CPC E21B 43/121 (2013.01) [E21B 4/02 (2013.01); F04C 13/008 (2013.01); F04C 2230/20 (2013.01); F04C 2240/10 (2013.01); Y10T 29/49242 (2015.01)] | 19 Claims |
1. A stator for a mud motor, the stator comprising a body made at least partially from a rubber, wherein the rubber has an amount of curing that varies circumferentially along an inner surface and does not vary circumferentially along an outer surface, wherein the amount of curing is between about 50% and at most 90% cured such that a fatigue life of the rubber at the about 50% cured is higher than the fatigue life of the rubber the at most 90% cured, the inner surface further defining a bore through the body wherein the inner surface is configured to cooperate with a rotor and to receive a drilling fluid therethrough.
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