Radial jet drilling (RJD) is a proven stimulation method to increase reservoir contact quickly and affordably while utilizing existing infrastructure and wellbores. RJD exploits a niche within the industry by targeting marginal reservoirs, thin pay zones, heavy oil reservoirs, coal bed methane, low-permeability reservoirs, and old, conventional, low-producing reservoirs. Development of the RJD technology has led to a multi-orifice nozzle, which generates a substantial cutting force (i.e. jet impact force) to penetrate the formation rock and a propulsion force to advance the bit into the formation. Only a handful of previous studies focus on modeling propulsion force to provide reasonable predictions. However, the models require empirically determined parameters to provide an accurate prediction of the propulsion force. This thesis presents a generalized propulsion force model, based on mass, momentum, and energy conservation equations. The model utilizes the discharge coefficient for multi-orifice nozzles to determine the impact and propulsions force generated at each orifice. The predictions of the new model are compared with existing and new measurements and showed reasonable agreement. After validation, the model allows performing a parametric study for further optimization. The results of the parametric study presented extensively in the article can be a good reference for future nozzle designs and hydraulic force calculations for the RJD technology.