The thermal protection technology for high-temperature environment has made great progress in recent years. Restricted by the harsh environment of oil drilling, the design and development of measurement-while-drilling instrument (MWD) for high-temperature wells are still a worldwide issue. Although quite a few scholars have proposed a variety of thermal protection schemes, the feasibility or practical using effect has not been fully verified. Through comparative analysis of various cooling methods, it is considered that the active cooling scheme based on split-Stirling refrigerator is feasible, and a set of active cooling system is designed. The temperature distributions on the circuit cabin are presented. The influences of the structure parameters of circuit cabin, circuit board and refrigerator, the thermal conductivity of insulation material, the cooling power of refrigerator, the circuit board power, the annulus and water eye temperature on the cooling effect are discussed. The results show that the circuit board structure parameters, the insulation material thickness and thermal conductivity, the ratio between circuit board power and cooling power of split-Stirling refrigerator, the temperature difference between water eye and annulus are the key parameters affecting the cooling effect.

高温环境热防护技术近年来取得了长足的进步。受石油钻井恶劣环境的制约，高温井随钻测量仪（MWD）的设计开发仍是世界性课题。虽然不少学者提出了多种热保护方案，但其可行性或实际使用效果尚未得到充分验证。通过对各种制冷方式的对比分析，认为基于分裂斯特林制冷机的主动制冷方案是可行的，并设计了一套主动制冷系统。给出了电路舱上的温度分布。电路舱、电路板和冰箱结构参数的影响，绝缘材料的热导率，讨论了冰箱的冷却功率、电路板功率、环面和水眼温度对冷却效果的影响。结果表明，电路板结构参数、绝缘材料厚度和导热系数、分体斯特林冰箱电路板功率与制冷功率的比值、水眼与环带的温差是影响制冷效果的关键参数。