中粗砂地层大型定向穿越工程施工工艺

Construction technology of large-scale directional crossing in medium-coarse sand formations

抚河φ1016管道穿越工程地层主要为中粗砂层及砾砂层,地下水丰富,地层无胶结质、整体性差,孔壁稳定性差,大口径定向钻进施工具有相当大的风险。基于此,充分分析了施工层位地质状况,结合以往施工经验确定了该工程采用四级扩孔程序,泥浆选用优质复合型非开挖专用膨润土,并添加高分子纤维素进行增效处理。实践表明,通过分析地层资料、合理设计施工程序、优化选取泥浆参数以及实时控制施工过程,可有效提高水平定向钻进在同类地层施工中的一次成功率。

The formations crossed in Fuhe Ф1016 pipeline project mainly included medium-coarse formations and gravel sand formations, which had abundant groundwater and no cementation, poor integrity and bore wall stability, so large-diameter directional drilling construction in such formations was a high risk procedure. Based on this investigation, this project adopted four-stage broaching procedure through fully analyzing construction horizons, geological conditions and combined with previous construction experience, the drilling mud adopted high quality composite bentonite special for non- excavation operation with polymer cellulose added for treatment improvement. The practice showed that careful analysis of formation data, rational design of construction procedure, mud parameter optimization and selection, as well as real-time control to the construction process can effectively improve the one-time success rate of horizontal directional drilling in similar formation construction. （5 Tables, 1 Figure, 4 References）