HEAT TRANSFER MODEL FOR THE PREDICTION OF BOTTOM HOLE CIRCULATING TEMPERATURE WHILE DRILLING

Abstract

In typical drilling operation, bottom hole circulating temperature (BHCT) is one of the key parameters that control the drilling process. Therefore, the lacking of the accurate downhole temperature data can lead to many possible difficulties or even failure when performing the drilling operation or related work. This paper discusses an offshore field with directional wells where the wells encountered harsh environment for downhole drilling components. Relatively high chances of temperature related MWD/LWD failures were also observed. Such a problem generally leads to the delay in operational and financial perspectives. In order to avoid the mentioned issue, we will need an effective tool to foresee the borehole temperature while drilling. In this study, the BHCT shall be mathematically solved from the heat transfer model associated with the field data. This tool is also expected to be compatible with the working environment and to be used specifically in the exact area of work. The results demonstrated similar alignment of BHCT prediction compared to the measured data. Moreover, BHCT adjusted factor were introduced to the prediction model in order to improve model accuracy. The sensitivity analysis results showed that the geothermal gradient significantly affects the predicted BHCT.