页岩气井试气施工常见事故处理及预防

Treatment and Prevention of Frequent Accidents in Gas Testing in Shale Gas Wells

页岩气勘探开发是世界级的技术难题,各项工艺技术均在不断探索和应用中走向成熟。分析页岩气试气压裂施工、泵送桥塞-多级射孔联作以及连油钻塞中的常见事故,提出相应的处理与预防方法。其中:压裂施工中最常见的事故是砂堵,可以通过提前针对层位地质特征制订出不同的泵注程序,并在施工过程中根据施工现状及时调整加砂阶段液量和砂比的方法来进行预防;泵送桥塞-射孔联作事故预防的关键在于抓好泵送桥塞前清理干净井筒,泵送过程中平稳操作,遇阻时及时处理等3环节的工作;遇卡钻塞是最常见的事故,在钻塞施工中严格按施工工艺操作,做好限速下管和短起洗井工作,能够有效预防该类事故的发生。

On the basis of analysis of frequent accidents in shale gas test fracturing,pumping bridge plug plus multistage perforation combing operation and coiled tubing plug drilling,this paper presents relevant treatment and prevention measures：1）adopting different pumping procedures in advance aiming to each layer’s geological feature and timely adjusting liquid amount at sand adding period and sand ratio according to operation status to prevent sand plug in fracturing;2）grasping three key points,namely,clearing up wellbore before pumping bridge plug,running smoothly in the course of pumping and timely handling while meeting resistance,to prevent the accident likely to occur in pumping bridge plug plus perforation combing operation;3）doing agood job of rate-limiting tubing downward and short-trip well flushing in drilling plug operation to prevent pipe sticking.