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US 2023/0065707 A1Published application
Positive displacement motor stators with diameter reliefs compensating for rotor tilt
AssigneeAbaco Drilling Technologies LLC
InventorsPeter Thomas Cariveau, Timothy Mark Miller, Jing Lu
Life of this patent
Estimating the term…
Abstract
Tapered stator designs are engineered in a positive displacement motor (PDM) power section to relieve stator stress concentrations at the lower (downhole) end of the power section in the presence of rotor tilt. A contoured stress relief (i.e. a taper) is provided in the stator to compensate for rotor tilt, where the taper is preferably more aggressive at the lower end of the stator near the bit.
Claims10
A stator for use in a positive displacement motor (PDM) power section, comprising:
- a stator, the stator having an inlet and an outlet, the stator further having a length L between stator inlet and stator outlet, wherein Zn represents a stator position along L;
- the stator further having an internal elastomer liner such that the elastomer liner provides the stator with a stator internal surface, wherein a contoured portion of the stator internal surface has lobes formed therein, wherein the lobes define helical pathways in the contoured portion of the stator internal surface, wherein zeniths of the lobes at Zn define a stator internal minor diameter DMINn, and nadirs of the pathways at Zn define a stator internal major diameter DMAJn, wherein (DMINn+DMAJn)/2 further defines a stator average diameter DAVEn at Zn;
- and
- a taper formed on the contoured portion of the stator internal surface, the taper commencing at stator position Z1 where Z1 is at least about 0.67L measured from the stator inlet, the taper ending at stator position Z3 where Z3 is about 1.0L measured from the stator inlet, wherein DAVE3≥DAVE1+(0.03×(DMAJ1−DMIN1)/2);
- wherein the elastomer liner extends from at least stator position Z1 to stator position Z3.
2 more elements
A stator for use in a positive displacement motor (PDM) power section, comprising:
- a stator, the stator having an inlet and an outlet, the stator further having a length L between stator inlet and stator outlet, wherein Zn represents a stator position along L;
- the stator further having an internal elastomer liner such that the elastomer liner provides the stator with a stator internal surface, wherein a contoured portion of the stator internal surface has lobes formed therein, wherein the lobes define helical pathways in the contoured portion of the stator internal surface, wherein zeniths of the lobes at Zn define a stator internal minor diameter DMINn, and nadirs of the pathways at Zn define a stator internal major diameter DMAJn, wherein (DMINn+DMAJn)/2 further defines a stator average diameter DAVEn at Zn;
- and
- a taper formed on the contoured portion of the stator internal surface, the taper commencing at stator position Z1 at about 0.67L measured from the stator inlet, the taper ending at stator position Z3 at 1.0L measured from the stator inlet, wherein DMAJ3≥DMAJ1+(0.03×(DMAJ3−DMAJ1)/2);
- wherein the elastomer liner extends from at least stator position Z1 to stator position Z3.
2 more elements
Dependencies are inferred from the claim text.