Estimation of the Formation Temperature from the Inlet and Outlet Mud Temperatures While Drilling Geothermal Formations

Formation temperature is an important parameter in geothermal drilling since it affects drilling fluid, operations and equipment, through mud temperatures. In this study formation temperatures of the five geothermal wells in Germencik-Omerbeyli field were estimated by using mud inlet and outlet temperatures obtained during drilling. GTEMP wellbore thermal simulation model was used to estimate the formation and bit temperatures of five wells. With the formation and bit temperature estimations of GTEMP and mud inlet and mud outlet temperature data from field; depth-temperature plots were obtained for two cases. In Case 1, cooling tower effect on mud temperatures was neglected whereas in Case 2 it was taken into account. When cooling tower effects were considered, the results were in accord with those obtained using Horner plot approach. The lowest and highest deviations of the estimations for the formation temperature were 1.5% and 24.5% respectively.