A steerable bottom hole assembly may be used for drilling both a curved section and straight section of the borehole, with the bottom hole assembly including a reamer beneath the downhole motor 12. The bottom hole assembly includes a bit 30 having a bit face defining a bit diameter, and a gauge section...http://www.google.es/patents/US6848518?utm_source=gb-gplus-sharePatente US6848518 - Steerable underreaming bottom hole assembly and method
Steerable underreaming bottom hole assembly and method
