US 12,084,975 B2
High modulus liners in PDM stators with diameter reliefs compensating for rotor tilt
Peter Thomas Cariveau, Houston, TX (US); Timothy Mark Miller, Klein, TX (US); and Jing Lu, Houston, TX (US)
Assigned to Abaco Drilling Technologies LLC, Houston, TX (US)
Filed by Abaco Drilling Technologies LLC, Houston, TX (US)
Filed on Oct. 6, 2023, as Appl. No. 18/482,153.
Application 18/482,153 is a continuation of application No. 18/048,336, filed on Oct. 20, 2022, granted, now 11,808,153.
Application 18/048,336 is a continuation of application No. 17/891,593, filed on Aug. 19, 2022, abandoned.
Application 17/891,593 is a continuation of application No. 17/221,698, filed on Apr. 2, 2021, granted, now 11,421,533, issued on Aug. 23, 2022.
Claims priority of provisional application 63/004,263, filed on Apr. 2, 2020.
Prior Publication US 2024/0044251 A1, Feb. 8, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. F01C 1/10 (2006.01); E21B 4/02 (2006.01); F04C 2/107 (2006.01); F04C 13/00 (2006.01)
CPC F01C 1/101 (2013.01) [E21B 4/02 (2013.01); F04C 2/1075 (2013.01); F04C 13/008 (2013.01); F04C 2240/10 (2013.01); F04C 2250/30 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A positive displacement motor (PDM) power section, comprising:
a rotor and a stator, the rotor configured to be received within the stator, the rotor having a rotor length such that a first portion of the rotor length has a substantially uniform transverse cross-sectional profile;
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 contour length includes an outlet region starting at the contour outlet end and extending up to 25% of the contour length towards the contour inlet 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 outlet region 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 more than 0.0002 inches per inch of first relief length;
wherein the elastomer liner has a tensile stress greater than 800 psi at 100% elongation; and
wherein all of the first relief length opposes the first portion of the rotor length when the rotor is received within the stator.