Abstract The benefits of running rotary steerable tools have been widely advertised and accepted. Borehole quality, higher ROP’s and less torque and drag are all potential benefits to running rotary steerable tools. Is the rotary steerable tool a catch all for all applications? The purpose of this paper is to review when a rotary steerable tool can be most effective and when it might be better to just run high performance mud motors.
The development of rotary steerable tools has changed the directional drilling and even performance drilling landscape forever. Rotary steerable tools can allow longer laterals than ever before. They allow casing to be run where it was difficult to run before and allow weight transfer when it was impossible to get it.
But in some applications, it might be more cost effective to use high performance mud motors. A properly engineered BHA with the right drilling tools and motor / bit combination can out drill a rotary steerable system in many applications.
This paper will review the proper application of rotary steerable tools and also present case studies where properly engineered mud motor BHA’s have out performed rotary steerable BHA’s.