Optimized fiber reinforced liner material for positive displacement drilling motors

A positive displacement motor comprising:

• a stator comprising a shaped inner surface, (he inner surface comprising at least two radially inwardly projecting lobes extending helically along a selected length of the stator;
• a liner comprising at least two resilient layers and at least one fiber layer, the at least two resilient layers positioned so as to enclose the at least one fiber layer, the liner disposed within the stator so that the liner conforms to the helical shape formed by the at least two radially inwardly projecting lobes;
• and
• a rotor comprising at least one radially outwardly projecting lobe extending helically along a selected length of the rotor, wherein the rotor is disposed inside of the stator and the at least one radially outwardly projecting lobe formed on the rotor is adapted to sealingly engage the at least two radially inwardly projecting lobes formed when the liner conforms to the inner surface of the stator.

A positive displacement motor comprising:

• a stator comprising a shaped inner surface, the inner surface comprising at least two radially inwardly projecting lobes extending helically along a selected length of the stator;
• a rotor comprising at least one radially outwardly projecting lobe formed on an outer surface of the rotor, the at least one radially outwardly projecting lobe extending helically along a selected length of the rotor;
• and
• a liner comprising at least two resilient layers and at least one fiber layer, the at least two resilient layers positioned so as to enclose the at least one fiber layer, the liner disposed on the external surface so that the liner conforms to the helical shape formed by the at least one radially outwardly projecting lobe,
• wherein the rotor is disposed inside of the stator and tie at least one radially outwardly projecting lobe formed when the liner conforms to the outer surface of the rotor is adapted to sealingly engage the at least two radially inwardly projecting lobes formed on the stator.