Horizontal drilling is now a well established technique with growing popularity for exploiting a number of reservoirs which would otherwise be uncommercial.

However a horizontal well requires a substantial engineering work, compared to a conventional deviated well. The target has new dimensions. The design of the optimum trajectory must take into account a large number of datum. Directional control is severe. Drags and torque have an increased and adverse action on the overall drilling mechanics. The inverted drill string is a new concept.

This paper provides guide lines for planning a horizontal wellbore. Among the 16 horizontal wells drilled by ELF AQUITAINE, typical application of three different methods are also reported.

Keywords:
directional drilling, drill collar, inclination, bent sub, horizontal departure, assembly, upstream oil & gas, trajectory, drill string, departure
Subjects:
Well Planning, Drillstring Design, Drill Bits, Drilling Operations, Drilling Equipment, Reservoir Characterization, Formation Evaluation & Management, Trajectory design, Directional drilling, Directional drilling systems and equipment
Copyright 1989, SPE/IADC Drilling Conference
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