Multiple elastomer layer progressing cavity stators
AssigneeDyna-Drill Technologies, Inc.
InventorMajid Delpassand
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Abstract
A progressing cavity stator and a method for fabricating such a stator are disclosed. The progressing cavity stator includes first and second elastomer layers fabricated from corresponding first and second elastomer materials. The first and second elastomer materials are selected to have at least one distinct material property. Exemplary embodiments of this invention may reduce tradeoffs associated with elastomer material selection and may further address the heat build up and subsequent elastomer breakdown in the lobes of prior art stators.
Claims33
A stator for use in a progressing cavity power section, the stator comprising:
- an outer tube;
- a helical cavity component deployed substantially coaxially in the outer tube, the helical cavity component providing an internal helical cavity and including a plurality of internal lobes;
- and
- the helical cavity component further including first and second elastomer layers of corresponding first and second elastomer materials, each of the first and second elastomer materials selected to have at least one distinct material property, the first elastomer layer retained by the outer tube and the second elastomer layer deployed on the first elastomer layer.
A subterranean drilling motor comprising:
- a rotor having a plurality of rotor lobes on a helical outer surface of the rotor;
- a stator including a helical cavity component, the helical cavity component providing an internal helical cavity and including a plurality of internal stator lobes;
- the rotor deployable in the helical cavity of the stator such that the rotor lobes are in a rotational interference fit with the stator lobes, rotation of the rotor in a predetermined direction causing the rotor lobes to (i) contact the stator lobes on a loaded side thereof as the interference fit is encountered, and (ii) pass by the stator lobes on a non-loaded side thereof as the interference fit is completed;
- and
- the internal stator lobes including first and second elastomer layers of corresponding first and second elastomer materials, each of the first and second elastomer materials selected to have at least one distinct material property, the first elastomer layer reinforcing the second elastomer layer, the second elastomer layer disposed to engage an outer surface of the rotor.
A method for fabricating a progressing cavity stator, the method comprising:
- (a) providing first and second stator cores, each of which has at least one helical lobe on an outer surface thereof, the first stator core having major and minor diameters greater than those of the second stator core;
- (b) inserting the first stator core substantially coaxially into a stator tube such that a first helical cavity is formed between the first stator core and the stator tube;
- (c) injecting a first elastomer material into the first helical cavity to form a first elastomer layer, the first elastomer layer retained by the stator tube;
- (d) removing the first stator core;
- (e) inserting the second stator core substantially coaxially into the stator tube such that a second helical cavity is formed between the second stator core and the first elastomer layer;
- (f) injecting a second elastomer material into the second helical cavity to form a second elastomer layer, the second elastomer material selected to have at least one distinct material property from the first elastomer material, the second elastomer layer retained by the first elastomer layer;
- and
- (g) removing the second stator core.
Dependencies are inferred from the claim text.