Electrical Submersible Pumps (ESPs) are commonly applied to producing wells in unconventional reservoirs. Typically, the operator places the ESP in the vertical section to minimize installation risks; however, some operators have reported installing ESPs in the lateral section to improve operation and production. This paper will present a study of the interaction between reservoir inflow, wellbore geometry, and ESP operation using a commercial dynamic multiphase flow simulator (OLGA). The study will further quantify the benefits and disadvantages of deploying the ESP in the vertical and lateral sections of a horizontal well. The investigation uses operations data from a Permian basin well, with an ESP operating in the vertical section of a horizontal well. The dynamic simulation model was built and tuned to match the field data with two different production stages: early and late production. Hypothetical cases with the ESP located in the lateral section and with different well geometries (toe-up and toe-down) are also investigated. For the performance evaluation of different ESP deployment positions, the following indicators were considered: (a) production flow rate, (b) likelihood of pressure surging occurrence, and (c) flow pattern and gas volume fraction reaching the ESP system. Finally, the study provides guidelines on the ESP deployment location for improved operation and production.