Abstract Steerable bottom hole assemblies are often used when drilling deviated wells. Planning of such deviated wells often include studies of torque and drag calculations for the planned well-path and BHA's in order to have a fairly good idea of friction and torque to be encountered when drilling. The paper discusses some effects of using steerable bottom hole assemblies or other means of directional control. It is shown in the paper that in extreme situations, extensive use of directional control methods, may result in problems with high drag and torque in the wells. In some cases TD may not be reached due to large doglegs in building parts of the well.