定向钻工艺管道穿越沁河防洪影响研究

摘要

针对近年来在沁河下游防洪确保堤段实施的几处采用大型定向钻工艺穿越沁河管道工程施工中出现的问题,分析了定向钻工艺管道施工影响沁河下游防洪安全的主要因素、定向钻工艺管道施工发生严重冒浆等意外情况的原因以及某工程施工时未发生冒浆的施工经验.结果表明:①采用定向钻工艺全程穿越沁河管道工程可能会对沁河下游防洪构成安全威胁;②受穿越管线通过的地层承载力差、地层不均匀等不利地质条件影响,以及现有定向钻穿越施工工艺水平与泥浆压力控制手段的局限,不能确保施工钻进过程中泥浆压力处于可控范围,也不能确保施工钻进过程中绝对不冒浆;③由于河道管理部门没有监控设备,缺乏监控手段,因此难以对定向钻穿越施工工艺与泥浆压力控制情况实施全程、实时、有效的监管.建议:①在地质条件薄弱堤段慎用定向钻施工工艺全程穿越沁河下游河道;②委托安全评估机构对已建采用定向钻工艺穿越施工的管线进行安全评估;③加强已建定向钻工艺穿越沁河管道工程的观测;④编制防守预案,做好应对.%In view of the problems appeared in the construction of Qinhe pipeline project using of large directional drilling technology in sec?tion of flood control in the lower Qinhe River in recent years,the main factors affecting the flood control safety in the lower Qinhe River,the causes of serious accidents such as serious slurry spillover during directional drilling and the construction experience of no slurry during con?struction were analyzed. The results show that a)the use of directional drilling technology through Qinhe pipeline project may pose a security threat to the flood control in the lower Qinhe River;b)influenced by unfavorable geological conditions such as poor bearing capacity and un?evenness of strata through the crossing pipeline and the limitations of the existing construction technology level of directional drilling and the control means of mud pressure,it cannot ensure that the mud pressure is in a controllable range during the process of construction drilling and it cannot ensure that the slurry is absolutely no slurry during the process of construction drilling and;c)due to lack of monitoring devices and lack of monitoring means, the river management department is unable to carry out full, real?time and effective supervision for directional drilling crossing construction process and mud pressure control. It suggests that a)carefully using the directional drilling technology through the whole river of Qinhe River on the geological conditions of weak embankment;b)entrusting scientific research institutions to conduct safe?ty assessment of pipelines built through the construction of directional drilling technology;c)strengthening the observation of the built direc?tional drill through the Qinhe pipeline project and;d)preparing a defensive plan to deal with.