Hole Azimuth Angle : The angle between north and the projection of the hole axis onto a horizontal plane. Angle is referred to either true north, magnetic north, or grid north. (Bul D20)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}