Proposal Since horizontal openhole sections are now being drilled to lengths that exceed 20,000 ft, placement of the completion string (CS) to planned total depth (TD) may not be possible under a proposed drilling plan. During the early years of horizontal-well construction, the hanging weight of the completion string was usually adequate to push it to TD. With the extreme lengths being attempted today, it is important to model the well before attempts are made to run the planned completion to determine 1) whether the strength of the CS can stand the strains (tension, compression, and torque) of installation, and 2) whether there is enough weight in the upper CS to push the lower CS to TD. A software model that uses a wide range of well parameters to enable the operator to predict possible tension loading, compression loading, and torque limits on the CS during installation has long been available. This paper discusses the software and how it can be used in modeling well completion systems. To calculate the applied forces on the completion string requires the use of a wide range of well parameters and a specialized software program that will allow the prediction of loads and stresses that can be safely applied on the CS during installation. If the modeling process indicates that the CS will not stand the stresses of installation without (1) failing from tensile loading, (2) buckling from the compression load, or (3) failing from rotational torque, a different well plan can be devised or other remedies employed. Charts developed from actual case histories illustrate how the use of torque and drag modeling can be advantageous in all phases of well completion.