水力脉冲空化射流技术在非常规钻井中的应用

Application of hydraulic pulse cavitating jet technology in unconventional well drilling

部分非常规井由于地层古老,岩性致密,可钻性差,钻井周期长,钻井过程中遇到的复杂情况增多,机械钻速下降幅度明显增大,同时钻井成本也急剧增加。从非常规钻井施工实际不难发现,采用传统钻井工艺和方式不能解决钻井机械钻速低,钻井周期长等难题。目前,石油专家通过探索研究发现,在水力参数不变的条件下,利用脉冲射流和空化射流能够产生较大的冲击载荷,提高清岩和破岩效率,从而顺利解决了钻井机械钻速低,钻井周期长等难题。通过跟踪、对比分析水力空化射流钻井技术在非常规钻井中的应用情况,研究该技术提高机械钻速的可行性,探索提高水力脉冲空化射流工具结构、水力参数、钻具组合与地层适应性关系,对非常规钻井提速做好技术准备具有重要的现实意义。

For some unconventional wells, due to old stratum and poor drillability, it takes longer drilling period and encounters more complex situation, including obvious decline of mechanical drilling rate and soaring drilling cost. Based on the drilling prac- tice of unconventional wells, it is found that conventional drilling technique cannot slove the problems of low mechanical drilling rate and long drilling period. Through research, oil experts found that, under the conditions of fixed hydraulic parameters, the use of pulse jet and cavitating jet could have a greater impact load, improve the efficiency of rock clearing and rock breaking, and success- fully resolve the problem of low mechanical drilling rate and long drilling period. By tracking and comparative analysis of the appli- cation of hydraulic pulse cavitating jet technology in the drilling of unconventional wells, this paper researched on the feasibility of enhancing mechanical drilling rate by the technology and explored the means to improve the tools structure of the technology, hy- draulic parameters, drilling tools combination and the adaptability of the technology to stratum. All the researches above were of practical meanings in making technical preparation for the improvement of mechanical drilling rate of unconventional wells.