Coupling for rods

Patent metadata

Field	Value
Publication number	US-10435955-B2
Application number	US-201514633593-A
Country	US
Kind code	B2
Filing date	Feb 27, 2015
Priority date	Jun 5, 2014
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

A cold worked and spinodally-hardened copper alloy comprising from about 8 to about 20 wt % nickel, and from about 5 to about 11 wt % tin, the remaining balance being copper, and having a 0.2% offset yield strength of at least 75 ksi, is used to form a sucker rod coupling or subcoupling. Each coupling is formed from a core having two ends, each end having an internal thread. These box ends engage the pin of a sucker rod or other rod. The exterior surface of the core includes grooves running between the two ends.

First claim

The invention claimed is:

1. A coupling for a sucker rod, comprising:
a spinodally-hardened copper-nickel-tin alloy comprising from about 8 to about 20 wt % nickel, and from about 5 to about 11 wt % tin, the remaining balance being copper, wherein the alloy has a 0.2% offset yield strength of at least 95 ksi and a Charpy V-notch impact energy of at least 22 ft-lbs at room temperature;
wherein the coupling is formed from a core having a first end and a second end, each end containing an internal thread having a box thread size; and
wherein the internal threads on the first end and the second end have the same box thread size, and wherein a bore runs through the core from the first end to the second end, the internal threads of each end being located within the bore.

2. The coupling of claim 1 , wherein the spinodally-hardened copper-nickel-tin alloy comprises about 14.5 wt % to about 15.5 wt % nickel, and about 7.5 wt % to about 8.5% tin, the remaining balance being copper.

3. The coupling of claim 1 , wherein each end also includes an end surface, each end surface having a counterbore.

4. The coupling of claim 1 , wherein the internal threads have a Rockwell C hardness (HRC) of about 20 to about 40.

5. The coupling of claim 1 , wherein the first end and the second end of the coupling are tapered downwards, linearly, or parabolically.

6. A rod string, comprising:
a first rod and a second rod, each rod including an end having a pin with an external thread; and
a coupling formed from a core having a first end and a second end, each end containing an internal thread having a box thread size, wherein the internal threads on the first end and the second end have the same box thread size, and wherein a bore runs through the core from the first end to the second end, the internal threads of each end being located within the bore;
wherein the internal thread of the first end of the coupling is complementary with the external thread of the first rod, and the internal thread of the second end of the coupling is complementary with the external thread of the second rod; and
wherein the coupling comprises a spinodally-hardened copper-nickel-tin alloy comprising from about 8 to about 20 wt % nickel, and from about 5 to about 11 wt % tin, the remaining balance being copper, wherein the alloy has a 0.2% offset yield strength of at least 95 ksi and a Charpy V-notch impact energy of at least 22 ft-lbs at room temperature.

7. A pump system comprising:
a downhole pump;
a power source for powering the downhole pump; and
a rod string located between the downhole pump and the power source;
wherein the rod string comprises:
a first rod and a second rod, each rod including an end having a pin with an external thread;
a coupling formed from a core having a first end and a second end, each end containing an internal thread having a box thread size, wherein the internal threads on the first end and the second end have the same box thread size, and wherein a bore runs through the core from the first end to the second end, the internal threads of each end being located within the bore;
wherein the internal thread of the first end of the coupling is complementary with the external thread of the first rod, and the internal thread of the second end of the coupling is complementary with the external thread of the second rod; and
wherein the coupling comprises a spinodally-hardened copper-nickel-tin alloy comprising from about 8 to about 20 wt % nickel, and from about 5 to about 11 wt % tin, the remaining balance being copper, wherein the alloy has a 0.2% offset yield strength of at least 95 ksi and a Charpy V-notch impact energy of at least 22 ft-lbs at room temperature.

Assignees

• Materion Corp

Inventors

• Nielsen William D
• Nielsen Diane M
• Grensing Fritz C

Classifications

• C22C9/02 Primary

  with tin as the next major constituent · CPC title

• E21B43/121

  Lifting well fluids (monitoring of down-hole pump systems E21B47/008) · CPC title

• E21B17/042 Primary

  Threaded · CPC title

• F16L15/00

  Screw-threaded joints; Forms of screw-threads for such joints · CPC title

• C22C9/06 Primary

  with nickel or cobalt as the next major constituent · CPC title