卵石和沙层定向钻穿越工程施工技术

Engineering Construction Technique with Orientation Drilling to Cross Pebbles and Sand Bed

卵石层是常规定向钻穿越施工的禁区,采用常规工艺扩孔时,因泥浆不能够支撑卵石而形成管线回拖所必需的环形空间,基本无法施工。本文以长庆-乌海-临河输气管道工程黄河定向钻穿越为例,介绍了采取安装套管的方法穿越卵石层,保证钻导向孔、扩孔和回拖的施工技术。

Pebble bed is a restricted area in the cross construction of general orientation drilling. When the normal expanding-hole craft was adopted, the pipeline can not be pull-back because the mud can not prop up the pebble bed. For the Yellow River section between Changqing to Wuhai to Linhe gas pipeline as an example, this paper introduces a method of crossing pebble bed which can ensure the success rates of guiding- hole, expanding-hole and pull-back construction by fixing a sleeve.