漂卵石层钻探技术探讨

Discussion on Drilling Technology in Drift Pebble Bed

都江堰平原地区属于冲洪积平原,第四系地层含漂卵石为主。该漂卵石层埋藏浅、厚度大、硬度高、富含孔隙潜水及砂层,工程钻探效率低,给岩土工程地质勘察带来了较大困难。结合都江堰地区勘察工程,在同一位置采用控制变量法,通过控制钻头(金刚石钻头和复合片钻头),护壁材料(预锤击套管、膨润土泥浆、普通植物胶、YP改性植物胶),钻具(单管取心钻具、双管取心钻具)中两个量不变,改变第三个量的组合方案进行钻探对比试验,对比不同变量对漂卵石钻探的质量效益、经济效益,进而得出不同变量对综合钻探效能的影响。得出采用金刚石钻头、YP改性植物胶、(半合管)双管取心的钻探工艺,适用于层厚较大的漂卵石层钻探,满足漂卵石层的工程地质勘察需要。

The Chengdu Plain is a flood plain where the Quaternary System contains a lot of drift pebbles.The drift pebble bed is characterized by shallow burial,large thickness,high hardness,rich pore water and sands,inefficient engineering drilling which brings great difficulty to geotechnical engineering geological exploration.This study compares the quality and economic benefits of different variables(drilling bit,drilling tools,wall protection materials)on drift pebble drilling and effect of different variables on comprehensive drilling efficiency by the use of control variable method.The results indicate that Yp modified vegetable gum,diamond bit and drilling technology of double-pipe coring are suitable for drilling in large-thickness drift pebble beds.