دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a long steel casing that uses an inclined plane to cause the bit to deflect from the original borehole at a slight angle. Whipstocks are sometimes used in controlled directional drilling, in straightening crooked boreholes, and in sidetracking to avoid unretrieved fish.

n: A device inserted in a well bore used for deflecting or for directional drilling.

a hardened steel ramp along which a mill turns as it cuts a hole in the side of the casing to start a sidetrack or lateral wellbore.