Stator and rotor profile for improved power section performance and reliability

Patent metadata

Field	Value
Publication number	US-10895256-B2
Application number	US-201816214182-A
Country	US
Kind code	B2
Filing date	Dec 10, 2018
Priority date	Dec 14, 2017
Publication date	Jan 19, 2021
Grant date	Jan 19, 2021

Abstract

A progressing cavity pump or a positive displacement motor includes an external member having three or more lobes and an internal member extending through the external member and having one less lobe than the external member. One of the internal member and the external member rotates with respect to the other. The curvature of a profile of each of the internal member and external member is finite at all points. A ratio of a lobe volume of the external member to a valley volume of the external member enclosed between a minor external member diameter and a major external member diameter is between 0.9 and 1.2. A lobe height of the external member is related to a ratio of a minor internal member diameter to one less than the number of internal member lobes.

First claim

What is claimed is:

1. A progressive cavity pump or a positive displacement motor comprising:
an external member comprising three or more lobes; and
an internal member extending through the external member and comprising one less lobe than the external member,
wherein one of the internal member and the external member rotates with respect to the other,
wherein a curvature of a profile of each of the internal member and external member is finite at all points,
wherein a ratio of a lobe volume of the external member to a valley volume of the external member enclosed between a minor external member diameter and a major external member diameter is between 0.9 and 1.2, and
wherein a lobe height of the external member is related to a ratio of the minor diameter of the external member to one less than the number of lobes of the external member.

2. The progressive cavity pump or positive displacement motor of claim 1 , wherein the lobe height of the external member is between 0.95 and 1.05 times the ratio of the minor diameter of the external member to one less than the number of lobes of the external member.

3. The progressive cavity pump or positive displacement motor of claim 1 , wherein a convexity of the external member profile increases from a peak tip to an inflection point and has a finite maximum near the inflection point.

4. The progressive cavity pump or positive displacement motor of claim 1 , wherein a concavity of the external member profile increases from a valley tip to an inflection point and has a finite maximum near the inflection point.

5. The progressive cavity pump or positive displacement motor of claim 1 , wherein a lobe height of the internal member is related to a ratio of the mean diameter to the number of the lobes of the internal member.

6. The progressive cavity pump or positive displacement motor of claim 1 , wherein a convexity of the internal member profile increases from a peak tip to an inflection point and has a finite maximum near the inflection point.

7. The progressive cavity pump or positive displacement motor of claim 1 , wherein a concavity of the internal member profile increases from a valley tip to an inflection point and has a finite maximum near the inflection point.

8. The progressive cavity pump or positive displacement motor of claim 1 , further comprising a sealing line between the external member and the internal member, wherein a two-dimensional projection of the sealing line is an ellipse, a limaçon, or a closed convex spline.

9. The progressive cavity pump or positive displacement motor of claim 8 , wherein a center of the internal member is located on a major semi-axis of the ellipse.

10. A bottom hole assembly, comprising:
a drill bit at a distal end of a drill string; and
the positive displacement motor of claim 1 axially above the drill bit.

11. A progressive cavity pump or positive displacement motor, comprising:
an external member;
an internal member within the external member; and
a two-dimensional contact line that is a projection of a three-dimensional sealing line between the internal member and the external member,
wherein one of the internal member and the external member rotates with respect to the other,
wherein the two-dimensional contact line is an ellipse, a limaçon, or a closed convex spline.

12. The progressive cavity pump or positive displacement motor of claim 11 , wherein a curvature of a profile of each of the internal member and external member is finite at all points.

13. The progressive cavity pump or positive displacement motor of claim 11 , wherein a ratio of a lobe volume of the external member to a valley volume of the external member enclosed between a minor external member diameter and a major external member diameter is between 0.9 and 1.2.

14. The progressive cavity pump or positive displacement motor of claim 11 , wherein a lobe height of the external member is related to a ratio of the minor diameter of the external member to one less than the number of the lobes of the external member.

15. The progressive cavity pump or positive displacement motor of claim 11 , wherein a concavity of the internal member profile increases from a valley tip to an inflection point and has a finite maximum near the inflection point.

16. A bottom hole assembly, comprising:
a drill bit at a distal end of a drill string; and
the positive displacement motor of claim 11 axially above the drill bit.

Assignees

• Schlumberger Technology Corp

Inventors

• Kolyshkin Anton
• Pushkarev Maxim

Classifications

• F01C1/101 Primary

  Moineau-type · CPC title

• F04C2/1073 Primary

  where one member is stationary while the other member rotates and orbits · CPC title

• F04C2250/20

  of the rotor · CPC title

• F04C2/1075

  Construction of the stationary member · CPC title

• F04C2240/10

  Stators · CPC title