Assembly for producing a threaded connection for drilling and operating hydrocarbon wells, and resulting threaded connection

Patent metadata

Field	Value
Publication number	US-10113674-B2
Application number	US-201414905216-A
Country	US
Kind code	B2
Filing date	Jul 8, 2014
Priority date	Jul 18, 2013
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

An assembly producing a threaded connection, including first and second tubular components with an axis of revolution and each respectively including at one end at least a first continuous threaded zone following a first helix on an outer or inner circumferential surface depending on whether the threaded end is male or female in type, and configured to cooperate together upon makeup. The first threaded zones of the ends include a variable width dovetail thread profile, the ends respectively finishing in a terminal surface. At least one of the ends include a lip provided between the threaded zone and the terminal surface, the lip carrying a sealing surface configured to cooperate in a sealing interference fit with a corresponding sealing surface disposed facing the other end when the connection is in the made-up state. The lip is hollowed out by a groove adjoining the threaded zone and the sealing surface.

First claim

The invention claimed is:

1. An assembly for producing a threaded connection, comprising:
a first and a second tubular component with an axis of revolution and each respectively including at one of their ends at least a first continuous threaded zone following a first helix on an outer or inner circumferential surface of the component depending on whether the threaded end is male or female in type, and configured to cooperate together upon makeup,
the first threaded zones of the ends including a variable width dovetail thread profile viewed in longitudinal section passing through the axis, the ends respectively finishing in a terminal surface,
at least one of the ends including a lip provided between the threaded zone and the terminal surface, the lip carrying a sealing surface configured to cooperate in a sealing interference fit with a corresponding sealing surface disposed facing the other end when the connection is in the made up state,
wherein the lip is hollowed out by a groove adjoining the threaded zone and the sealing surface, the length of the groove being calculated as follows:

GL
≥

0.4
×

(

LFL

n
×
2

-

TL
-
RLP

LFL

×

(

LFL
-
SFL

)

)

GL
≤

2
×

(

LFL

n
×
2

-

TL
-
RLP

LFL

×

(

LFL
-
SFL

)

)

in which:
LFL is a value for pitch of load flanks;
SFL is a value for pitch of stabbing flanks;
TL is a threading length;
RLP is a reference position length;
n is a number of helixes in threading, wherein viewed in a longitudinal section passing through the axis of revolution, the groove includes an annular portion linked to the threaded zone via a first inclined portion and linked to the zone comprising the sealing surface via a second inclined portion, and wherein thickness of the groove is less than thickness of the lip by an amount of 0.2 to 2.5 mm.

2. An assembly for producing a threaded connection according to claim 1 , wherein values for parameters LFL, SFL, TL, RPL and n are limited as follows:
4 mm< LFL< 20 mm;
4 mm< SFL< 20 mm;
20 mm<TL<300 mm;
10 mm<RLP<150 mm;
1< n< 4.

3. An assembly for producing a threaded connection according to claim 2 , wherein values for parameters LFL, SFL, TL, RPL and n are limited as follows:
10 mm< LFL< 17 mm;
10 mm< SFL< 17 mm;
40 mm<TL<160 mm;
20 mm<RLP<80 mm;
n= 2.

4. An assembly for producing a threaded connection according to claim 1 , wherein the first threaded zones of the ends include a dovetail thread profile with a variable width and that are self-locking.

5. An assembly for producing a threaded connection according to claim 1 , wherein first threaded zones of the ends include a dovetail thread profile with a variable width such that:
LFL=SFL=P (pitch of threading).

6. An assembly for producing a threaded connection according to claim 1 , wherein the first inclined portion forms an angle α in a range of 20° to 75° with the axis of revolution of the connection.

7. An assembly for producing a threaded connection according to claim 1 , wherein the second inclined portion forms an angle β in a range of 5° to 90° with the axis of revolution of the connection.

8. An assembly for producing a threaded connection according to claim 1 , wherein the sealing surface of the lip is a domed surface with a radius in a range of 30 to 100 mm, while the corresponding sealing surface is a tapered surface the tangent to the peak half angle is in a range of 0.025 to 0.25, and a taper in a range of 5% to 50%.

9. An assembly for producing a threaded connection according to claim 1 , wherein a radial gap in a range of 0.05 to 0.5 mm is provided between crests of the male threads and roots of the female threads.

10. An assembly for producing a threaded connection according to claim 1 , wherein the threaded zone has negative stabbing flank angles in a range of 1 to 15 degrees.

11. An assembly for producing a threaded connection according to claim 1 , wherein the threaded zone has negative load flank angles in a range of 1 to 15 degrees.

12. An assembly for producing a threaded connection according to claim 1 , wherein the threaded zones of each end extend along a same taper generatrix with a slope in a range of 5% to 25%.

13. An assembly for producing a threaded connection according to claim 1 , wherein each of the ends of the tubular components comprises at least a second continuous threaded zone produced on another helix, of multi-start type.

14. A threaded connection resulting from making up an assembly in accordance with claim 1 .

Assignees

• Vallourec Oil & Gas France
• Nippon Steel & Sumitomo Metal Corp

Inventors

• Martin Pierre
• Legrand Bruno
• Moreau Regis

Classifications

• F16L15/06 Primary

  characterised by the shape of the screw-thread · CPC title

• F16L15/001

  with conical threads · CPC title

• E21B17/042 Primary

  Threaded · CPC title