气举反循环钻进工艺高发钻铤折断事故分析

Analysis of high incidence drill collar breakage in air lift reverse circulation drilling

气举反循环钻进工艺在漏失地层施工具有明显的优势,但是经过几个工地正反循环工艺的对比,发现相比于正循环,反循环钻进有钻具易折断的明显弱点。为了指导施工、充分发挥反循环钻进的优势和摒弃其弱点,对钻具在孔内的受力情况进行了分析,总结了反循环钻具易折断的原因,提出了预防措施,有效地减少了施工中钻具折断的事故。

Air lift reverse circulation drilling has obvious advantages for lost formation.But through the comparison of positive and reverse circulation drilling processes at several sites,it is found that there is the obvious weakness of easy breakage of drilling tools in reverse circulation compared with direct circulation.In order to guide drilling operations,give full play to the advantages of reverse circulation and eliminate the weakness of reverse circulation,the stress of drilling tools in the hole is analyzed with summarization of the causes for easy breakage of drilling tools in reverse circulation drilling.Subsequent drilling has verified that breakage of drilling tools were effectively reduce.