Directional Turbodrill : A turbodrill which can follow the hole curvature developed with a bent sub, usually shorter in length than a straight-hole turbodrill. (Bul D20)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}