AN INNOVATION IN 3-D DRILLING TRAJECTORY DESIGN USING CONCEPT OF CONSTANT CURVATURE

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.