The supercritical carbon dioxide (Sc-Co₂) drilling is a novel drilling technique developed in recent years. A detailed study of temperature and pressure distributions of the Sc-Co₂ jet on the bottom of a well is essensial to the Sc-Co₂ drilling. In this paper, the distributions of pressure and temperature on the bottom of the hole during the Sc-Co₂ jet drilling are simulated experimentally and numerically, and the impacts of the nozzle diameter, the jet length, and the inlet pressure of the Sc-Co₂ jet are analyzed. It is shown that, the bottom hole temperature and pressure increase with the increase of the nozzle diameter, and the bottom hole temperature reduces and the pressure increases first and then decreases with the increase of the jet length, indicating that the jet length has an optimum value. The increase of the inlet pressure can increase the temperature and pressure on the bottom, which has a positive effect on the drilling rate.

中文翻译：

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钻井超临界Co 2射流井底温度和压力分布的实验与数值模拟

超临界二氧化碳（Sc-Co ₂）钻井是近年来发展起来的一种新型钻井技术。对井底Sc-Co ₂射流的温度和压力分布的详细研究对Sc-Co ₂钻井至关重要。本文通过实验和数值模拟了Sc-Co ₂喷射钻井过程中孔底压力和温度的分布，以及喷嘴直径，喷射长度和Sc-Co入口压力的影响。钴₂喷气机进行了分析。结果表明，随着喷嘴直径的增加，井底温度和压力升高，随着射流长度的增加，井底温度降低，压力先升高，然后降低，表明射流长度具有最优值。入口压力的增加可以增加底部的温度和压力，这对钻速有积极影响。