Extended reach with CT has become a major issue in recent years. Fracing wells in stages often requires the use of drillable bridge plugs, which are drilled out with CT. As the extended reach of wells increases, the reach of CT also needs to be extended. Drillpipe is often able to reach farther due to its ability to rotate. The inability of CT to rotate makes extending the reach more challenging. This paper will present the theory and modeling which helps determine the maximum reach in a horizontal well before helical lockup or incipient yielding of the pipe occurs. It will present a parametric study for L shaped wells which shows the significance of each parameter in extending the reach. The parameters include pipe OD and wall, vertical hole ID, horizontal hole ID, friction coefficient, kick-off point, build rate, force on end (weight on bit) and helical buckling initiation. Several techniques for extending the reach including rotation, vibration, lubrication, tractors, OD and ID taper, pump down, etc. will be examined to quantify how effective they are or could be in extending the reach (or increasing the force on end), and how practical they are to implement. Field cases in which the desired reach was unattainable will be studied to try and understand what may have been done to reach farther.
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