The principle of downhole thermal generation technology is to integrate the ther-mal generation equipment and place it downhole to transport air,fuel,and water.Based on the high-pressure combustion injection mechanism,the fuel and air are fully burned in the combustion chamber,and the mixed water is vaporized by the generated high-temperature and high-pressure flue gas,generating a composite thermal fluid and injecting it into the formation.Due to the limitation of wellbore size,compared with the surface multi-element thermal fluid generator,the output displacement of the downhole thermal generator needs to be increased by four times under the condition of reducing the outer diameter by one time.After the structural change,the main problems faced are whether the combustion is suffi-cient,whether the heat exchange is effective,and whether the output temperature and dis-placement meet the design requirements.In response to these problems,this paper establish-es a simulation model for the flow and heat transfer of an downhole thermal generator,and obtains the temperature and flow field distribution of the generator during operation.The re-sults show that the internal combustion of the generator is relatively complete,with a maxi-mum flue gas temperature of about 1 600 K,an outlet flue gas temperature of about 1 300 K,and an outlet temperature of 370 K,the water temperature rises by nearly 80 K,but with the increase of water flow rate,the outlet temperature of the flue gas decreases.Moreover,when the water flow rate is too high,such as 43.4 t/h,the highest temperature of the flue gas and the outlet flue gas temperature actually increase.The highest temperature of the lining also slightly increases,and the outlet temperature decreases,resulting in a decrease in cooling performance.
关键词
渤海稠油/井下多元热流体/燃烧仿真/温度场/流场
Key words
Bohai heavy oil/downhole multi-element thermal fluid/combustion simulation/temperature field/flow field
维普
万方数据