Angle of Buildup : Rate of change (degrees/100 ft) of the inclination angle in the section of the hole where the inclination from the vertical is increasing (refer to "Buildup"). (Bul D20)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}