【摘要】 为了研究深井高围压对射流性能的影响，采用一种基于节流控制原理的高围压加载装置，开展了90 MPa围压下单喷嘴连续射流的试验，重点分析了射流轴线动压、喷嘴压降、流量系数等参数随围压的变化规律。结果表明，随着围压的增大（0～90 MPa），射流轴线动压逐步降低后趋于平缓，且喷距越大（无因次喷距2～10），射流衰减幅度越小（幅度由75%下降到50%）；以2倍喷距处为例，喷嘴流量系数呈增长趋势（0.8～0.98），喷嘴压降呈降低趋势，但降低幅度较小（均小于6.25%），理论流速越大（150～350 m/s），则射流轴线动压受围压影响程度越大，喷嘴流量系数提升幅度越小（幅度由22.5%下降到4.5%）；喷嘴内部的空化现象和环境介质对射流的阻力，是引起上述现象的主要原因，可以通过改变射流形式、提高流量系数强化射流性能。研究成果对深井、超深井水射流作业参数的设计选型具有指导意义。更多还原

【Abstract】 In order to study the effect of high confining pressure on jet performance in deep wells,a high confining pressure loading device based on throttling control principle was used to carry out at 90 MPa confining pressure continuous jet with a single nozzle.The changes of jet axis dynamic pressure,nozzle pressure drop,flow coefficient and other parameters with confining pressure were analyzed. The results show that with the increase of confining pressure(0～90 MPa),the dynamic pressure along jet axis tends to change gently after it gradually decreases,and the larger the jet distance(dimensionless jet distance of 2～10),the smaller the jet attenuation amplitude(75% to 50%). For example,at 2 times the jet distance,the nozzle flow coefficient shows an increasing trend(0.8 to 0.98),and the nozzle pressure drop shows a decreasing trend,but the decreasing range is small(both are less than 6.25%),the greater the theoretical flow velocity(150～350 m/s),the greater the influence of the dynamic pressure along the jet axis on the confining pressure,and the smaller the increase of the nozzle flow coefficient(22.5% to 4.5%). The analysis shows that the cavitation phenomenon inside the nozzle and the resistance of the environmental medium to the jet are the main causes of the above phenomena,and the performance of the jet can be strengthened by changing the jet form and improving the flow coefficient. The research results have guiding significance for the design and type selection of water jet operation parameters in deep and ultra-deep wells.更多还原