Granted Patent B2

US 12,486,771 · App. 18/828,379 · Granted Dec 2, 2025

Inventors: Peter Thomas Cariveau (Houston, TX); Timothy Mark Miller (Klein, TX); Jing Lu (Houston, TX)

Assignee: Abaco Drilling Technologies LLC

F01C1/101E21B4/02F04C2/1075F04C13/008F04C2240/10F04C2250/30

Abstract

Claims (51)

1 . A positive displacement motor (PDM) stator, comprising:

a stator, the stator having a longitudinal centerline, the stator further including an internal elastomer liner such that the elastomer liner provides the stator with a stator internal surface, wherein the stator internal surface has lobes therein, wherein the lobes define helical pathways in the stator internal surface, wherein the helical pathways define a contour length between a contour inlet end and a contour outlet end;

wherein the stator provides a design eccentricity at the contour inlet end and an enlarged fit eccentricity at the contour outlet such that the enlarged fit eccentricity is in a range between about 102% and about 120% of design eccentricity;

wherein transverse cross-sections of the elastomer liner taken orthogonal to the longitudinal centerline provide alternating lobes and valleys around a circumference of the stator such that 2× a distance between the longitudinal centerline and a zenith point of the lobes defines a minor diameter and 2× a distance between the longitudinal centerline and a nadir point of the valleys defines a major diameter;

wherein the contour length further includes a first relief length and a second relief length disposed thereon, wherein the first relief length is located nearer the contour outlet end than the second relief length;

wherein the first relief length extends between a first relief length inlet towards the contour inlet end and a first relief length outlet towards the contour outlet end, and wherein the second relief length extends between a second relief length inlet towards the contour inlet end and a second relief length outlet towards the contour outlet end;

wherein the first relief length inlet has a first relief length inlet minor diameter and the first relief length outlet has a first relief length outlet minor diameter, and wherein the second relief length inlet has a second relief length inlet minor diameter and the second relief length outlet has a second relief length outlet minor diameter;

wherein the first relief length outlet minor diameter is larger than the first relief length inlet minor diameter according to a first relief enlargement rate, and wherein the second relief length outlet minor diameter is larger than the second relief length inlet minor diameter according to a second relief enlargement rate;

wherein the first relief enlargement rate is more aggressive than the second relief enlargement rate; and

wherein the first relief length inlet is located at least 10% of the contour length from the contour outlet.

2 . The PDM stator of claim 1 , in which the first relief length inlet is located in a range between about 10% and about 50% of the contour length from the contour outlet.

3 . The PDM stator of claim 1 , in which the first relief length inlet minor diameter increases at least in part towards the first relief length outlet minor diameter according to a first relief taper profile.

4 . The PDM stator of claim 3 , in which the first relief taper profile is non-linear at least in part.

5 . The PDM stator of claim 3 , in which the first relief taper profile is according at least in part to a non-linear function selected from the group consisting of (a) a geometric function, and (b) a logarithmic function.

6 . The PDM stator of claim 1 , in which the first relief length inlet minor diameter increases at least in part towards the first relief length outlet minor diameter according to a first relief step function.

7 . The PDM stator of claim 6 , in which the first relief step function is a spline function at least in part.

8 . The PDM stator of claim 1 , in which the second relief length inlet minor diameter increases at least in part towards the second relief length outlet minor diameter according to a second relief taper profile.

9 . The PDM stator of claim 8 , in which the second relief taper profile is non-linear at least in part.

10 . The PDM stator of claim 8 , in which the second relief taper profile is according at least in part to a non-linear function selected from the group consisting of (a) a geometric function, and (b) a logarithmic function.

11 . The PDM stator of claim 1 , in which the second relief length inlet minor diameter increases at least in part towards the second relief length outlet minor diameter according to a second relief step function.

12 . The PDM stator of claim 11 , in which the second relief step function is a spline function at least in part.

13 . The PDM stator of claim 1 , in which the elastomer liner has a tensile stress greater than 800 psi at 100% elongation.

14 . The PDM stator of claim 1 , in which the elastomer liner has an elongation at break between 80% and 270%.

15 . A positive displacement motor (PDM) stator, comprising:

a stator, the stator having a longitudinal centerline; and

the stator further including an internal elastomer liner such that the elastomer liner provides the stator with a stator internal surface, wherein the stator internal surface has lobes therein, wherein the lobes define helical pathways in the stator internal surface, wherein the helical pathways define a contour length between a contour inlet end and a contour outlet end;

wherein transverse cross-sections of the elastomer liner taken orthogonal to the longitudinal centerline provide alternating lobes and valleys around a circumference of the stator such that 2× a distance between the longitudinal centerline and a zenith point of the lobes defines a minor diameter and 2× a distance between the longitudinal centerline and a nadir point of the valleys defines a major diameter;

wherein the contour length further includes a first relief length disposed thereon, wherein the first relief length extends between a first relief length inlet towards the contour inlet end and a first relief length outlet towards the contour outlet end;

wherein the first relief length inlet has a first relief length inlet minor diameter and the first relief length outlet has a first relief length outlet minor diameter;

wherein the first relief length outlet minor diameter is larger than the first relief length inlet minor diameter by a first relief enlargement rate such that the first relief enlargement rate is more than 0.0002 inches per inch of first relief length; and

wherein the first relief length inlet minor diameter increases towards the first relief length outlet minor diameter at least in part according to a step function and at least in part according to a linear function.

16 . The PDM stator of claim 15 , in which the step function is a spline function at least in part.

17 . The PDM stator of claim 15 , in which the elastomer liner has a tensile stress greater than 800 psi at 100% elongation.

18 . The PDM stator of claim 15 , in which the elastomer liner has an elongation at break between 80% and 270%.

19 . The PDM stator of claim 15 , in which:

the contour length further includes a second relief length disposed thereon;

wherein the first relief length is located nearer the contour outlet end than the second relief length;

wherein the second relief length extends between a second relief length inlet towards the contour inlet end and a second relief length outlet towards the contour outlet end;

wherein the second relief length inlet has a second relief length inlet minor diameter and the second relief length outlet has a second relief length outlet minor diameter;

wherein the second relief length outlet minor diameter is larger than the second relief length inlet minor diameter according to a second relief enlargement rate; and

wherein the first relief enlargement rate is more aggressive than the second relief enlargement rate.

20 . The PDM stator of claim 19 , in which the first and second relief lengths are contiguous.

21 . A positive displacement motor (PDM) stator, comprising:

a stator, the stator having a longitudinal centerline; and

the stator further including an internal elastomer liner such that the elastomer liner provides the stator with a stator internal surface, wherein the stator internal surface has lobes therein, wherein the lobes define helical pathways in the stator internal surface, wherein the helical pathways define a contour length between a contour inlet end and a contour outlet end;

wherein transverse cross-sections of the elastomer liner taken orthogonal to the longitudinal centerline provide alternating lobes and valleys around a circumference of the stator such that 2× a distance between the longitudinal centerline and a zenith point of the lobes defines a minor diameter and 2× a distance between the longitudinal centerline and a nadir point of the valleys defines a major diameter;

wherein the contour length further includes a first relief length disposed thereon, wherein the first relief length extends between a first relief length inlet towards the contour inlet end and a first relief length outlet towards the contour outlet end;

wherein the first relief length inlet has a first relief length inlet minor diameter and the first relief length outlet has a first relief length outlet minor diameter;

wherein the first relief length outlet minor diameter is larger than the first relief length inlet minor diameter by a first relief enlargement rate such that the first relief enlargement rate is more than 0.0002 inches per inch of first relief length; and

wherein the first relief length inlet minor diameter increases towards the first relief length outlet minor diameter according to a non-linear function.

22 . The PDM stator of claim 21 , in which the non-linear function is selected from the group consisting of (a) a geometric function, and (b) a logarithmic function.

Assignments (5)

Continuity (6)

References Cited (48)