Experimental and numerical study on the self-balancing heating performance of a thermosyphon during the process of oil production

The thermosyphon has been widely used in various industries due to its high heat transfer efficiency and large heat flux density, it has the significant value and wide application foreground. In this paper, an experimental rig was established to test the self-balancing heat transfer performance of the thermosyphons with three diameters in an unsteady temperature field, which exists in the actual oil production process. The experimental rig was also able to demonstrate how certain factors can impact on the heat transfer performance of thermosyphon. These factors include the diameter of the pipe, angle, with or without working medium and so on. Based on experimental results, a long thermosyphon made of several hollow sucker rods was designed and manufactured, which has been used in the Su 28 Well situated in the Huabei oilfield in China. Experimental results further indicated that the thermosyphon can effectively transfer the required heat of the fluid from wellbore bottom to wellbore top, causing the temperature of wellhead fluid to increase from 22 °C to 39°C. In addition, a mathematical model is established to simulate the heat transfer process of this thermosyphon. The positive correlation between the simulated results and the experimental data demonstrated the effectiveness of the model. With this model, the heat transfer process of thermosyphon during oil production is simulated, with results indicating that the fluid temperature at the wellhead would increase when the production of oil increases, given a linear tendency pump setting.