Numerical Simulation of Wellbore Temperature for Multi-Geothermal Gradients in Guide ZR_1 Geothermal Well, Qinghai, China

摘要

Temperature is a crucial parameter for geothermal drilling. The accurate wellbore temperature can prevent blowout and fracturing formation and ensure the safe drilling. To obtain precise wellbore temperature distribution during the circulation, a wellbore temperature model was developed to account for the transient heat exchange process based on energy exchange mechanisms of wellbore and formation systems during circulation. ZR_1 geothermal well was taken as an example to test the model by COMSOL. The result showed that the model is fit for the actual situation; the error was mainly from the inaccurate parameter. The wellbore temperature decreased with the time, and finally stable. The temperature model which used constant geothermal gradient would easily bring big errors especially high temperature geothermal well. The model adopted multi-geothermal gradients which followed the initial formation temperature can calculate wellbore temperature accuracy.