CAJ | 학술논문

脉冲射流钻井技术具有高效清岩能力，但其提速机制还不十分清楚。通过建立围压条件下单喷嘴脉冲射流井底清岩物理模型，对脉冲射流清岩过程进行了数值模拟研究，分析了影响脉冲射流清岩效果的主要因素。结果表明，非稳态旋流是脉冲射流提高清岩效果的主要原因之一，在相同排量条件下，脉冲射流清岩效率比连续射流平均提高约1~1.6倍。脉冲射流清岩效率随着喷嘴直径和入口流速的增大而增大；围压对脉冲射流清岩过程影响较小；低频率脉冲射流的清岩总体效果较好；随着岩屑粒径增大，井底冲击区域内岩屑分布非均匀性增强，脉冲射流清岩效率降低。研究结果对指导脉冲射流提速技术的工程实践具有一定的参考价值。
맥충사류찬정기술구유고효청암능력，단기제속궤제환불십분청초。통과건립위압조건하단분취맥충사류정저청암물리모형，대맥충사류청암과정진행료수치모의연구，분석료영향맥충사류청암효과적주요인소。결과표명，비은태선류시맥충사류제고청암효과적주요원인지일，재상동배량조건하，맥충사류청암효솔비련속사류평균제고약1~1.6배。맥충사류청암효솔수착분취직경화입구류속적증대이증대；위압대맥충사류청암과정영향교소；저빈솔맥충사류적청암총체효과교호；수착암설립경증대，정저충격구역내암설분포비균균성증강，맥충사류청암효솔강저。연구결과대지도맥충사류제속기술적공정실천구유일정적삼고개치。
The drilling technology with pulsed jet is highly capable of cleaning the cuttings, but its acceleration mechanism remains unknown. By establishing a physical model for bottom hole cleaning cuttings by pulsed jet with single-nozzle under conifning pressure, the numerical simulation research was conducted on the whole process of cleaning cuttings by pulsed jet, and the main factors affecting the cleaning cuttings effect by pulsed jet was analyzed. The research ifnding shows that unsteady state rotational lfow is one of the main reasons for improvement of cleaning cuttings effect by pulsed jet. Under the same lfow rate, the cleaning cuttings efifciency by pulsed jet is about 1-1.6 times that of continuous jet in average. The efifciency of cleaning cuttings by pulsed jet increases with the increase of nozzle diameter and inlet lfowrate. The conifning pressure has small effect on the process of cleaning cuttings by pulsed jet. The overall effect of cleaning cuttings by low frequency pulsed jet is good, with the increase of particle sizes, the heterogeneity of cuttings distribution within the impact area at hole bottom is intensiifed and the efifciency of cleaning cuttings by pulsed jet is reduced. The resulting conclusions provide a theoretical guidance for research on acceleration technique by pulsed jet.