Dog Leg Severity was developed for oil and gas engineers in the field who want a good estimation of the True Vertical Depth and Dog Leg Severity inside of a well. The engineers can use the Well Survey points to enter the Measured Depth, Inclination and Azimuth to calculate the estimated True Vertical Depth and Dog Leg Severity based.

My Calculations are based on the "Minimum Curvature Method" The "Minimum Curvature Method", takes the space vectors defined by inclination and direction measurements and smoothes these onto the wellbore curve by the use of a ratio factor which is defined by the curvature (dog-leg) of the wellbore section. The method produces a circular arc as does the radius of the curvature. This is not, however, an assumption of the method, but a result of minimizing the total curvature within the physical constraints on a section of wellbore. 1: DLS = Arccos (Cos (INCL2 - INCL1) - Sin INCL1 * Sin INCL2 * (1 - Cos (AZIM2 - AZIM1))) 2: Factor = 2 / DL * (Tan (DL / 2)) 3: TVD = SUM (((MD2 - MD1) * (Cos INCL2 + Cos INCL1) / 2) * CF)