CAJ | 학술논문

U型井在煤层气资源开发中逐渐得到应用，但沿煤层顶板钻进的U型连通井在国内尚属首例。该在进行二次贯通时，由于套管下深距洞穴太远而形成过长水泥塞、固井候凝时间过长而水泥强度太大的原因造成了第一次二次贯通失败。针对这种情况，现场采取在洞穴直井处三级扩孔方法，最终实现了二次贯通，对在扩孔时技术措施进行了较为全面的介绍，并对以后施工提出了相应预防措施。
U형정재매층기자원개발중축점득도응용，단연매층정판찬진적U형련통정재국내상속수례。해재진행이차관통시，유우투관하심거동혈태원이형성과장수니새、고정후응시간과장이수니강도태대적원인조성료제일차이차관통실패。침대저충정황，현장채취재동혈직정처삼급확공방법，최종실현료이차관통，대재확공시기술조시진행료교위전면적개소，병대이후시공제출료상응예방조시。
The U-shaped wells are applied progressively in the CBM resource exploitation in recent years, but the U-shaped penetra-tion drilling along the coal roof still the first time in China. Owing to the long distance of casing lowering depth apart from cave thus formed too long cement plug, too long cementing curing time and too large cement strength brought on the first time failure of the sec-ondary penetration. In allusion to the situation, three staged reaming is used on vertical part of the cave and realized secondary penetra-tion finally. The paper comprehensively introduced technical measures in reaming, and corresponding precautionary measures ad-vanced for later operations.