Drilling with New-Generation Positive Displacement Motors

ABSTRACT Successful penetxation of harder formations at greater drilling depths will play an important role in the continued exploration program of our nation to meet energy needs of the future. As drilling costs continue to rise, more efficient drilling methods must be developed and implemented if economies are to be realized. Recent advancements in drilling technology, coupled with significant engineering improvements, have spawned a new generation of positive displacement downhole mud motors designed for long interval straight hole drilling with natural or man-made diamond bits or with conventional three-cone rock bits. Field results of the past 24 months have demonstrated that these motors are now cost-competitive with rotary drilling methods. The advantages of increased penetration, deviation control and reduced casing wear contribute to a lower cost per foot of hole drilled compared to rotary techniques. To be successful, these new-generation motors must be used effectively and efficiently so that maximum tool life can be realized.