1. ADVANTAGES OF DOWNHOLE MOTOR Increased rate of penetration. Better hole deviation control. Reduction in drill string failure rate. Reduction in wear and tear of the swivel, Kelly, and rotary drives. Reduction in fuel cost, since compared to rotary drilling, less energy is required to power a downhole motor. 2. CONSTITUTION Downhole motors differ in size and performance characteristics, but they share the same basic components as follows (Fig.1) : Crossover Sub Safety Catch Sub Power Section Coupling Assembly Bearing Assembly
