~ 9.60; The bearing surface pitch of body internal thread segment 1.2 equals: (the internal thread total length deducts 2 times of first buckle teeth groove widths)/(always detain number and deduct 1); The first buckle teeth of body internal thread segment 1.2 is wide to be: spigot surface pitch deducts first buckle teeth groove width; The tooth depth of body internal thread segment 1.2 is: 1.5 ~ 2.5mm.

Body external thread section 1.1 is identical with the thread parameter major part of body internal thread segment 1.2, and just tolerance is different, for satisfying the interference fit requirement between the internal and external threads profile of tooth.

The total length of body external thread section 1.1 requires identical with the overall length dimension of body internal thread segment 1.2, their length is in 50 ~ 160mm scope, according to the pipe wall thickness with external diameter and different, can be with reference to API SPEC 5B " processing of sleeve pipe, oil pipe and line pipe thread, measurement and inspection specification ".

Body external thread section 1.1 and body internal thread segment 1.2 ridge numbers are according to the scope of full flight length and tooth is wide and the size of pitch is determined the concrete tooth number of screw thread preferably to be controlled between 12 ~ 30 teeth selected measuring when being the screw thread comprehensive Design.

The tapering of body external thread section 1.1 is identical with the tapering of body internal thread segment 1.2, and the tapering of the tapering of outer crest top land 26 and external tooth bottom surface 27 is identical with the tapering of the tapering of internal tooth bottom surface 57 and interior crest top land 58.

Requiring of the outside buckle teeth facewidth and interior first buckle teeth groove width is identical.The multiple of the outside buckle teeth facewidth requires identical with the multiple of interior first buckle teeth groove width.The pitch of outer spigot surface 24 requires identical with the pitch of interior spigot surface 55.The pitch of outer bearing surface 21 requires identical with the pitch of interior bearing surface 52.

The outside buckle teeth facewidth is identical with the width requirement of interior first buckle teeth groove width.Its follow-up external screw thread tooth width recruitment and follow-up internal thread alveolus width recruitment its both require identical.

The pitch of outer bearing surface 21 requires identical with the pitch of interior bearing surface 52.

Outside buckle teeth groove width is: the pitch of outer spigot surface 24 deducts the width of the outside buckle teeth facewidth, and its follow-up alveolus width will reduce gradually, and its decrease is the difference that outer bearing surface pitch deducts outer spigot surface pitch, but can not be less than 0.02mm.The interior first buckle teeth facewidth is: the pitch of interior spigot surface 55 deducts interior first buckle teeth groove width width, and is identical with it.

The wide recruitment of the tooth of body external thread section 1.1 is identical with the alveolus width reduction, the pitch of the pitch of outer bearing surface 21 and outer spigot surface 24 all remains unchanged, and what gradually change is tooth width and alveolus width, guarantees that screwing of internal and external threads is smooth and easy without interfering.The wide recruitment of the alveolus of body internal thread segment 1.2 is identical with the tooth width decrease, the pitch of the pitch of interior bearing surface 52 and interior spigot surface 55 all remains unchanged, and what gradually change is tooth width and alveolus width, guarantees that screwing of internal and external threads is smooth and easy without interfering.Guaranteed that its internal and external threads normally cooperates.

The tooth depth of body external thread section 1.1 is identical with the tooth depth of body internal thread segment 1.2, and they are between 1.5 ~ 2.5mm, at the bottom of the tooth with parallel at the bottom of the tooth.

The axis angulation of outer bearing surface 21 and oil well pipe keeps 2 ~ 6 ° difference greater than the axis angulation of outer spigot surface 24 with oil well pipe between them.The axis angulation of interior bearing surface 52 and oil well pipe keeps 2 ~ 6 ° difference greater than the axis angulation of interior spigot surface 55 with oil well pipe between them, both are identical, forms wedge shape thread form angle.

The left circular arc of the right circular arc 32 of outer tooth top and outer tooth top 34 is identical, its arc radius greater than internal tooth at the bottom of right circular arc 63 be 0.05 ~ 0.20mm with left circular arc 65 radiuses at the bottom of the internal tooth.Simultaneously, left circular arc 33 is identical with right circular arc at the bottom of the external tooth 35 at the bottom of the external tooth, and its arc radius is 0.05 ~ 0.20mm greater than the left circular arc 64 of interior tooth top with right circular arc 66 radiuses of interior tooth top.The touching damage that occurs when eliminating its interference fit scratches phenomenon.

The right transition arc 36 of outer crest top land, the left transition arc 37 of outer crest top land and the left transition arc 38 in external tooth bottom surface, the right transition arc 39 in external tooth bottom surface, the right transition arc 67 in internal tooth bottom surface, the left transition arc 68 in internal tooth bottom surface and the left transition arc 69 of interior crest top land, right transition arc 70 radiuses of interior crest top land are all identical, and their radius is 0.20 ~ 0.50mm.

The mutual interference fit requirement of the right seal section 1.5 of external screw thread and the right seal section 1.6 of internal thread;

In the inner face outside primary sealing area 74 and the outside tapering, the length requirement of primary sealing area 73 all identical, the internal diameter of primary sealing area 74 is less than the external diameter of primary sealing area outside the outside 73 in the inner face, their radial diameter Deviation Control is at 0.20 ~ 1.00mm, and axially satisfied and radial interference fit reaches the high sealing performance requirement.

Secondary sealing area 75 arc radius outside secondary sealing area 76 and the outside in the inner face, length requirement are all identical, can be inner concave arc surface and outer convex globoidal fit form or outer convex globoidal and inner concave arc surface fit form.The line at secondary sealing area 76 two ends equates with the radius requirement of secondary sealing area 75 outside the outside with the axis angulation of oil well pipe, the radius of the interior secondary sealing area 76 of inner face with the line at outer secondary sealing area 75 two ends, outside with the axis angulation of oil well pipe in the inner face, satisfies axial transitions cooperation requirement.The radius of secondary sealing area 76 is less than the radial diameter of the radius of secondary sealing area outside the outside 75 in the inner face, and Deviation Control satisfies radial interference fit and reaches the high sealing performance requirement at 0.20 ~ 1.00mm.

The 3rd sealing surface 77 arc radius outside the 3rd sealing surface 78 and the outside in the inner face, length requirement are all identical, and they can be that inner concave arc surface cooperates with outer convex globoidal or outer convex globoidal and inner concave arc surface fit form.The line at the 3rd sealing surface 78 two ends equates with the radius requirement of the 3rd sealing surface 77 outside the outside with the axis angulation of oil well pipe, the radius of interior the 3rd sealing surface 78 of inner face with the line at outer the 3rd sealing surface 77 two ends, outside with the axis angulation of oil well pipe in the inner face, satisfies axial transitions cooperation requirement.The radius of the 3rd sealing surface 78 is less than the radial diameter of the radius of the 3rd sealing surface 77 outside the outside in the inner face, and their Deviation Control satisfies radial interference fit and reaches the high sealing performance requirement at 0.20 ~ 1.00mm.

Shoulder thickness equates with shoulder thickness requirement outside the outside in the inner face, satisfy and cooperate rear body inner face internal thread torque shoulder plane and concordant the getting final product of body inner face inwall, can effectively reduce the turbulent phenomenon of respective media when current in the pipeline inner face, make energy loss be reduced to minimum.

The radius of shoulder summit cambered surface 82 is less than or equal to the radius of outer shoulder summit, outside cambered surface 81 in the inner face, its Deviation Control is in the scope of 0.0 ~ 0.2mm, plan satisfies that its summit is not damaged after interference fit, to the injury of sealing surface, number of times and the relevant matching property of intending the upper shackle of increase are unaffected when preventing shackle.

The axis angulation of the line at circular bead surface 90 two ends and oil well pipe is less than the line at 89 two ends of circular bead surface outside the outside and the axis angulation of oil well pipe in the inner face, its deviation all is controlled at 0.5 ~ 1.5 ° scope, with 0.5 ~ 1.0 ° of the best, satisfy the state of plastic deformation that the inside and outside shoulder of inner face causes and be issued to interference fit in the tight situation of machine, improve its torque resistant performance requirement.

In the inner face outside circular bead surface 90 and the outside fit form of circular bead surface 89 three kinds of taper seat and taper seat fit form, inner concave arc surface and outer convex globoidal fit form and outer convex globoidal and inner concave arc surface fit forms are arranged.Both cooperate, and the radius requirement equates when adopting cambered surface.

The 3rd sealing surface 77 has two kinds to be shaped as outer convex globoidal or inner concave arc surface outside the outer secondary sealing area 75 in outside, the outside, the outer circular bead surface 89 in outside has three kinds of shapes: taper seat, outer convex globoidal or inner concave arc surface, it can carry out difform combination each other, form the sealing surface of various structures form, enumerate no longer one by one at this, its any form sealing surface structure combination is all in this patent claim scope.

Secondary sealing area 76, interior the 3rd sealing surface 78 of inner face have two kinds of shapes in the inner face: outer convex globoidal or inner concave arc surface, circular bead surface 90 has three kinds of shapes in the inner face: taper seat, outer convex globoidal or inner concave arc surface, it can carry out difform combination each other, form the sealing surface of various structures form, enumerate no longer one by one at this, its any form sealing surface structure combination is all in this patent claim scope.

Any combining form structure of the right seal section 1.5 of external screw thread must be identical with the combining form structural requirement of the right seal section 1.6 of internal thread, intends the satisfied interference fit of can carrying out smoothly between the two and reach high sealing performance and cross torsional performance.

The left seal section 1.4 of internal thread and the left seal section 1.7 mutual interference fit requirements of external screw thread;

Primary sealing area 96 is all identical with tapering, the length requirement of the outer primary sealing area 97 of inner face in the outside, the external diameter internal diameter of the outer primary sealing area 97 of inner face is less than the external diameter of primary sealing area in the outside 96, their radial diameter Deviation Control is at 0.20 ~ 1.00mm, and axially satisfied and radial interference fit reaches the high sealing performance requirement.

Secondary sealing area 98 arc radius in the outer secondary sealing area 99 of inner face and the outside, length requirement are all identical, can inner concave arc surface and outer convex globoidal fit form or outer convex globoidal and inner concave arc surface fit form.In the line at outer secondary sealing area 99 two ends of inner face and the axis angulation of oil well pipe and the outside axis angulation of the line at secondary sealing area 98 two ends and oil well pipe, inner face outward in radius and the outside of secondary sealing area 99 radius of secondary sealing area require to equate, satisfy axial transitions cooperation requirement.Outer secondary sealing area 99 radial diameter of inner face are less than the radial diameter of the radius 108 of secondary sealing area in the outside, and their Deviation Control satisfies radial interference fit and reaches the high sealing performance requirement at 0.20 ~ 1.00mm.

The 3rd sealing surface 100 arc radius in outer the 3rd sealing surface 101 of inner face and the outside, length requirement are all identical, can inner concave arc surface and outer convex globoidal fit form or outer convex globoidal and inner concave arc surface fit form.In the line at outer the 3rd sealing surface 101 two ends of inner face and the axis angulation of oil well pipe and the outside axis angulation of the line at the 3rd sealing surface 100 two ends and oil well pipe, inner face outward in radius and the outside of the 3rd sealing surface 101 radius of the 3rd sealing surface 100 require to equate, satisfy axial transitions cooperation requirement.The radial diameter of outer the 3rd sealing surface 101 of inner face less than the 3rd sealing surface 100 in the outside radial diameter, their Deviation Control satisfies radial interference fit and reaches the high sealing performance requirement at 0.20 ~ 1.00mm.

The outer shoulder thickness of inner face equates with shoulder thickness requirement in the outside, satisfy and cooperate rear body inner face internal thread torque shoulder plane and concordant the getting final product of body inner face inwall, can effectively reduce the turbulent phenomenon of respective media when current in the pipeline inner face, make energy loss be reduced to minimum.

The radius of the outer shoulder summit of inner face cambered surface 105 is less than or equal to the radius of shoulder summit cambered surface 104 in the outside, its Deviation Control is in the scope of 0.0 ~ 0.2mm, plan satisfies that its summit is not damaged after interference fit, to the injury of sealing surface, number of times and the relevant matching property of intending the upper shackle of increase are unaffected when preventing shackle.

The axis angulation of the line at circular bead surface 112 two ends and oil well pipe is less than the line at outer circular bead surface 113 two ends of inner face and the axis angulation of oil well pipe in the outside, its deviation all is controlled at 0.5 ° ~ 1.5 ° scope, with 0.5 ~ 1.0 ° of the best, satisfy the state of plastic deformation that the inside and outside shoulder of inner face causes and be issued to interference fit in the tight situation of machine, improve its torque resistant performance requirement.

The fit form of circular bead surface 112 has three kinds of plane and plane fit form, inner concave arc surface and outer convex globoidal fit form and outer convex globoidal and inner concave arc surface fit forms in the outer circular bead surface 113 of inner face and the outside.Both cooperate, and the radius requirement equates when adopting cambered surface.

The 3rd sealing surface 100 has two kinds of shapes in the interior secondary sealing area 98 in outside, the outside: circular bead surface 112 has three kinds of shapes in outer convex globoidal or inner concave arc surface, the outside: taper seat, outer convex globoidal or inner concave arc surface, it can carry out difform combination each other, form the sealing surface of various structures form, enumerate no longer one by one at this, its any form sealing surface structure combination is all in this patent claim scope.

The outer secondary sealing area 99 of inner face, outer the 3rd sealing surface 101 of inner face have two kinds of shapes: outer convex globoidal or inner concave arc surface; The outer circular bead surface 113 of inner face has three kinds of shapes: taper seat, outer convex globoidal or inner concave arc surface, it can carry out difform combination each other, form the sealing surface of various structures form, enumerate no longer one by one at this, its any form sealing surface structure combination is all in this patent claim scope.

Any combining form structure of the left seal section 1.7 of external screw thread must be identical with the combining form structural requirement of the left seal section 1.4 of internal thread, intends the satisfied interference fit of can carrying out smoothly between the two and reach high sealing performance and cross torsional performance.

The present invention in use concrete operations is as follows:

This kind is that two ends with a steel pipe are processed as respectively body external thread section 1.1 and body internal thread segment 1.2 without the wide wedge thread oil-well pipe joint of the multi-sealed special change tooth of box cupling, saved the type of attachment of box cupling.Significantly reduce whole tubing and casing cylinder and be threaded a little, reduced quality risk, improved safety factor.It mainly is that vertically to carry out junctor on oil field derrick tight that this kind nipple connects, at first the external threaded surface of body external thread section 1.1 is evenly smeared one deck oil dedicated thread compound, again body internal thread segment 1.2 is inserted in first on the body external thread section 1.1, overlap and fashionablely body internal thread segment 1.2 and body external thread section 1.1 should be carried out the screw thread make-up, should light and slow the internal thread tooth top be contacted with at the bottom of the external screw thread tooth during hitch, owing to adopted the unequal screw thread of pitch of thread form bearing surface and thread form spigot surface to screw form, the tooth of its internal threaded end screw thread and external screw thread end screw thread wide less than alveolus wide be that uniform pitch becomes the wide form of thread of tooth, its make-up is very convenient and simple, substantially the thread alternating phenomenon can not occur.Be inserted in first about 2 ~ 4 buttons, beginning machinery is twisted and is connect.

Because the tolerance of some parameters such as the tapering of screw thread, pitch, thread form, tooth depth is different, need to use high pulling torque/high moment of torsion to carry out machine and twist and connect, should adopt at a slow speed or carry out slowly.Be issued to interference fit between thread form in the situation of uniform stressed at the bottom of the bearing surface of each tooth and spigot surface and the tooth top tooth this moment in reach, thread form sealing structure performance significantly improves, and the impact that the different double threads of internal and external threads ovality cooperate is very little.Simultaneously, the right seal section 1.5 of external screw thread reaches interference fit with the right seal section 1.6 of internal thread, and the left seal section 1.7 of external screw thread has reached interference fit with the left seal section 1.4 of internal thread.Twist to connect at machine and detect the gap length after the shoulder interference fit outside it with ultra-thin special blade after finishing, any slit must not be arranged, the point of a knife insertion of blade can not be got final product with the circumference detection.Make its nipple have high composite bearing ability this moment, effectively and significantly increased the requirement of highly dense front cover performance, high resistance torsional performance and compressive load ability and tensile load ability.

Same fastening method with its body and body be connected to form thousands of rice bran oils, casing string satisfies the requirement of oil gas field production and application.

Operating principle: carry out some be connected to form casing strings, casing string with the body external screw thread with the form of being threaded by the body internal thread between body and the body.Its inner overall space passage that forms a UNICOM, the power that extraneous high strength complexity can be born in the inner passage applies and does not reveal or damage, and satisfies the requirement of oil gas field production and application.

Screw thread of the present invention has adopted the two barb tooth side shapes of wedge shape, pitch has adopted thread form bearing surface and the unequal helicitic texture form of thread form spigot surface pitch, to cause simultaneously the regular gradually increase of its tooth width, what the alveolus width was regular reduces gradually, and its recruitment equates with decrease.

The present invention adopts the type of attachment without coupling type, respectively increases the hermetically-sealed construction of a metal and metallic radial interference fit at the two ends of internal thread, and externally threaded two ends of while are the identical hermetically-sealed construction that respectively increases a metal and metallic radial interference fit also.Its inside and outside all hermetically-sealed constructions have all adopted crosses the torque shoulder structure, and the torque shoulder structure has adopted plane or cambered surface form.Nipple comprehensively is comprised of tapered thread structure, multi-sealing structure and high resistance torque structure, make it each other all in the interference fit situation, high sealing performance, counter-bending ability, incompressible load-carrying ability and high resistance torsional performance that nipple connects can have significantly effectively been increased.The combination property that nipple is connected is promoted to higher level.Employing has guaranteed cementing quality without the type of attachment of coupling type thereby effectively increased the well cementation gap.A quantity that simultaneously whole tubing and casing cylinder is threaded reduces 50%, effectively reduces the quality risk of connection of thread, improves the comprehensive quality safety factor of whole oil casing.

Claims (10)

1. one kind without the wide wedge type thread compound of the multi-sealed change tooth of box cupling well casing structure, comprises body external thread section (1.1), body internal thread segment (1.2), oil well pipe body (1.3), the right seal section of the left seal section of internal thread (1.4) external screw thread (1.5), the right seal section of internal thread (1.6) and the left seal section of external screw thread (1.7); Body external thread section (1.1) is the right-hand member that is connected to oil well pipe body (1.3), upward and between the oil well pipe body (1.3) be provided with the left seal section of external screw thread (1.7) at body external thread section (1.1), be provided with the right seal section of external screw thread (1.5) in the right part of body external thread section (1.1), body internal thread segment (1.2) is the left end that is connected to oil well pipe body (1.3), between body internal thread segment (1.2) and oil well pipe body (1.3), be provided with the right seal section of internal thread (1.6), be provided with the left seal section of internal thread (1.4) in the left part of body internal thread segment (1.2).

2. as claimed in claim 1 without the wide wedge type thread compound of the multi-sealed change tooth of box cupling well casing structure, it is characterized in that: on described body external thread section (1.1) direction from right to left, the facewidth of described body external thread section (1.1) is gradually, and increase arranges, the space width of body external thread section (1.1) is dwindles setting gradually, the difference of adjacent two facewidth equates with the difference of adjacent two space widths, the height of each tooth of body external thread section (1.1) equates that the tapering of body external thread section (1.1) is 1:16 ~ 1:24; On the longitudinal cross-section of oil well pipe, each tooth on the body external thread section (1.1) is wedge shape, is equipped with barb in the both sides, top of each tooth; The middle top of each tooth on the body external thread section (1.1) is outer crest top land (26), the left side of outer crest top land (26) is provided with the left plane of outer tooth top (20), the right side of outer crest top land (26) is provided with the right plane of outer tooth top (23), link to each other by the left transition arc of outer crest top land (37) between the left plane of outer tooth top (20) and the outer crest top land (26), link to each other by the right transition arc of outer crest top land (36) between the right plane of outer tooth top (23) and the outer crest top land (26), the teeth groove middle part is external tooth bottom surface (27), external tooth bottom surface (27) is taper seat, outer crest top land (26) is taper seat, and outer crest top land (26), the tapering of external tooth bottom surface (27) equates with the tapering of body external thread section (1.1), the left side of external tooth bottom surface (27) is provided with left plane (25) at the bottom of the external tooth, the right side of external tooth bottom surface (27) is provided with right plane (22) at the bottom of the external tooth, the right side wall of each tooth is provided with outer spigot surface (24), outer spigot surface (24) is 79 ~ 85 ° with the axis angulation of oil well pipe, the left side wall of each tooth is provided with outer bearing surface (21), outer bearing surface (21) is 76 ~ 82 ° with the axis angulation of oil well pipe, external tooth bottom surface (27) with link to each other by the left transition arc in external tooth bottom surface (38) between left plane (25) at the bottom of the external tooth, external tooth bottom surface (27) with link to each other by the right transition arc in external tooth bottom surface (39) between right plane (22) at the bottom of the external tooth, link to each other by right circular arc (35) at the bottom of the external tooth between right plane (22) and the outer bearing surface (21) at the bottom of the external tooth, link to each other by the left circular arc of outer tooth top (34) between outer bearing surface (21) and the left plane of outer tooth top (20), link to each other by left circular arc (33) at the bottom of the external tooth between left plane (25) and the outer spigot surface (24) at the bottom of the external tooth, link to each other by the right circular arc of outer tooth top (32) between outer spigot surface (24) and the outer tooth top outerplanar (23), at the bottom of the external tooth at the bottom of the internal tooth of left plane (25) the axis angulation of left plane (51) and oil well pipe be 10 ~ 20 °, the right plane of outer tooth top (23) is 10 ~ 20 ° with the axis angulation of oil well pipe, right plane (22) are 7 ~ 17 ° with the axis angulation of oil well pipe at the bottom of the external tooth, and the left plane of outer tooth top (20) is 7 ~ 17 ° with the axis angulation of oil well pipe.

3. as claimed in claim 1 without the wide wedge type thread compound of the multi-sealed change tooth of box cupling well casing structure, it is characterized in that: the tapering of described body external thread section (1.1) is 1:18 ~ 1:20; The number of threads of described body external thread section (1.1) is 12 ~ 30; The first buckle teeth of body external thread section (1.1) is wide to be 1.8 ~ 3.2mm; The spigot surface pitch of body external thread section (1.1) is 3.96 ~ 9.60mm; The bearing surface pitch of body external thread section (1.1) is: (it is wide that the external screw thread total length deducts 2 times of first buckle teeth)/(always detain number and deduct 1); The first buckle teeth groove width of body external thread section (1.1) is: it is wide that spigot surface pitch deducts first buckle teeth; The tooth depth of body external thread section (1.1) is 1.5 ~ 2.5mm.

4. as claimed in claim 1 without the wide wedge type thread compound of the multi-sealed change tooth of box cupling well casing structure, it is characterized in that: on the longitudinal cross-section of oil well pipe, the first buckle teeth of body external thread section (1.1) is wide to be 1.8 ~ 3.2mm; The tooth depth of each tooth of body external thread section (1.1) is 1.5 ~ 2.5mm; The width on the left plane of outer tooth top (20) is 0.5 ~ 3.0 mm; The width of outer bearing surface (21) is 0.5 ~ 2.0 mm; The width of right plane (22) is 0.5 ~ 3.0 mm at the bottom of the external tooth; The width on the right plane of outer tooth top (23) is 0.5 ~ 3.0 mm; The width of outer spigot surface (24) is 0.5 ~ 2.0 mm; The width of left plane (25) is 0.5 ~ 3.0 mm at the bottom of the external tooth; The width of outer crest top land (26) is 0.05 ~ 6.0 mm; The width of external tooth bottom surface (27) is 0.05 ~ 6.0 mm; The radius of the right circular arc of outer tooth top (32) is 0.20 ~ 0.50mm; The radius of left circular arc (33) is 0.20 ~ 0.50mm at the bottom of the external tooth; The radius of the left circular arc of outer tooth top (34) is 0.20 ~ 0.50mm; The radius of right circular arc (35) is 0.20 ~ 0.50mm at the bottom of the external tooth; The radius of the right transition arc of outer crest top land (36) is 0.15 ~ 0.30mm; The radius of the left transition arc of outer crest top land (37) is 0.15 ~ 0.30mm; The radius of the left transition arc in external tooth bottom surface (38) is 0.15 ~ 0.30mm; The radius of the right transition arc in external tooth bottom surface (39) is 0.15 ~ 0.30mm; Angle between the axis of outer bearing surface (21) and oil well pipe is 2 ~ 6 ° less than the angle between the axis of outer spigot surface (24) and oil well pipe.

5. as claimed in claim 1 without the wide wedge type thread compound of the multi-sealed change tooth of box cupling well casing structure, it is characterized in that: on the longitudinal cross-section of oil well pipe, the right seal section of described external screw thread (1.5) comprises outside outside outer primary sealing area (73), the outside outside secondary sealing area (75), the outside outside the 3rd sealing surface (77), the outside circular bead surface (89) and inboard wall of tube body transition face (95) outside shoulder summit cambered surface (81), the outside; Be positioned at the bottom of the external tooth of the rightmost side that primary sealing area (73) joins outside the left plane (25) and outside, secondary sealing area (75) joins outside the outer primary sealing area in outside (73) and the outside, the 3rd sealing surface (77) joins outside the outer secondary sealing area in outside (75) and the outside, shoulder summit cambered surface (81) rounding off outside outer the 3rd sealing surface (77) in outside and the outside, circular bead surface (89) rounding off outside outside outer shoulder summit cambered surface (81) and the outside, the outer circular bead surface in outside (89) and inboard wall of tube body transition face (95), inboard wall of tube body transition face (95) joins with the inner hole wall of oil well pipe; And the length of primary sealing area outside the described outside (73) is 3.0 ~ 6.0mm, and the tapering of primary sealing area outside the outside (73) is greater than the tapering of body external thread section (1.1); The length of the outer secondary sealing area in outside (75) is 3.0 ~ 6.0mm, and secondary sealing area outside the outside (75) is taper seat, outer convex globoidal or inner concave arc surface, and when secondary sealing area (75) was cambered surface outside the outside, its corresponding central angle number of degrees were 12 ~ 18 °; The length of outer the 3rd sealing surface (77) in outside is 4.0 ~ 8.0mm, and the 3rd sealing surface (77) is taper seat, outer convex globoidal or inner concave arc surface outside the outside, and when the 3rd sealing surface (77) was cambered surface outside the outside, its corresponding central angle number of degrees were 3 ~ 9 °; The radius of outside outer shoulder summit cambered surface (81) is: 0.2 ~ 0.5mm, and its corresponding central angle number of degrees are 50 ~ 65 °; The radius of the outer circular bead surface in outside (89) is 4.0 ~ 20.0mm, and circular bead surface outside the outside (89) is taper seat, outer convex globoidal or inner concave arc surface, and when circular bead surface (89) was cambered surface outside the outside, its corresponding central angle number of degrees were 60 ~ 85 °; The length of inboard wall of tube body transition face (95) is 5 ~ 20mm, and inboard wall of tube body transition face (95) is 5 ~ 10 ° with the axis angulation of oil well pipe; The line at outer secondary sealing area (75) two ends, outside and the axis angulation of oil well pipe are 12 ~ 18 °; The line at outer the 3rd sealing surface (77) two ends, outside and the axis angulation of oil well pipe are 3 ~ 9 °; The line at outer circular bead surface (89) two ends, outside and the axis angulation of oil well pipe are 60 ~ 85 °.

6. as claimed in claim 1 without the wide wedge type thread compound of the multi-sealed change tooth of box cupling well casing structure, it is characterized in that: on the longitudinal cross-section of oil well pipe, the left seal section of described external screw thread (1.7) comprises in the outside in the primary sealing area (96), outside in secondary sealing area (98), the outside in the 3rd sealing surface (100), the outside circular bead surface (112) in the shoulder summit cambered surface (104) and outside; The right plane of outer tooth top (23) that is positioned at the leftmost side joins with outside primary sealing area (96), secondary sealing area (98) joins in the interior primary sealing area (96) in outside and the outside, the 3rd sealing surface (100) joins in the interior secondary sealing area (98) in outside and the outside, shoulder summit cambered surface (104) rounding off in the 3rd sealing surface (100) and the outside in the outside, circular bead surface (112) rounding off in shoulder summit cambered surface (104) and the outside in the outside, circular bead surface in the outside (112) joins by fillet with the outer wall of oil well pipe; And the length of primary sealing area (96) is 3.0 ~ 6.0mm in the described outside, and its tapering is greater than the tapering of body external thread section (1.1); The length of secondary sealing area (98) is 3.0 ~ 6.0mm in the outside, and secondary sealing area in the outside (98) is taper seat, outer convex globoidal or inner concave arc surface, and when secondary sealing area (98) was cambered surface in the outside, its corresponding central angle number of degrees were 12 ~ 18 °; The length of the 3rd sealing surface (100) is in the outside, 4.0 ~ 8.0mm, and the 3rd sealing surface (100) is taper seat, outer convex globoidal or inner concave arc surface in the outside, when the 3rd sealing surface (100) was cambered surface in the outside, its corresponding central angle number of degrees were 3 ~ 9 °; The radius of shoulder summit cambered surface (104) is 0.2 ~ 0.5mm in the outside, and its corresponding central angle number of degrees are 50 ~ 65 °; Circular bead surface (112) is taper seat, outer convex globoidal or inner concave arc surface in the outside, and when circular bead surface in the outside (112) was cambered surface, its radius was 4.0 ~ 20.0mm, and its corresponding central angle number of degrees are 60 ~ 85 °; The line at secondary sealing area (98) two ends and the axis angulation of oil well pipe are 12 ~ 18 ° in the outside; The line at the 3rd sealing surface (100) two ends and the axis angulation of oil well pipe are 3 ~ 9 ° in the outside; The line at circular bead surface (112) two ends and the axis angulation of oil well pipe are 60 ~ 85 ° in the outside.

7. as claimed in claim 1 without the wide wedge type thread compound of the multi-sealed change tooth of box cupling well casing structure, it is characterized in that: on described body internal thread segment (1.2) direction from left to right, the facewidth of body internal thread segment (1.2) is gradually, and increase arranges, the space width of body internal thread segment (1.2) is dwindles setting gradually, the difference of adjacent two facewidth equates with the difference of adjacent two space widths, the height of each tooth of body internal thread segment (1.2) equates that the tapering of body internal thread segment (1.2) is 1:16 ~ 1:24; On the longitudinal cross-section of oil well pipe, each tooth on the body internal thread segment (1.2) is wedge shape, is equipped with barb in the both sides, top of each tooth; The middle top of each tooth on the body internal thread segment (1.2) is interior crest top land (58), the left side of interior crest top land (58) is provided with the left plane of interior tooth top (56), the right side of interior crest top land (58) is provided with the right plane of interior tooth top (53), link to each other by the left transition arc of interior crest top land (69) between the left plane of interior tooth top (56) and the interior crest top land (58), link to each other by the right transition arc of interior crest top land (70) between the right plane of interior tooth top (53) and the interior crest top land (58), the teeth groove middle part is internal tooth bottom surface (57), internal tooth bottom surface (57) is taper seat, interior crest top land (58) is taper seat, and internal tooth bottom surface (57), the tapering of interior crest top land (58) equates with the tapering of body internal thread segment (1.2), the left side of internal tooth bottom surface (57) is provided with left plane (51) at the bottom of the internal tooth, the right side of internal tooth bottom surface (57) is provided with right plane (54) at the bottom of the internal tooth, the right side wall of each tooth is provided with interior spigot surface (55), interior spigot surface (55) is 79 ~ 85 ° with the axis angulation of body internal thread segment (1.2), the left side wall of each tooth is provided with interior bearing surface (52), interior bearing surface (52) is 76 ~ 82 ° with the axis angulation of body internal thread segment (1.2), link to each other by the left transition arc in internal tooth bottom surface (68) between internal tooth bottom surface (57) and the inner plane at the bottom of the internal tooth (51), link to each other by the right transition arc in internal tooth bottom surface (67) between internal tooth bottom surface (57) and the outerplanar at the bottom of the internal tooth (54), link to each other by right circular arc (63) at the bottom of the internal tooth between right plane (54) and the interior spigot surface (55) at the bottom of the internal tooth, link to each other by the left circular arc of interior tooth top (64) between interior spigot surface (55) and the left plane of interior tooth top (56), link to each other by left circular arc (65) at the bottom of the internal tooth between left plane (51) and the interior bearing surface (52) at the bottom of the internal tooth, link to each other by the right circular arc of interior tooth top (66) between interior bearing surface (52) and the right plane of interior tooth top (53), left plane (51) are 10 ~ 20 ° with the axis angulation of oil well pipe at the bottom of the internal tooth, the right plane of interior tooth top (53) is 10 ~ 20 ° with the axis angulation of oil well pipe, right plane (54) are 7 ~ 17 ° with the axis angulation of oil well pipe at the bottom of the internal tooth, and the left plane of interior tooth top (56) is 7 ~ 17 ° with the axis angulation of oil well pipe.

8. as claimed in claim 1 without the wide wedge type thread compound of the multi-sealed change tooth of box cupling well casing structure, it is characterized in that: on the longitudinal cross-section of oil well pipe, the left seal section of described internal thread (1.4) comprises the outer primary sealing area (97) of inner face, the outer secondary sealing area (99) of inner face, outer the 3rd sealing surface (101) of inner face, the outer shoulder summit cambered surface (105) of inner face and the outer circular bead surface (113) of inner face; Right plane (54) joins with the outer primary sealing area (97) of inner face at the bottom of being positioned at the internal tooth of the leftmost side, the outer primary sealing area (97) of inner face joins with the outer secondary sealing area (99) of inner face, the outer secondary sealing area (99) of inner face joins with outer the 3rd sealing surface (101) of inner face, outer the 3rd sealing surface (101) of inner face and outer shoulder summit cambered surface (105) rounding off of inner face, the outer shoulder summit cambered surface (105) of inner face and outer circular bead surface (113) rounding off of inner face, the outer circular bead surface (113) of inner face joins with the outer wall of oil well pipe; And the length of the outer primary sealing area (97) of described inner face is 3.0 ~ 6.0mm, and its tapering is greater than the tapering of body internal thread segment (1.2); The length of the outer secondary sealing area (99) of inner face is 3.0 ~ 6.0mm, and the outer secondary sealing area (99) of inner face be taper seat, outer convex globoidal or inner concave arc surface, and inner face is when secondary sealing area (99) is cambered surface outward, and its corresponding central angle number of degrees are 12 ~ 18 °; The length of outer the 3rd sealing surface (101) of inner face is 4.0 ~ 8.0mm, and outer the 3rd sealing surface (101) of inner face be taper seat, outer convex globoidal or inner concave arc surface, and inner face is when the 3rd sealing surface (101) is cambered surface outward, and its corresponding central angle number of degrees are 3 ~ 9 °; The radius of the outer shoulder summit cambered surface (105) of inner face is 0.2 ~ 0.5mm, and its corresponding central angle number of degrees are 50 ~ 65 °; The outer circular bead surface (113) of inner face be taper seat, outer convex globoidal or inner concave arc surface, and the outer circular bead surface (113) of inner face is when being cambered surface, and the inner face outward radius of circular bead surface (113) is 4 ~ 20mm, and its corresponding central angle number of degrees are 60 ~ 85 °; The line at outer secondary sealing area (99) two ends of inner face and the axis angulation of oil well pipe are 10 ~ 20 °; The line at outer the 3rd sealing surface (101) two ends of inner face and the axis angulation of oil well pipe are 5 ~ 15 °; The line at outer circular bead surface (113) two ends of inner face and the axis angulation of oil well pipe are 60 ~ 85 °.

9. as claimed in claim 1 without the wide wedge type thread compound of the multi-sealed change tooth of box cupling well casing structure, it is characterized in that: on the longitudinal cross-section of oil well pipe, the right seal section of described internal thread (1.6) comprises circular bead surface (90) in primary sealing area (74) in the inner face, the interior secondary sealing area (76) of inner face, interior the 3rd sealing surface (78) of inner face, the interior shoulder summit cambered surface (82) of inner face and the inner face; The left plane of tooth top (56) that is positioned at the rightmost side joins with inner face primary sealing area (74), primary sealing area (74) joins with the interior secondary sealing area (76) of inner face in the inner face, secondary sealing area (76) joins with interior the 3rd sealing surface (78) of inner face in the inner face, the 3rd sealing surface (78) and interior shoulder summit cambered surface (82) rounding off of inner face in the inner face, shoulder summit cambered surface (82) and interior circular bead surface (90) rounding off of inner face in the inner face, circular bead surface (90) joins by fillet with the inner hole wall of oil well pipe in the inner face; And the length of primary sealing area (74) is 3.0 ~ 6.0mm in the described inner face, and its tapering is greater than the tapering of body internal thread segment (1.2); The length of secondary sealing area (76) is 3.0 ~ 6.0mm in the inner face, and secondary sealing area (76) be taper seat, outer convex globoidal or inner concave arc surface in the inner face, and the interior secondary sealing area (76) of inner face is when being cambered surface, and its corresponding central angle number of degrees are 12 ~ 18 °; The length of the 3rd sealing surface (78) is 4.0 ~ 8.0mm in the inner face, and the 3rd sealing surface (78) be taper seat, outer convex globoidal or inner concave arc surface in the inner face, and interior the 3rd sealing surface (78) of inner face is when being cambered surface, and its corresponding central angle number of degrees are 3 ~ 9 °; The radius of shoulder summit cambered surface (82) is 0.2 ~ 0.5mm in the inner face, and its corresponding central angle number of degrees are 50 ~ 65 °; Circular bead surface (90) be taper seat, outer convex globoidal or inner concave arc surface in the inner face, and the interior circular bead surface (90) of inner face is when being cambered surface, and its radius is 4 ~ 20mm, and its corresponding central angle number of degrees are 60 ~ 85 °; The line at secondary sealing area (76) two ends and the axis angulation of oil well pipe are 10 ~ 20 ° in the inner face; The line at the 3rd sealing surface (78) two ends and the axis angulation of oil well pipe are 5 ~ 15 ° in the inner face; The line at circular bead surface (90) two ends and the axis angulation of oil well pipe are 60 ~ 85 ° in the inner face.

10. as claimed in claim 1 without the wide wedge type thread compound of the multi-sealed change tooth of box cupling well casing structure, it is characterized in that: the number of threads of described body internal thread segment (1.2) is 12 ~ 30; The first buckle teeth well width of body internal thread segment (1.2) is 1.8 ~ 3.2mm; The spigot surface pitch of body internal thread segment (1.2) is 3.96 ~ 9.60; The bearing surface pitch of body internal thread segment (1.2) equals: (the internal thread total length deducts 2 times of first buckle teeth groove widths)/(always detain number and deduct 1); The first buckle teeth of body internal thread segment (1.2) is wide to be: spigot surface pitch deducts first buckle teeth groove width; The tooth depth of body internal thread segment (1.2) is: 1.5 ~ 2.5mm.

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