Radius of Curvature

This algorithm is the industry standard. The drilled section is treated as a curve inscribed on a cylindrical surface with a vertical axis. The vertical and horizontal projections of this curve are assumed to be the arcs of circles whose radii are calculated as functions of the build up rate and the rate of change of the azimuth. Radius of Curvature is expressed using the following formula (from “Formulas and Calculations for Drilling, Production, and Workover,” Lapeyrouse, Norton J., Gulf Publishing Co.):