A deviated wellbore drilling system suitable for drilling curved wellbores which have a radius of curvature of approximately 10 to 1,000 feet relative to a vertical or near vertical wellbore comprises a drill string, a drill bit, and a fluid-operated drill motor having a curved or bent housing section for rotating the drill bit independently of the drill string. The drilling motor has an elongate tubular rotor/stator drive section containing a rubber stator and a steel rotor and the housing is bent or curved intermediate its ends. A straight or bent universal section below the bent or curved rotor/stator section contains a universal joint for converting orbiting motion of the rotor to concentric rotary motion at the bit, and a bearing pack section below the universal section contains radial and thrust bearings to absorb the high loads applied to the bit.