Maximum Set-Down weight and Maximum Overpull are important limiting parameters in the design of Coiled Tubing (CT) operations. In the past, these have been calculated using time-consuming iterative approaches that may need 20 or more iterations using a CT forces simulator. We describe here a more efficient approach that allows the computation of these parameters directly, with a very low computational overhead. The procedure is based on the behavior of partial derivatives that describe axial force-transmission along the CT. The procedure and its mathematical basis are discussed, and an illustrative example is presented. Besides being faster, this procedure also provides physical insight into the force transmission in CT. It can also be used to predict the lock-up depth and maximum reach in CT operations.

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