Rotary shouldered connections and thread design

Patent metadata

Field	Value
Publication number	US-10145496-B2
Application number	US-201514737443-A
Country	US
Kind code	B2
Filing date	Jun 11, 2015
Priority date	Jun 13, 2014
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

A thread structure in accordance to one or more embodiments includes a thread extending helically along the cylindrical member in spaced thread turns, the thread having a crest extending between a first flank and a second flank and a root extending between the thread turns, the root having a curvature defined by a portion of an ellipse tangentially adjoining the first and second flank at respective flank transition points, the ellipse having a major axis extending parallel to the axis and a minor axis extending perpendicular to the major axis and through a root bottom.

First claim

What is claimed is:

1. A thread structure, comprising:
a cylindrical member extending along an axis;
a thread extending helically along the cylindrical member in spaced thread turns, the thread comprising:
a crest extending between a first flank and a second flank;
a root extending between the thread turns, the root having a curvature defined by a portion of an ellipse tangentially adjoining the first and second flank at respective flank transition points, the ellipse having a major axis extending parallel to the axis and a minor axis extending perpendicular to the major axis and through a root bottom;
a root semi-width at the flank transition points of about 0.050 to about 0.061 inches; and
an equivalent root radius of about 0.057 to about 0.061 inches.

2. The thread structure of claim 1 , further comprising:
a root depth of about 0.012 to about 0.020 inches.

3. The thread structure of claim 2 , wherein the root depth is about 0.013 to about 0.016 inches.

4. The thread structure of claim 1 , further comprising:
a root semi-width at the flank transition points of about 0.050 to about 0.055 inches;
an equivalent root radius of about 0.057 to about 0.061 inches; and
a root depth of about 0.012 to about 0.016 inches.

5. The thread structure of claim 4 , wherein the root depth is about 0.014 to about 0.015 inches.

6. The thread structure of claim 1 , further comprising:
a root depth of about 0.012 to about 0.020 inches;
a root semi-width at the flank transition points of about 0.050 to about 0.060 inches; and
a pitch of about three threads per inch.

7. The thread structure of claim 1 , further comprising:
a root depth of about 0.013 to about 0.016 inches;
a root semi-width at the flank transition points of about 0.050 to about 0.055 inches; and
a pitch of about three threads per inch.

8. The thread structure of claim 1 , further comprising:
a root semi-width at the flank transition points of about 0.050 to about 0.061 inches;
an equivalent root radius of about 0.057 to about 0.061 inches;
a first flank angle relative to the minor axis of about 20 to about 30 degrees;
a root depth of about 0.012 to about 0.020 inches;
a pitch of about three threads per inch; and
a taper of about 1.0 to about 1.5 tapers per foot.

9. The thread structure of claim 1 , further comprising:
a root semi-width at the flank transition points of about 0.052 inches to about 0.055 inches;
an equivalent root radius of about 0.057 to about 0.059 inches;
a first flank angle relative to the minor axis of about 24 to about 28.5 degrees;
a root depth of about 0.013 to about 0.016 inches;
a pitch of about three threads per inch; and
a taper of about 1.0 to about 1.5 tapers per foot.

10. The thread structure of claim 1 , further comprising:
an equivalent root radius of about 0.057 to about 0.059 inches;
a first flank angle relative to the minor axis of about 24 to about 28.5 degrees;
a crest width of about 0.1 to about 0.2 inches; and
a pitch of about three threads per inch.

11. A rotary shouldered connection (RSC), the RSC comprising:
a first tubular having a longitudinal axis and a pin end carrying a thread structure;
a second tubular having a box end carrying a thread structure, wherein the pin end and the box end are threadedly connected;
the thread structure including a thread extending helically in spaced thread turns, the thread comprising:
a crest extending between a first flank and a second flank;
a root extending between the thread turns, the root having a curvature defined by a portion of an ellipse tangentially adjoining the first and second flank at respective flank transition points, the ellipse having a major axis extending parallel to the longitudinal axis and a minor axis extending perpendicular to the major axis and through a root bottom;
a root semi-width at the flank transition points of about 0.050 to about 0.061 inches; and
an equivalent root radius of about 0.057 to about 0.061 inches.

12. The RSC of claim 11 , wherein the thread comprises:
a root depth of about 0.012 to about 0.020 inches.

13. The RSC of claim 11 , wherein the thread comprises:
an equivalent root radius of about 0.057 to about 0.059 inches;
a first flank angle relative to the minor axis of about 24 to about 28.5 degrees;
a crest width of about 0.1 to about 0.2 inches; and
a pitch of about three threads per inch.

14. The RSC of claim 11 , wherein the thread comprises:
a root semi-width at the flank transition points of about 0.050 to about 0.061 inches;
an equivalent root radius of about 0.057 to about 0.061 inches;
a first flank angle relative to the minor axis of about 20 to about 30 degrees;
a root depth of about 0.012 to about 0.020 inches;
a pitch of about three threads per inch; and
a taper of about 1.0 to about 1.5 tapers per foot.

15. The RSC of claim 11 , wherein the thread comprises:
a root semi-width at the flank transition points of about 0.052 to about 0.055 inches;
an equivalent root radius of about 0.057 to about 0.059 inches;
a first flank angle relative to the minor axis of about 24 to about 28.5 degrees;
a root depth of about 0.013 to ab about out 0.016 inches;
a pitch of about three threads per inch; and
a taper of about 1.0 to about 1.5 tapers per foot.

16. A drilling system, comprising:
a drilling string comprising a rotary shouldered connection (RSC) having a thread structure on a tubular support member having a longitudinal axis, the thread structure including a thread extending helically in spaced thread turns, the thread comprising:
a crest extending between a first flank and a second flank; and
a root extending between the thread turns, the root having a curvature defined by a portion of an ellipse tangentially adjoining the first and second flank at respective flank transition points, the ellipse having a major axis extending parallel to the longitudinal axis and a minor axis extending perpendicular to the major axis and through a root bottom;
a root semi-width at the flank transition points of about 0.050 to about 0.061 inches; and
an equivalent root radius of about 0.057 to about 0.061 inches.

17. The drilling system of claim 16 , wherein the thread comprises:
a root depth of about 0.012 to about 0.020 inches.

18. The drilling system of claim 16 , wherein the thread comprises:
an equivalent root radius of about 0.057 to about 0.059 inches;
a first flank angle relative to the minor axis of about 24 to about 28.5 degrees;
a crest width of about 0.1 to about 0.2 inches; and
a pitch of about three threads per inch.

19. The drilling system of claim 16 , wherein the thread comprises:
a root semi-width at the flank transition points of about 0.050 to about 0.061 inches;
an equivalent root radius of about 0.057 to about 0.061 inches;
a first flank angle relative to the minor axis of about 20 to about 30 degrees;
a root depth of about 0.012 to about 0.020 inches;
a pitch of about three threads per inch; and
a taper of about 1.0 to about 1.5 tapers per foot.

20. The drilling system of claim 16 , wherein the thread comprises:
a root semi-width at the flank transition points of about 0.052 to about 0.055 inches;
an equivalent root radius of about 0.057 to about 0.059 inches;
a first flank angle relative to the minor axis of about 24 to about 28.5 degrees;
a root depth of about 0.013 to about 0.016 inches;
a pitch of about three threads per inch; and
a taper of about 1.0 to about 1.5 tapers per foot.

Assignees

• Schlumberger Technology Corp

Inventors

• Li Ke Ken
• Song Fei
• Singh Rakesh
• Du Michael Hui
• Collins Anthony L
• Moriarty Keith

Classifications

• F16L15/06 Primary

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

• F16L15/001

  with conical threads · CPC title

• E21B17/042

  Threaded · CPC title