Comparative Study of Thermal Behavior During Drilling of Geothermal Wells Using Mud and Air-Water as Drilling Fluids

Abstract

This work presents a comparative study of the thermal behaviour of drilling fluids and surrounding rock when airwater and conventional muds are used as drilling fluids. The computations were carried out with two numerical simulators: TEMLOPIV.2, which is used to compute the transient temperature disturbance when mud is employed, and GEOMIST when air-water mixtures are used as drilling fluid. In this analysis, data from well LV-4 from the Las Tres VÌrgenes Mexican geothermal field are used. The results of simulation were compared with temperatures logged during the drilling process and a good approximation of computed results and field data was obtained. The results also show that the thermal disturbance due to circulation of an air-water mixture has a smaller thermal effect on the surrounding rock than the muds. For this reason, wells drilled with air-water mixture return faster to the undisturbed thermal state.