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Title:
PIPE FOR THE TECHNICAL CASING OF A GEOLOGICAL PROSPECTING DRILLING RIG
Document Type and Number:
WIPO Patent Application WO/2011/044691
Kind Code:
A1
Abstract:
Embodiments of this invention relates to the field of geological prospecting, in particular to hermetic tapered threaded connections for tubular structures (sections) in the construction of drilling strings and/or casing strings used for drilling geological prospecting wells to investigate the subsurface earth's crust to determine the presence of useful minerals.

Inventors:
NIZIENKO, Yuri Konstantinovich (Sirenevt Bulevar, 5-124Troits, Moskovskaya obl. 0, 14219, RU)
BELILOVSKIY, Victor (99 Avenue Road, Suite 708Toronto, Ontario M5R 2G5, CA)
Application Number:
CA2010/001631
Publication Date:
April 21, 2011
Filing Date:
October 12, 2010
Export Citation:
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Assignee:
KAI SERVICES INC. (5140 Yonge Street, Suite 2250Toronto, Ontario M2N 2L7, CA)
NIZIENKO, Yuri Konstantinovich (Sirenevt Bulevar, 5-124Troits, Moskovskaya obl. 0, 14219, RU)
BELILOVSKIY, Victor (99 Avenue Road, Suite 708Toronto, Ontario M5R 2G5, CA)
International Classes:
E21B17/042; E21B17/08; F16L15/06; F16L15/08
Foreign References:
US4662659A
US5788401A
US4958862A
US4946201A
US4688832A
Attorney, Agent or Firm:
BERESKIN & PARR LLP / S.E.N.C.R.L., S.R.L. (40 King Sreet West, Suite 4000Toronto, Ontario M5H 3Y2, CA)
Download PDF:
Claims:
CLAIMS:

1. A Pipe for the technical casing of a geological prospecting drilling rig, equipped with hermetic threaded connecting devices positioned at its opposite ends for connecting adjoining pipes of the drilling or casing string, having matching connecting devices; herewith the hermetic connection devices include: a tapered tool joint pin positioned at one end of the pipe with a threaded part positioned in the central region of its outer tapered surface, by an axially directed projection with a smooth sealing outer surface, which is physically a continuation of the threaded part and is formed within the diameter of the valleys on the side of the smaller diameter thread, and also with an inclined bearing sealing shoulder, radially extending in the direction of the periphery with respect to the threaded part on the side of its larger diameter and axially distanced with respect to the threaded part by the magnitude of the axially directed section with a smooth sealing outer surface, being structurally a continuation of the threaded part and formed within the diameter of the peaks of said thread in this zone; positioned at the other end of the a tool joint box positioned at the other end of the pipe, being structurally organized to allow the possibility of screwing into it the matching tapered tool joint pin of the adjoining pipe to form a tapered threaded interlocking connection in the central region of its inner tapered surface, which on the side of the box thread with the smaller diameter is transformed into an axially directed section with a smooth sealing inner surface formed within the diameter of the peaks of the thread in this zone, which is bounded by a shoulder radially directed towards the axis of the pipe, and on the side of the larger diameter thread said tapered surface is transformed into an axially directed section with a smooth sealing inner surface formed within the diameter of the valleys of the thread in this zone and bounded by the inclined bearing end surface of the box, designed to engage with the matching surface of the inclined bearing shoulder of the matching tapered tool joint pin of the adjoining pipe at an angle to the axis of connection with the formation of a tapered surface of interface with a vertex turned in the axially opposite direction to the drilling; the geometric parameters of the sealing surfaces of the tapered tool joint pin and of the tool joint box are chosen from the conditions which will provide, in the engagements with the corresponding sealing surfaces of the tool joint box and the tapered tool joint pin, respectively, of the adjoining connecting pipes of the casing, an inter-metallic sealing interaction in the process of tightening (assembly) of the corresponding connection; the profiles of the tapered thread in the corresponding sections of the tapered tool joint pin and tool joint box are realized as similar shapes in the form of trapezoids with sides of unequal length, principally, with rounded vertices, while in the operational state of the connection contact is carried out along the relatively steep lateral bearing surfaces of the thread, oriented at a negative angle with respect to the perpendicular to the axis of the pipe, the gently sloping lateral surfaces are spatially positioned with a gap with respect to the analogous matching surfaces of the adjoining connecting pipes in the casing; and the height, at least, of the part of the profile elements of the thread, that is, the peaks and valleys, of the tapered tool joint pin exceeds the height of the matching, in the operational state of the pipe connection, of the profile elements of the thread of tool joint box of the adjoining pipe; wherein: in the body of the axially directed section with the smooth sealing outer surface, which [section] is positioned on the side of the larger diameter thread of the tapered tool joint pin, as well as in the body of the axially directed section with a smooth sealing inner surface, which [section] is positioned on the side of the smaller diameter thread of the tool joint box, are executed circular profiled grooves, which are functionally a means of changing the direction of load on the corresponding thread, while the maximum depth of said grooves, principally, exceeds the height of the profile of the corresponding thread.

2. The pipe according to claim 1 , wherein, at least, part of the area of sealing surfaces of the tapered tool joint pin and the tool joint box is formed in the shape of elements of conical shape, principally, with a different degree of taper.

3. The pipe according to claim 1 , wherein the sealing surfaces of the tapered tool joint pin and the tool joint box are executed in a cylindrical form.

4. The pipe according to claim 1 , wherein the sealing surfaces of the tapered tool joint pin and/or the tool joint box are executed with an anti-friction and/or corrosion-resistant coating from a material with a modulus of elasticity not exceeding, principally, the lower modulus of elasticity of the material of the pipe.

5. A Pipe for the technical casing of geological prospecting drilling rig, equipped with hermetic threaded connecting devices positioned at its opposite ends for connecting adjoining pipes of the drilling or casing string, having matching connecting devices; herewith the hermetic connection devices include: a tapered tool joint pin positioned at one end of the pipe with a threaded part positioned in the central region of its outer tapered surface, by an axially directed projection with a smooth sealing outer surface, which is physically a continuation of the threaded part and is formed within the diameter of the valleys on the side of the smaller diameter thread, and also with an inclined bearing sealing shoulder, radially extending in the direction of the periphery with respect to the threaded part on the side of its larger diameter and axially distanced with respect to the threaded part by the magnitude of the axially directed section with a smooth sealing outer surface, which is physically a continuation of the threaded part and is formed within the diameter of the peaks of said thread in this zone; a tool joint box positioned on the other end of the pipe being structurally organized to allow the possibility of screwing into it the matching tapered tool joint pin of the adjoining pipe to form a tapered threaded interlocking connection in the central region of its inner tapered surface, which on the side of the box thread with the smaller diameter is transformed into an axially directed section with a smooth sealing inner surface formed within the diameter of the peaks of the thread in this zone, which is bounded by a shoulder radially directed towards the axis of the pipe, and on the side of the larger diameter thread said tapered surface is transformed into an axially directed section with a smooth sealing inner surface formed within the diameter of the valleys of the thread in this zone and bounded by the inclined bearing end surface of the box, designed to engage with the matching surface of the inclined bearing shoulder of the matching tapered tool joint pin of the adjoining pipe at an angle to the axis of connection with the formation of a tapered surface of interface with a vertex turned in an axially opposite direction to the drilling; the geometrical parameters of the sealing surfaces of the tapered tool joint pin and tool joint box are selected from conditions ensuring, in engagements with the matching sealing surfaces of the tool joint box and the tapered tool joint pin, respectively, of the adjoining connecting pipes of the casing, an inter-metallic sealing interaction in the process of tightening (assembly) of the corresponding connection; the profiles of the tapered thread in the corresponding sections of the tapered tool joint pin and tool joint box are realized as similar shapes in the form of trapezoids with sides of unequal length, principally, with rounded vertices, while in the operational state of the connection contact is carried out along the relatively steep lateral bearing surfaces of the thread, oriented at a negative angle with respect to the perpendicular to the axis of the pipe, while the gently sloping lateral interlocking surfaces are spatially distanced with a gap relative to the analogous matching surfaces of the adjoining connecting pipes in the casing, wherein: the height, at least, of part of the profile elements, that is, the peaks and valleys, of the thread of the tool joint box exceeds the height of the matching, in the operational state of the connection, profile elements of the thread of the tapered tool joint pin of the adjoining pipe.

6. The pipe according to claim 5, wherein in the body of the axially directed section with a smooth outer surface sealing, which [section] is positioned on the side of the larger diameter thread of the tapered tool joint pin, as well as in the body of the axially directed section with a smooth sealing inner surface, which [section] is positioned on the side of the smaller diameter thread of the tool joint box, are executed circular profiled grooves, which are functionally a means of changing the direction of load on the corresponding thread, while the maximum depth of said grooves, principally, exceeds the height of the profile of the corresponding thread.

7. The pipe according to claim 5, wherein, at least, part of the area of the sealing surfaces of the tapered tool joint pin and tool joint box is formed in the shape of elements of conical form.

8. The pipe according to claim 5, wherein the sealing surfaces of the tapered tool joint pin and the tool joint box are executed in a cylindrical form.

9. The pipe according to claim 5, wherein the sealing surfaces of the tapered tool joint pin and/or the tool joint box are executed with an anti-friction and/or corrosion-resistant coating from a material with a modulus of elasticity not exceeding, principally, smaller than, the modulus of elasticity of the material of the pipe.

10. A Pipe for the technical casing of geological prospecting drilling rig, equipped with hermetic threaded connecting devices positioned at its opposite ends for connecting adjoining pipes of the drilling or casing string, having matching connecting devices; herewith the hermetic connection devices include: a tapered tool joint pin positioned at one end of the pipe with a threaded part positioned in the central region of its outer tapered surface, by an axially directed projection with a bearing end and a smooth sealing outer surface, which is physically a continuation of the threaded part and is formed within the diameter of the valleys on the side of the smaller diameter thread, and also with a shoulder radially extending in the direction of the periphery with respect to the threaded part on the side of its larger diameter and axially distanced with respect to the threaded part by the magnitude of the axially directed section with a smooth sealing outer surface, which is structurally a continuation of the threaded section and formed within the diameter of the peaks of said thread in this zone; a tool joint box positioned at the other end of the pipe, being structurally organized to allow the possibility of screwing into it the matching tapered tool joint pin of the adjoining pipe to form a tapered threaded interlocking connection in the central region of its inner tapered surface, which on the side of the box thread with the smaller diameter is transformed into an axially directed section with a smooth sealing inner surface formed within the diameter of the peaks of the thread in this zone, which is bounded by a bearing shoulder radially directed towards the axis of the pipe, and on the side of the larger diameter thread said tapered surface is transformed into an axially directed section with a smooth sealing inner surface formed within the diameter of the valleys of the thread in this zone, bounded by the end surface, spatially separated in the operational state from the opposite surface of the shoulder of the matching tapered tool joint pin of the adjoining pipe by means of a gap; the geometrical parameters of the sealing surfaces of the tapered tool joint pin and tool joint box are chosen from the conditions for providing, in the engagements with the matching sealing surfaces of the tool joint box and tapered tool joint pin, respectively, of the adjoining connecting pipes of the casing, an inter-metallic sealing interaction in the process of tightening (assembly) of the corresponding connection; the profiles of the tapered thread in the corresponding sections of the tapered tool joint pin and tool joint box are realized as similar shapes in the form of trapezoids with sides of unequal length, principally, with rounded vertices, while in the operational state of the connection contact is carried out along the relatively steep lateral bearing surfaces of the thread, oriented at a negative angle with respect to the perpendicular to the axis of the pipe, while the gently sloping lateral interlocking surfaces are spatially distanced with a gap relative to the analogous matching surfaces of the adjoining connecting pipes in the casing; herewith, the height, at least, of part of the profile elements of the thread that is, the peaks and valleys, of the tapered tool joint pin exceeds the height of the matching, in the operational state of the connection, of the matching profile elements of the thread of the tool joint box of the adjoining pipe; wherein in the body of the axially directed section with a smooth sealing outer surface, which [section] is positioned on the side of the larger diameter thread of the tapered tool joint pin, as well as in the body of the axially directed section with a smooth sealing inner surface, which [section] is positioned on the side of the smaller diameter thread of the tool joint box, are executed circular profiled grooves, which are functionally a means of changing the direction of load on the corresponding thread, while the maximum depth of said grooves, principally, exceeds the height profile of the corresponding thread; herewith, the surfaces of the bearing shoulder of the box and the bearing end of the tapered tool joint pin, functionally serving as sealing surfaces in conjunction with the matching surfaces of the corresponding connecting elements of the adjoining pipes of the casing, spatially oriented at an angle to the axis of said pipes to form a tapered surface of engagement with the vertex, turned in an axially opposite direction to the drilling of the well.

1 1. The pipe according to claim 10, wherein, at least, part of the area of the sealing surfaces of the tapered tool joint pin and tool joint box is formed in the shape of elements of conical form.

12. The pipe according to claim 10, wherein the sealing surfaces of the tapered tool joint pin and the tool joint box are executed in a cylindrical form.

13. The pipe according to claim 10, wherein the sealing surfaces of the tapered tool joint pin and/or the tool joint box are executed with an anti-friction and/or corrosion-resistant coating from a material with a modulus of elasticity not exceeding, principally, the lower modulus of elasticity of the material of the pipe.

14. A Pipe for the technical casing of geological prospecting drilling rig, equipped with hermetic threaded connecting devices positioned at its opposite ends for connecting adjoining pipes of the drilling or casing string, having matching connecting devices; herewith the hermetic connection devices include: a tapered tool joint pin positioned at one end of the pipe with a threaded part positioned in the central region of its outer tapered surface, by an axially directed projection with a bearing end and a smooth sealing outer surface, which is physically a continuation of the threaded part and is formed within the diameter of the valleys of the smaller diameter thread, and also with a shoulder radially extending in the direction of the periphery with respect to the threaded part on the side of its larger diameter and axially distanced with respect to the threaded part by the magnitude of the axially directed section with a smooth sealing outer surface, being structurally a continuation of the threaded part and formed within the diameter of the peaks of said thread in this zone; positioned at the other end of the a tool joint box positioned at the other end of the pipe, being structurally organized to allow the possibility of screwing into it the matching tapered tool joint pin of the adjoining pipe to form a tapered threaded interlocking connection in the central region of its inner tapered surface, which on the side of the box thread with the smaller diameter is transformed into an axially directed section with a smooth sealing inner surface, formed within the diameter of the peaks of the thread in this zone, which is bounded by a bearing shoulder radially directed towards the axis of the connection, and on the side of the larger diameter thread said tapered surface is transformed into an axially directed section with a smooth sealing inner surface formed within the diameter of the valleys of the thread in this zone, bounded by an end surface, spatially separated in the operational state from the opposite surface of the shoulder of the matching tapered tool joint pin of the adjoining pipe by means of a gap; the geometrical parameters of the sealing surfaces of the tapered tool joint pin and tool joint box are selected from conditions ensuring, in engagements with the matching sealing surfaces of the tool joint box and the tapered tool joint pin, respectively, of the adjoining connecting pipes of the casing, an inter-metallic sealing interaction in the process of tightening (assembly) of the corresponding connection; the profiles of the tapered thread in the corresponding sections of the tapered tool joint pin and tool joint box are realized as similar shapes in the form of trapezoids with sides of unequal length, principally, with rounded vertices, while contact, in the operational state of the pipe connection, is carried out along the relatively steep lateral bearing surfaces of the thread oriented at a negative angle with respect to the perpendicular to the axis of the pipe, while the gently sloping lateral interlocking surfaces are spatially distanced with a gap relative to the analogous matching surfaces of the adjoining connecting pipes in the casing, wherein: the height, at least, of part of the profile elements, that is, the peaks and valleys, of the thread of the tool joint box exceeds the height of the matching, in the operational state of the pipe connection, profile elements of the thread of the tapered tool joint pin of the adjoining connecting pipe; herewith, the surfaces of the bearing shoulder of the box and the bearing end of the tapered tool joint pin, functionally serving as sealing surfaces in conjunction with the matching surfaces of the corresponding connecting elements of the adjoining pipes of the casing, spatially oriented at an angle to the axis of connection with the formation of a tapered surface of interface with a vertex turned in an axially opposite direction to the drilling of the well.

15. The pipe according to claim 14, wherein in the body of the axially directed section with a smooth sealing outer surface, which [section] is positioned on the side of the larger diameter thread of the tapered tool joint pin, as well as in the body of the axially directed section with a smooth sealing inner surface, which [section] is positioned on the side of the smaller diameter thread of the tool joint box, are executed circular profiled grooves, which are functionally a means of changing the direction of load on the corresponding thread, while the maximum depth of said grooves, principally, exceeds the height of the profile of this thread.

16. The pipe according to claim 14, wherein, at least, part of the area of the sealing surfaces of the tapered tool joint pin and tool joint box is formed in the shape of elements of conical form.

17. The pipe according to claim 14, wherein the sealing surfaces of the tapered tool joint pin and the tool joint box are executed in a cylindrical form.

18. The pipe according to claim 14, wherein the sealing surfaces of the tapered tool joint pin and/or the tool joint box are executed with an anti-friction and/or corrosion-resistant coating from a material with a modulus of elasticity not exceeding, principally, the lower modulus of elasticity of the material of the pipe.

Description:
TITLE: PIPE FOR THE TECHNICAL CASING OF A GEOLOGICAL

PROSPECTING DRILLING RIG

FIELD

[0001] Embodiments of this invention relate to the field of geological prospecting, in particular to hermetic tapered threaded connections for tubular structures (sections) in the construction of drilling strings and/or casing strings used for drilling geological prospecting wells to investigate the subsurface earth's crust to determine the presence of useful minerals.

[0002] More specifically, the embodiments of the invention relate to drilling or casing pipes (used with tapered threaded connections), containing a means of changing load direction on the thread, as well as a number of independent seals that are sensitive to external stimuli (pressure), are spaced in the axial direction relative to the seal, which is formed by direct mutual engagement of the structural profile elements of the thread, with the aim of insulating the thread from the effects of the fluid medium both inside the pipe channel, as well as from the outer surface of the connected tubular structures.

INTRODUCTION

[0003] The task of sealing tapered threaded connections can be reduced essentially to their compaction by some means or other, that is, it consists of the task of closing off along the cross-section in any area of the threaded connection the apertures of the four channels of leakage, namely:

[0004] - the channel between the spiral of peaks of the box thread and the spiral of valleys of the pipe (pin) thread; [0005] - the channel between the spiral of valleys of the box thread and the spiral of peaks of the pipe (pin) thread;

[0006] - the channel between the spirals of the lateral frontal surfaces of the threads of the box and the pipe (pin); [0007] - the channel between the spirals of the lateral rear surfaces of the threads of the box and the pipe (pin).

[0008] From the prior art is known a pipe for the technical casing of a geological prospecting drilling rig, equipped with hermetic connecting devices positioned at opposite ends for the connection of adjoining pipes in the drilling or casing string, having matching connecting devices; herewith, the hermetic connecting means include:

[0009] - a tapered tool joint pin positioned at one end of the pipe with a threaded part positioned in the central region of its outer tapered surface, by an axially directed projection with a smooth sealing outer surface, which is physically a continuation of the threaded part and is formed within the diameter of the valleys on the side of the smaller diameter thread, and also with an inclined bearing sealing shoulder, radially extending in the direction of the periphery with respect to the threaded part on the side of its larger diameter and axially distanced with respect to the threaded part by the magnitude of the axially directed section with a smooth sealing outer surface, which is physically a continuation of the threaded part and is formed within the diameter of the peaks of said thread in this zone;

[0010] - a tool joint box positioned at the other end of the pipe, being structurally organized to allow the possibility of screwing into it the matching tapered tool joint pin of the adjoining pipe to form a tapered threaded interlocking connection in the central region of its inner tapered surface, which on the side of the box thread with the smaller diameter is transformed into an axially directed section with a smooth sealing inner surface formed within the diameter of the peaks of the thread in this zone, which is bounded by a shoulder radially directed towards the axis of the pipe, and on the side of the larger diameter thread said tapered surface is transformed into an axially directed section with a smooth sealing inner surface formed within the diameter of the valleys of the thread in this zone and bounded by the inclined bearing end surface of the box, designed to engage with the matching surface of the inclined bearing shoulder of the matching tapered tool joint pin of the adjoining pipe at an angle to the axis of connection with the formation of a tapered surface of interface with a vertex turned in the axially opposite direction to the direction of drilling; [001 1] - the geometric parameters of the sealing surfaces of the tapered tool joint pin and of the tool joint box are chosen from the conditions which will provide, in the engagements with the corresponding sealing surfaces of the tool joint box and the tapered tool joint pin, respectively, of the adjoining connecting pipes of the casing, an inter-metallic sealing interaction in the process of tightening the connection;

[0012] - the profiles of the tapered thread in the corresponding sections of the tapered tool joint pin and tool joint box are realized as similar shapes in the form of trapezoids with sides of unequal length, principally, with rounded vertices, while in the operational state of the connection contact is carried out along the relatively steep lateral bearing surfaces of the thread, oriented at a negative angle with respect to the perpendicular to the axis of the pipe, the gently sloping lateral fixed surfaces are spatially distanced with a gap relative to the analogous matching surfaces of the adjoining connecting pipes in the casing; [0013] - while the height, at least, of the part of the profile elements of the thread, that is, the peaks and valleys, of the tapered tool joint pin exceeds the height of the matching, in the operational state of the pipe connection, profile elements in the thread of the tool joint box of the adjoining pipe (US, No. 5,788,401 , 1998).

[0014] It should be added to the disadvantages of this known art solution that there is inadequate hermeticity of the connection formed by adjoining pipes in connection with the implementation of sealing circular structures (smooth sealing surfaces) of cylindrical form with inter-metallic contact directly on the metal of the connecting (adjoining) pipe elements, which (in performing repeated assembly and disassembly of a connection with a tight fit, that is, an interference fit, using the known pipes) leads to the appearance of abrasions on the engaging sealing surfaces of adjoining pipes and, as a consequence, a loss of hermeticity and penetration of fluid into the zone of threaded engagement, and this reduces the working life of the threaded connection as a whole (due to progressive corrosion), as well as its reliability in relation to acceptance of workload.

[0015] Another drawback of the reviewed known art solution is the relatively uneven distribution of load between the structural profile elements of the thread in the operational state of the pipe with relative misalignments of adjoining pipes in the process of employment, due to the absence of specific structural means in the area of connection (thread) to ensure that (under certain operating conditions, that is, with the formation of misalignments and bending moments in the zone of the thread) there is a redistribution of load between the turns of the thread. This also reduces the reliability and lifetime of the connection as a whole.

SUMMARY

[0016] The claimed technical solution was based on the challenge of improving the lifetime of the pipe in its operational condition and the reliability of the connection to adjoining pipes, while ensuring optimal conditions for performing repeated assembly and disassembly without damaging the integrity (quality) of the engaging sealing surfaces of adjoining pipes in the operational state.

[0017] In this way, the technical result is an increase in the hermeticity of the tapered threaded connection through the use of the claimed pipe and the provision of even distribution of workload over all the turns of the thread in the process of employment in order to improve the durability and reliability of the combined technological system as a whole.

[0018] This technical result (according to the first embodiment of the invention) is achieved by there being in the pipe for the technical casing of a geological prospecting drilling rig, equipped with hermetic threaded connecting devices, positioned at opposite ends, for the connection of adjoining pipes of the drilling or casing string, having matching connecting devices; herewith, the hermetic connecting means include:

[0019] - a tapered tool joint pin positioned at one end of the pipe with a threaded part positioned in the central region of its outer tapered surface, by an axially directed projection with a smooth sealing outer surface, which is physically a continuation of the threaded part and is formed within the diameter of the valleys on the side of the smaller diameter thread, and also with an inclined bearing sealing shoulder, radially extending in the direction of the periphery with respect to the threaded part on the side of its larger diameter and axially distanced with respect to the threaded part by the magnitude of the axially directed section with a smooth sealing outer surface, which is structurally a continuation of the threaded part and formed within the diameter of the peaks of said thread in this zone; and [0020] - a tool joint box positioned at the other end of the pipe, being structurally organized to allow the possibility of screwing into it the matching tapered tool joint pin of the adjoining pipe to form a tapered threaded interlocking connection in the central region of its inner tapered surface, which on the side of the box thread with the smaller diameter is transformed into an axially directed section with a smooth sealing inner surface formed within the diameter of the peaks of the thread in this zone, which is bounded by a shoulder radially directed towards the axis of the pipe, and on the side of the larger diameter thread said tapered surface is transformed into an axially directed section with a smooth sealing inner surface formed within the diameter of the valleys of the thread in this zone and bounded by the inclined bearing end surface of the box, designed to engage with the matching surface of the inclined bearing shoulder of the matching tapered tool joint pin of the adjoining pipe at an angle to the axis of connection with the formation of a tapered surface of interface with a vertex turned in the axially opposite direction to the direction of drilling. [0021] In some examples, the geometric parameters of the sealing surfaces of the tapered tool joint pin and of the tool joint box are chosen from the conditions which will provide, in the engagements with the corresponding sealing surfaces of the tool joint box and the tapered tool joint pin, respectively, of the adjoining connecting pipes of the casing, an inter-metallic sealing interaction in the process of tightening the connection.

[0022] In some examples, the profiles of the tapered thread in the corresponding sections of the tapered tool joint pin and tool joint box are realized as similar shapes in the form of trapezoids with sides of unequal length, principally, with rounded vertices, while in the operational state of the connection contact is carried out along the relatively steep lateral bearing surfaces of the thread, oriented at a negative angle with respect to the perpendicular to the axis of the pipe, the gently sloping lateral fixed surfaces are spatially distanced with a gap relative to the analogous matching surfaces of the adjoining connecting pipes in the casing.

[0023] In some examples, while the height, at least, of the part of the profile elements of the thread, that is, the peaks and valleys, of the tapered tool joint pin exceeds the height of the matching, in the operational state of the pipe connection, profile elements of the thread of the tool joint box of the adjoining pipe.

[0024] In some examples, in the body of the axially directed section with a smooth sealing outer surface, which [section] is positioned on the side of the larger diameter thread of the tapered tool joint pin, as well as in the body of the axially directed section with a smooth sealing inner surface, which [section] is positioned on the side of the smaller diameter thread of the tool joint box, are executed circular profiled grooves, which are functionally a means of changing the direction of load on the corresponding thread, while the maximum depth of said grooves, principally, exceeds the height of the profile of the corresponding thread. [0025] It is reasonable that, at least, part of the area of the sealing surfaces of the tapered tool joint pin and the tool joint box be formed in the shape of elements of conical form, principally, with a different degree of taper.

[0026] It is admissible for the sealing surfaces of the tapered tool joint pin and the tool joint box to be executed in a cylindrical form.

[0027] It is practicable for the sealing surfaces of the tapered tool joint pin and/or the tool joint box to be executed with an anti-friction and/or corrosion-resistant coating composed of a material with a modulus of elasticity not exceeding, principally, the lower modulus of elasticity of the material of the pipe.

[0028] The delivered technical result (according to the second embodiment of the invention) is achieved by there being in the pipe for the technical casing of a geological prospecting drilling rig, equipped with hermetic threaded connecting devices, positioned at opposite ends, for the connection of adjoining pipes of the drilling or casing string, having matching connecting devices; herewith, the hermetic connecting means include:

[0029] - a tapered tool joint pin, positioned at one end of the pipe, with a threaded part positioned in the central region of its outer tapered surface, by an axially directed projection with a smooth sealing outer surface, which is physically a continuation of the threaded part and is formed within the diameter of the valleys on the side of the smaller diameter thread, and also with an inclined bearing sealing shoulder, radially extending in the direction of the periphery with respect to the threaded part on the side of its larger diameter and axially distanced with respect to the threaded part by the magnitude of the axially directed section with a smooth sealing outer surface, which is structurally an extension of the threaded part and formed within the diameter of the peaks of said thread in this zone;

[0030] - a tool joint box positioned at the other end of the pipe, being structurally organized to allow the possibility of screwing into it the matching tapered tool joint pin of the adjoining pipe to form a tapered threaded interlocking connection in the central region of its inner tapered surface, which on the side of the box thread with the smaller diameter is transformed into an axially directed section with a smooth sealing inner surface formed within the diameter of the peaks of the thread in this zone, which is bounded by a shoulder radially directed towards the axis of the pipe, and on the side of the larger diameter thread said tapered surface is transformed into an axially directed section with a smooth sealing inner surface formed within the diameter of the valleys of the thread in this zone and bounded by the inclined bearing end surface of the box, designed to engage with the matching surface of the inclined bearing shoulder of the matching tapered tool joint pin of the adjoining pipe at an angle to the axis of connection with the formation of a tapered surface of interface with a vertex turned in the axially opposite direction to the direction of drilling.

[0031 ] In some examples, the geometric parameters of the sealing surfaces of the tapered tool joint pin and of the tool joint box are chosen from the conditions which will provide, in the engagements with the corresponding sealing surfaces of the tool joint box and the tapered tool joint pin, respectively, of the adjoining connecting pipes of the casing, an inter-metallic sealing interaction in the process of tightening the connection. [0032] In some examples, the profiles of the tapered thread in the corresponding sections of the tapered tool joint pin and tool joint box are realized as similar shapes in the form of trapezoids with sides of unequal length, principally, with rounded vertices, while in the operational state of the connection contact is carried out along the relatively steep lateral bearing surfaces of the thread, oriented at a negative angle with respect to the perpendicular to the axis of the pipe, while the gently sloping lateral fixed surfaces are spatially distanced with a gap relative to the analogous matching surfaces of the adjoining connecting pipes in the casing.

[0033] In some examples, the height, at least, of part of the profile elements, that is, the peaks and valleys, of the thread of the tool joint box exceeds the height of the matching, in the operational state of the connection, profile elements of the thread of the tapered tool joint pin of the adjoining pipe.

[0034] Optionally, in the body of the axially directed section with a smooth sealing outer surface, which [section] is positioned on the side of the larger diameter thread of the tapered tool joint pin, as well as in the body of the axially directed section with a smooth sealing inner surface, which [section] is positioned on the side of the smaller diameter thread of the tool joint box, are executed circular profile grooves, which are functionally a means of changing the direction of load on the corresponding thread, while the maximum depth of said grooves, principally, should exceed the height of the profile of the corresponding thread.

[0035] It is reasonable that, at least, part of the area of the sealing surfaces of the tapered tool joint pin and the tool joint box be formed in the shape of elements of conical form. [0036] It is admissible for the sealing surfaces of the tapered tool joint pin and the tool joint box to be executed in a cylindrical form.

[0037] It is practicable for the sealing surfaces of the tapered tool joint pin and/or the tool joint box to be executed with an anti-friction and/or corrosion-resistant coating composed of a material with a modulus of elasticity not exceeding, principally, smaller than, the modulus of elasticity of the material of the pipe.

[0038] The delivered technical result (according to the third embodiment of the invention) is achieved by there being in the pipe for the technical casing of a geological prospecting drilling rig, equipped with hermetic threaded connecting devices, positioned at opposite ends, for the connection of adjoining pipes of the drilling or casing string, having matching connecting devices; herewith, the hermetic connecting means include:

[0039] - a tapered tool joint pin positioned at one end of the pipe with a threaded part positioned in the central region of its outer tapered surface, by an axially directed projection with a bearing end and a smooth sealing outer surface, which is physically a continuation of the threaded part and is formed within the diameter of the valleys on the side of the smaller diameter thread, and also with a shoulder radially extending in the direction of the periphery with respect to the threaded part on the side of its larger diameter and axially distanced with respect to the threaded part by the magnitude of the axially directed section with a smooth sealing outer surface, which is structurally a continuation of the threaded part and formed within the diameter of the peaks of said thread in this zone; [0040] - a tool joint box positioned at the other end of the pipe, being structurally organized to allow the possibility of screwing into it the matching tapered tool joint pin of the adjoining pipe to form a tapered threaded interlocking connection in the central region of its inner tapered surface, which on the side of the box thread with the smaller diameter is transformed into an axially directed section with a smooth sealing inner surface formed within the diameter of the peaks of the thread in this zone, which is bounded by a bearing shoulder radially directed towards the axis of the pipe, and on the side of the larger diameter thread said tapered surface is transformed into an axially directed section with a smooth sealing inner surface formed within the diameter of the valleys of the thread in this zone, bounded by the end surface, spatially separated in the operational state from the opposite surface of the shoulder of the matching tapered tool joint pin of the adjoining pipe by means of a gap.

[0041] In some examples, the geometric parameters of the sealing surfaces of the tapered tool joint pin and of the tool joint box are chosen from the conditions which will provide, in the engagements with the corresponding sealing surfaces of the tool joint box and the tapered tool joint pin, respectively, of the adjoining connecting pipes of the casing, an inter-metallic sealing interaction in the process of tightening the connection. [0042] In some examples, the profiles of the tapered thread in the corresponding sections of the tapered tool joint pin and tool joint box are realized as similar shapes in the form of trapezoids with sides of unequal length, principally, with rounded vertices, while in the operational state of the connection contact is carried out along the relatively steep lateral bearing surfaces of the thread, oriented at a negative angle with respect to the perpendicular to the axis of the pipe, the gently sloping lateral fixed surfaces are spatially distanced with a gap relative to the analogous matching surfaces of the adjoining connecting pipes of the casing. [0043] In some examples, the height, at least, of part of the profile elements of the thread that is, the peaks and valleys, of the tapered tool joint pin exceeds the height of the matching, in the operational state of the connection, profile elements of the thread of the tool joint box of the adjoining pipe.

[0044] In some examples, in the body of the axially directed section with a smooth sealing outer surface, which [section] is positioned on the side of the larger diameter thread of the tapered tool joint pin, as well as in the body of the axially directed section with a smooth sealing inner surface, which [section] is positioned on the side of the smaller diameter thread of the tool joint box, are executed circular profiled grooves, which are functionally a means of changing the direction of load on the corresponding thread, while the maximum depth of said grooves, principally, exceeds the height of the profile of the corresponding thread.

[0045] In some examples, the surfaces of the bearing shoulder and the bearing end of the tapered tool joint pin, functionally serving as sealing surfaces in conjunction with the matching surfaces of the corresponding connecting elements of the adjoining pipes of the casing, spatially oriented at an angle to the axis of said pipes to form a tapered surface of engagement with the vertex, turned in an axially opposite direction to the drilling of the well. [0046] It is optional that, at least, part of the area of the sealing surfaces of the tapered tool joint pin and the tool joint box be formed in the shape of elements of conical form.

[0047] It is admissible for the sealing surfaces of the tapered tool joint pin and the tool joint box to be executed in a cylindrical form.

[0048] It is practicable for the sealing surfaces of the tapered tool joint pin and/or the tool joint box to be executed with an anti-friction and/or corrosion-resistant coating composed of a material with a modulus of elasticity not exceeding, principally, the lower modulus of elasticity of the material of the pipe.

[0049] The delivered technical result (according to the fourth embodiment of the invention) is achieved by there being in the pipe for the technical casing of a geological prospecting drilling rig, equipped with hermetic threaded connecting devices, positioned at opposite ends, for the connection of adjoining pipes of the drilling or casing string, having matching connecting devices; herewith, the hermetic connecting means include:

[0050] - a tapered tool joint pin positioned at one end of the pipe with a threaded part positioned in the central region of its outer tapered surface, by an axially directed projection with a bearing end and a smooth sealing outer surface, which is physically a continuation of the threaded part and is formed within the diameter of the valleys of the smaller diameter thread, and also with a shoulder radially extending in the direction of the periphery with respect to the threaded part on the side of its larger diameter and axially distanced with respect to the threaded part by the magnitude of the axially directed section with a smooth sealing outer surface, which is structurally a continuation of the threaded part and formed within the diameter of the peaks of said thread in this zone; and

[0051] - a tool joint box positioned at the other end of the pipe, being structurally organized to allow the possibility of screwing into it the matching tapered tool joint pin of the adjoining pipe to form a tapered threaded interlocking connection in the central region of its inner tapered surface, which on the side of the box thread with the smaller diameter is transformed into an axially directed section with a smooth sealing inner surface, formed within the diameter of the peaks of the thread in this zone, which is bounded by a bearing shoulder radially directed towards the axis of the connection, and on the side of the larger diameter thread said tapered surface is transformed into an axially directed section with a smooth sealing inner surface formed within the diameter of the valleys of the thread in this zone, bounded by an end surface, spatially separated in the operational state from the opposite surface of the shoulder of the matching tapered tip of the tool joint pin of the adjoining pipe by means of a gap.

[0052] In some examples, the geometric parameters of the sealing surfaces of the tapered tool joint pin and of the tool joint box are chosen from the conditions which will provide, in the engagements with the corresponding sealing surfaces of the tool joint box and the tapered tool joint pin, respectively, of the adjoining connecting pipes of the casing of inter-metallic sealing interaction in the process of tightening the connection.

[0053] In some examples, the profiles of the tapered thread in the corresponding sections of the tapered tool joint pin and tool joint box are realized as similar shapes in the form of trapezoids with sides of unequal length, principally, with rounded vertices, while contact, in the operational state of the pipe connection, is carried out along the relatively steep lateral bearing surfaces of the thread oriented at a negative angle with respect to the perpendicular to the axis of the pipe, while the gently sloping lateral fixed surfaces are spatially distanced with a gap relative to the analogous matching surfaces of the adjoining connecting pipes in the casing.

[0054] In some examples, the height, at least, of part of the profile elements, that is, the peaks and valleys, of the thread of the tool joint box exceeds the height of the matching, in the operational state of the pipe connection, profile elements of the thread of the matching tapered tool joint pin of the adjoining pipe.

[0055] In some examples, the surfaces of the bearing shoulder and the bearing end of the tapered tool joint pin, functionally serving as sealing surfaces in conjunction with the matching surfaces of the corresponding connecting elements of the adjoining pipes of the casing, spatially oriented at an angle to the axis of connection with the formation of a tapered surface of interface with a vertex turned in an axially opposite direction to the drilling of the well.

[0056] It is optional that in the body of the axially directed section with a smooth sealing outer surface, which [section] is positioned on the side of the larger diameter thread of the tapered tool joint pin, as well as in the body of the axially directed section with a smooth sealing inner surface, which [section] is positioned on the side of the smaller diameter thread of the tool joint box, are executed circular profiled grooves, which are functionally a means of changing the direction of load on the corresponding thread, while the maximum depth of said grooves, principally, exceeds the height of the profile of this thread.

[0057] It is practicable that, at least, part of the area of the sealing surfaces of the tapered tool joint pin and the tool joint box be formed in the shape of elements of conical form.

[0058] It is admissible for the sealing surfaces of the tapered tool joint pin and the tool joint box to be executed in a cylindrical form.

[0059] It is reasonable for the sealing surfaces of the tapered tool joint pin and/or the tool joint box to be executed with an anti-friction and/or corrosion-resistant coating composed of a material with a modulus of elasticity not exceeding, principally, the lower modulus of elasticity of the material of the pipe. [0060] An analysis of the level of technology conducted by the applicant, including search in patent and scientific-technical information sources and the identification of sources containing information about analogues of the claimed invention, has made it possible to establish that no analogues are found characterized by features and the links between them identical to all of the essential features of the claimed technical solution, while the prototype selected from the identified analogues as the closest analogue in its array of features allowed the identification of an array of significant (relative to the technical result reviewed by the applicant) distinctive features of the claimed invention, set forth in the summary of the invention.

DRAWINGS

[0061 ] For a better understanding of the embodiments described herein and to show more clearly how they may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings which show at least one exemplary embodiment, and in which:

[0062] Figure 1 is a general view of embodiment 1 of the claimed technical solution in operational state;

[0063] Figure 2 is a detail view of point I in figure 1 (nodes of the radial and end seal, and also a means of changing the direction of the load on the threads in the form of a circular profiled groove on the upper section of the connection);

[0064] Figure 3 is a detail view of point II in figure 1 (node of the radial seal and a means of changing the direction of the load on the thread in the form of a circular profiled groove on the lower section of the connection);

[0065] Figure 4 is a detail view of point III in figure 1 (the geometry of the profile of the threaded connection of pipes in operational state);

[0066] Figure 5 is a general view of embodiment 2 of the claimed technical solution in operational state; [0067] Figure 6 is a detail view of point IV in figure 5 (nodes of the radial and end seal and also a means of changing the direction of the load on the threads in the form of a circular profiled groove on the upper section of the connection);

[0068] Figure 7 is a detail view of point V in figure 5 (node of the radial seal and a means of changing the direction of the load on the thread in the form of a circular profiled groove on the lower section of the connection);

[0069] Figure 8 is a detail view of point VI in figure 5 (the geometry of the profile of the threaded connection of pipes in operational state).

[0070] Figure 9 is a general view of the claimed technical solution for embodiment 3 in operational state;

[0071] Figure 10 is a detail view of point VII of figure 9 (nodes of the radial and end seal and also a means of changing the direction of the load on the thread in the form of a circular profiled groove on the lower section of the connection);

[0072] Figure 11 is a detail view of point VIII in figure 9 (a node of the radial seal and also a means of changing the direction of the load on the thread in the form of a circular profiled groove on the upper section of the connection);

[0073] Figure 12 is a detail view of point IX in figure 9 (the geometry of the profile of the threaded connection of pipes in operational state);

[0074] Figure 13 is a general view of the claimed technical solution for embodiment 4 in operational state;

[0075] Figure 14 is a detail view of point X in figure 13 (nodes of the radial and end seal and also a means of changing the direction of the load on the thread in the form of a circular profiled groove on the lower section of the connection);

[0076] Figure 15 is a detail view of point XI in figure 13 (a node of the radial seal and also a means of changing the direction of the load on the thread in the form of a circular profiled groove on the upper section of the connection); and

[0077] Figure 16 is a detail view of point XII of figure 13 (the geometry of the profile of the threaded connection of pipes in operational state). [0078] For simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

DESCRIPTION OF VARIOUS EMBODIMENTS

[0079] Various apparatuses or processes will be described below to provide an example of an embodiment of each claimed invention. No embodiment described below limits any claimed invention and any claimed invention may cover processes or apparatuses that are not described below. The claimed inventions are not limited to apparatuses or processes having all of the features of any one apparatus or process described below or to features common to multiple or all of the apparatuses described below. It is possible that an apparatus or process described below is not an embodiment of any claimed invention. Any invention disclosed in an apparatus or process described below that is not claimed in this document may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicants, inventors or owners do not intend to abandon, disclaim or dedicate to the public any such invention by its disclosure in this document.

[0080] In the drawings the corresponding constructional elements and structures are indicated by the following locations.

[0081] 1 - tool joint pin (tapered with a central threaded part on the outer surface). [0082] 2 - projection (of tool joint pin 1 , axially directed with smooth sealing outer surface 3).

[0083] 3 - surface (sealing, on projection 2).

[0084] 4 - shoulder (of tool joint pin 1). [0085] 5 - surface (of end shoulder 4).

[0086] 6 - section (of tool joint pin 1 , with smooth sealing outer surface

7)·

[0087] 7 - surface (sealing, of section 6).

[0088] 8 - box (interlocking with the internal threaded tapered surface in the central part).

[0089] 9 - section (of the inner surface of box 8, with a smooth sealing inner surface 10).

[0090] 10 - surface (inner sealing, of box 8 on section 9).

[0091] 1 1 - axis (longitudinal, of the tapered threaded connection or pipe).

[0092] 12 - shoulder (of box 8, interlocking on the side of the thread with the smaller diameter).

[0093] 13 - section (with smooth sealing surface 14, of the inner surface of box 8 on the side of its thread with the larger diameter).

[0094] 14 - surface (smooth sealing, of box 8 on section 13).

[0095] 15 - surface (end, of box 8, on section 13).

[0096] 16 - vertex (of tapered surface 17, interfacing with bearing end surface of tool joint pin 1 and box 8).

[0097] 17 - surface (interfacing conical, of bearing end surfaces of tool joint pin 1 and box 8).

[0098] 18 - direction (of drilling, indicated by the arrow). [0099] 19 - gap (between the mutually facing end surfaces of tool joint pin 1 and tool joint box 8).

[00100] 20 - surface (steep lateral bearing, with an incline of negative angle a to the thread of tool joint pin 1 ). [0100] 21 - surface (lateral gently sloping interlocking, of tool joint pin 1 ).

[0101] 22 - surface (steep lateral bearing, with a negative angle of slope to the thread of box 8)

[0102] 23 - surface (lateral gently sloping interlocking, of box 8). [0103] 24 - gap (between the lateral gently sloping interlocking surfaces 21 and 23 of the thread of tool joint pin 1 and box 8, respectively).

[0104] 25 - groove (circular, executed in the body of tool joint pin 1 , functionally serving as a means of changing the direction of load on the thread).

[0105] 26 - groove (circular, executed in the body of the box, functionally serving as a means of changing the direction of load on the thread).

[0106] 27 - coating (anti-friction and/or corrosion resistant).

[0107] The features of the structural-design implementation of the claimed technical solution according to the first embodiment of the invention are as follows.

[0108] It is worth noting for the disclosure of the claimed invention in any of the embodiments that for ease of understanding of the essential nature of the reviewed technical solution it is optimal that it be implemented in conjunction with matching coupling means in the corresponding adjoining pipe of the technical casing. The reason is that the tapered tool joint pin positioned at one end of the claimed pipe is structurally identical to the tool joint pin of the adjoining pipe and the tool joint box positioned at the other end of the claimed pipe is identical to the tool joint box of the corresponding adjoining pipe of the technical casing. Moreover, a number of structural features of the claimed technical solution (pipe) are optimally characterized in conjunction with the corresponding structural features of the adjoining pipe, that is, in the operational state of the pipe connection.

[0109] It should also be noted that in Fig. 1 , 5, 9 and 13 of the graphic material, the declared pipe (positioned in the centre of said figures) is shown in operational state, that is, assembled with adjoining (connecting) pipes of the technical casing. Moreover, the tool joint pin of the adjoining (connecting) pipe of the technical casing is shown in the upper part of said figures, and the box end of the opposite adjoining (connecting) pipe of the technical casing is shown in the lower part of these figures.

[01 10] Referring to Figures 1-4, in this way, the claimed pipe for the technical casing of a geological prospecting drilling rig, equipped with sealed connecting elements positioned at opposite ends for connecting adjoining pipes in the drilling or casing string, having matching connecting devices; herewith the hermetic connecting means of the declared pipe include:

[01 1 1] - a tapered tool joint pin 1 positioned at one end of the pipe with a threaded part positioned in the central region of its outer tapered surface, by axially directed projection 2 with smooth sealing outer surface 3, which is physically a continuation of the threaded part and is formed within the diameter of the valleys on the side of the smaller diameter thread, and also with an inclined bearing sealing shoulder 4 (having a sealing surface 5), radially extending towards the periphery with respect to the threaded part along its larger diameter and axially distanced with respect to the threaded part by the magnitude of axially directed section 6 with smooth sealing outer surface 7, which is physically a continuation of the threaded part and is formed within the diameter of the peaks of said thread in this zone;

[01 12] - tool joint box 9 positioned at the other end of the pipe, being structurally organized to allow the possibility of screwing into it the matching tapered tool joint pin of the adjoining pipe to form a tapered threaded interlocking connection in the central region of its inner tapered surface, which on the side of the box thread with the smaller diameter is transformed into an axially directed section 9 with a smooth sealing inner surface 10, formed within the diameter of the peaks of the thread in this zone, which (that is, section 9) is bounded by shoulder 12 radially directed toward axis 1 of the pipe (or the combination of pipes, that is, the casing as a whole), and on the side of the larger diameter thread said tapered threaded surface of the central region of box 8 is transformed into an axially directed section 13 with a smooth sealing inner surface 14, formed within the diameter of the valleys of the thread in this zone and bounded by inclined bearing end surface 15 of box 8, designed to interface with the matching surface of the inclined bearing shoulder of the matching tapered nipple tip of the adjoining pipe at an angle to the axis 1 1 of the pipe (or combination of pipes) to form a conjunction of tapered surface 17 interface with vertex 16, turned in an axially opposite direction 18 to the drilling (in the figures of the graphical material the direction is indicated by an arrow).

[01 13] Said end surface of the axially directed projection 2 of tapered nipple tip 1 of the claimed pipe and the opposite surface of the shoulder, radially directed toward axis 1 1 , of the box of the adjoining connecting pipe (in operational state) are spatially separated by an axial gap 19;

[0114] - the geometric parameters of the oppositely positioned engaging sealing surfaces 3 and 7 of the tapered tool joint pin 1 and tool joint box 8 (surfaces 10 and 13) are chosen from the conditions which will provide, in the engagements with the corresponding sealing surfaces of the tool joint box and the tapered tool joint pin, respectively, of the adjoining connecting pipes of the casing, an inter-metallic sealing interaction in the process of tightening (assembly) of the corresponding connection;

[01 15] - the profiles of the tapered thread in the corresponding sections of the tapered tool joint pin and tool joint box are realized as similar shapes in the form of trapezoids with sides of unequal length, principally, with rounded vertices, while, in the operational state of the connection (casing), contact is carried out along the relatively steep lateral bearing surfaces 20 and 22 of the thread, oriented at a negative angle a with respect to the perpendicular to the axis 1 1 of the pipe, the gently sloping lateral interlocking surfaces 21 and 23 are spatially positioned with a gap 24 with respect to the analogous matching surfaces of adjoining connecting pipes in the casing;

[01 16] - while the height, at least, of the part of the profile elements of the thread, that is, the peaks and valleys, of tapered tool joint pin 1 exceeds the height of the matching (in the operational state of the connected pipes) profile elements of the thread of the tool joint box of the adjoining pipe.

[01 17] Herewith, according to the illustrated embodiment:

[0 18] - in the body of axially directed section 6 with smooth sealing outer surface 7, positioned on the side of the thread of larger diameter of tapered tool joint pin 1 , as well as in the body of the axially directed section 9 with smooth sealing inner surface 10, positioned on the side of the thread of smaller diameter of tool joint box 8, are executed circular profiled grooves 25 and 26, respectively, which are functionally a means of changing the direction of load on the corresponding thread, while the maximum depth of said grooves 25 and 26, principally, exceeds the height of the profile of the corresponding thread.

[01 19] It is optimal that, at least, a part of the area of sealing surfaces 3 and 7 of the tapered tool joint pin 1 and tool joint box 8 (sealing surfaces 10 and 14, respectively) be formed in the shape of elements of conical form. [0120] It is acceptable for sealing surfaces 3 and 7 of the tapered tool joint pin 1 and tool joint box 8 (sealing surfaces 10 and 14, respectively) to execute a cylindrical form.

[0121] It is most reasonable that the engaging sealing surfaces 3 and 7 of the tapered tool joint pin 1 and/or tool joint box 8 (sealing surfaces 10 and 14 respectively) are executed with anti-friction and/or corrosion-resistant coating 27 of a material with a modulus of elasticity not exceeding, principally, the lower modulus of elasticity of the material of the pipe.

[0122] Referring to Figures 5-8, the features of the structural-design implementation of the claimed technical solution according to the second embodiment of the invention are essentially identical to the design features of the first embodiment described above.

[0123] Its distinctive features are found in the fact that the height at least, of part of the profile elements (that is, the peaks and valleys) of the thread of tool joint box 8 exceeds the height of the matching (in the operational state of the connection) profile elements of the thread of the tapered tool joint pin of the adjoining connecting pipe.

[0124] Referring to Figures 9-12, the features of the structural-design implementation of the claimed technical solution according to the third embodiment of the invention are essentially identical to the design features of the first variant described above.

[0125] Its distinctive features are found in the fact that:

[0126] - the end surface 15 of tool joint box 8, bounding its axially directed section 13 with smooth sealing inner surface 14 (positioned on the side of the thread with larger diameter), in the operational state is spatially separated from the opposite surface of the shoulder of the matching tapered tool joint pin of the adjoining pipe by means of gap 19, which is spatially oriented, principally, at a right angle to the axis 11 of the pipe;

[0127] - herewith the surfaces of bearing shoulder 12 of box 8 and the bearing end of the tapered nipple tip 1 (functionally serving as sealing surfaces in conjunction with the matching surfaces of the connecting elements of adjoining pipes in the casing) are spatially oriented at an angle to the axis 11 of the pipe with the formation of tapered surface 17 interfacing with the apex 16 turned in axially opposite direction 18 to the drilling of the well. [0128] Referring to Figures 13-16, the features of the structural-design implementation of the claimed technical solution according to the fourth embodiment of the invention are essentially identical to the design features of the first variant described above. [0 29] Its distinctive features are found in the fact that:

[0130] - the end surface 15 of the tool joint box 8, bounding its axially directed section 13 with smooth sealing inner surface 14 (positioned on the side of the thread of larger diameter) is spatially separated in operational state from the opposite surface of the shoulder of the matching tapered tool joint pin of the adjoining pipe by means of the gap 19, which is spatially oriented, principally, at right angles to the axis 11 of the connection;

[0131] - the surfaces of bearing shoulder 12 of box 8 and the bearing end of the tapered nipple tip 1 (functionally serving as sealing surfaces in conjunction with the matching surfaces of the connecting elements of adjoining pipes in the casing) are spatially oriented at an angle to the axis 11 of the pipe with the formation of tapered surface 17 interfacing with the apex 16, turned in axially opposite direction 18 to the drilling of the well.

[0132] - the height, at least, of part of the profile elements, that is, the peaks and valleys, of the thread of tool joint box 8 exceeds the height of the matching (in the operational state of the connection) profile elements of the thread of the tapered tool joint pin of the adjoining connecting pipe.

[0133] The characteristics specified in the claims are significant and interconnected to each other to form a stable array of required features sufficient to produce the desired technical result.

[0134] The properties regulated in the claimed technical solution as individual characteristics are widely known in the art and require no further explanation (see, for example, RU, N Q 21 17133 C1 , RU NQ 2297512 C1 , RU N° 2310058 C1 , RU Ne 2338866 C1 , US Ns 4892337 and others). [0135] However, it should be noted that the claimed array of essential features produces in the claimed technical solution a synergistic result (greater than the sum of parts).

[0136] The claimed device in operational state (the assembled casing) works in the following manner.

[0137] With a relative axial displacement of tool joint pin 1 and the tool joint box of the adjoining connecting pipe, at the beginning of the process of screwing there initially arises an interaction of the enveloping and the enveloped elements of the connection via the tapered thread, for example, as in the structure of the analogous thread of the "buttress" type. In the process of screwing there occurs a counter advancement of the sealing surfaces (both directed along the axis of the connection and also across the specified angles) of the tool joint pin 1 and the tool joint box of the adjoining pipe prior to their engagement. As a result, in the area of connection there are formed four "metal-metal" seal assemblies, one of which is a directly threaded engagement. That is, there occurs a forced engagement of the corresponding surfaces of the pipe connection being formed with the production of contact stresses, the size of which should be in the region of elastic deformation. The level of contact stresses, everything else being equal, is regulated by the size of the contact areas of the engaging sealing surfaces. The tapered end sealing (bearing) surfaces of tool joint pin 1 and the tool joint box 2 are executed in such a way that under the action of axial force on them, produced by the screwing of the threads, the transverse component of this effort is directed towards the axis 1 of the connection. This, firstly, eliminates the phenomenon of so-called "unwinding", that is, transverse deformation with an increase in the diameter of connected elements in the region of the bearing ends, which makes the connection less critical in exceeding the permissible torque and increases its reliability of use, and secondly, provides additional compression of the engaging sealing surfaces, forming radial nodes for the sealing of the connection. Thus, the claimed construction of the connection ensures the formation of conditions for optimal tightness for the elements of the radial seal and the optimal size of stresses in the sealing bearing elements, including the threaded engagement, due to the specific geometry of its engaging profile structures.

[0138] The elements of the construction of the hermetic tapered threaded connection (formed on the basis of the claimed technical solution) can be produced industrially with the use of modern materials and technologies in enterprises producing components of technical casings (both drilling and casing) for geological prospecting drilling rigs.

[0139] In this way, the above data are evidence of the implementation, in the operation of the claimed technical solution, of the following set of conditions:

[0140] - the object embodying the claimed technical solution in its implementation is designed for geological exploration work and could be implemented as a hermetic tapered threaded connection of tubular structures (sections) in the construction of drilling and casing strings, used in the investigation of the earth's crust to determine the presence of useful minerals (more specifically, the variants of the useful models relate to a tapered threaded connection with the use of the claimed pipe, which [connection] contains several independent seals, which are sensitive to external stimuli (pressure) and are spaced in the axial direction relative to the seal, formed directly by the mutual engagement of the profile elements of the thread with the aim of insulating it from the effects of fluid both inside the pipe channel, as well as outside the connected tubular structures);

[0141] - for the claimed object in the form that it is described in the claims, the possibility of its implementation is confirmed with the use of the means and methods mentioned above in the application or known in the art prior to the claimed technical solution;

[0142] - the object embodying the claimed technical solution is capable of achieving the technical result foreseen by the applicant. [0143] Consequently, the claimed object fulfils the "industrially applicable" condition of patentability under current law.

[0144] What has been described above has been intended to be illustrative of the invention and non-limiting and it will be understood by persons skilled in the art that other variants and modifications may be made without departing from the scope of the invention as defined in the claims appended hereto.