The goal of most horizontal drilling projects is to place a long horizontal hole in a narrow vertical target. To accomplish this objective in the most economical manner, requires a build design that will hit the target without numerous bottom hole assembly changes and a rig that can handle the torque and drag loads produced by the drillstring in the horizontal hole. This paper describes several methods for designing the build curve that offer improved methods for hitting a small horizontal target while using a single bottom hole assembly for the angle building portions of the hole. The paper also presents a novel method for estimating the torque and drag forces for typical drillstrings in a horizontal hole.

Keywords:
curvature rate, tangent interval, build curve, horizontal target, hori zonta 1, displacement, horizontal hole, directional drilling, approximation, simple tangent build curve
Subjects:
Drilling Operations, Directional drilling
Copyright 1989, Society of Petroleum Engineers
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