钻遇涌水地层难点分析及应对措施

Analysis of Difficulties Encountered in Drilling Water-Gushing Formation and Corresponding Measures

川藏铁路林康线路钻探勘察项目,四川华锋钻探工程有限责任公司施工完成了2万多米钻探任务。在项目施工中遇到了多起钻探事故,其中在构造勘察孔钻探中遇到的断层带最为复杂。钻探施工中遇到了涌水、涌砂,掉块、缩径等复杂孔内情况。针对泥页岩的垮塌与缩径现象,采用了强抑制性低失水冲洗液。配合采用改良钻具,增大环空间隙等方式,使孔内岩粉能顺利排出,降低循环泵压。提高了孔壁的稳定。部分孔段计划了花管等隔离方法,可以分导出部分涌水量,减少对泥浆的性能破坏。在川藏线钻探施工中,通过强化钻探参数控制,总结施工经验,客服了在断层带中钻探遇到的涌水涌砂等造成的孔内垮塌,缩径等事故,最终顺利的完成了钻探项目。

Such accidents as water gushing,sand gushing,drop block and shrinkage occurred during the construction of drilling engineering of the Nyingchi-Kangding section of the Sichuan-Tibet Railway.In view of the collapse and shrinkage of shale,the strong inhibition and low water loss flushing fluid with the help of improved drilling tools,increase in the annulus clearance is used.Some sections of the holes were isolated by such methods as bored pipe and so on.