B. Guo et al., AN INNOVATION IN 3-D DRILLING TRAJECTORY DESIGN USING CONCEPT OF CONSTANT CURVATURE, Journal of offshore mechanics and Arctic engineering, 115(3), 1993, pp. 202-207
This paper focuses on the use of the 3-D drilling trajectory equations
derived from the concept of constant curvature. It is shown that the
constant curvature equations are specially useful for horizontal drill
ing. Three examples of using the constant-curvature method are present
ed to demonstrate the practical usefulness of the proposed concept. Th
e results obtained reveal that the well trajectory with constant curva
ture is not only consistent with directional performance of deflection
tools, but also yields less dogleg severity. This, in turn, should in
crease the fatigue life of drillstring elements passing through the cu
rved segments of the hole. Finally, drag and torque computations show
that, thanks to less dogleg severity, the drag and torque are expected
to be less in holes designed to have constant wellpath curvature.