Constructing a multilateral closed-loop geothermal system (MCLGS) requires directional tools and magnetic ranging tools in the bottom-hole assembly (BHA) to drill and intersect the wellbores and create the closed loop. The levelized cost of energy (LCOE) of such an MCLGS is largely driven by rock temperature – the hotter the rock, the more energy that is produced from a given well configuration, and the lower the levelized cost. However, these tools have a maximum temperature limit above which they are no longer functional. To enable drilling of high-temperature rock formations and thereby decrease the LCOE, methods for estimating the temperature of the BHA critical components are required. To simulate drilling, two models of increasing complexity were developed. The first model is a one-dimensional pseudo steady state wellbore + thermal resistance model capable of estimating the temperature and pressure profile of the drilling mud throughout the drill pipe and annulus. This model allows for the understanding of key performance drivers and technology requirements to achieve high-temperature drilling.