长春净月区强风化砂岩地层抗钻特性研究

Study on Anti-drilling Characteristics of Strong Weathered Sandstone in Changchun Jingyue District

为解决长春净月区强风化砂岩地层长螺旋钻进可行性及对钻具磨蚀程度问题,对该区域强风化砂岩地层通过抗压强度和完整性试验、全岩分析试验和Cerchar试验进行了研究。研究结果表明:该区强风化砂岩为极软岩,岩体整体破碎,单轴抗压强度平均值为2.49MPa,强风化砂岩成分为石英、钾长石、斜长石和黏土矿物,石英是造成钻具磨蚀的主要成分,浅、中、深部强风化砂岩石英含量分别为4.9%、34.9%、54.8%。通过Cerchar试验获得浅部、中部和深部强风化砂岩CAI值分别为0.68~1.55、1.46~2.27、3.13~4.29,对长螺旋桩机钻具磨蚀程度轻微~中等、中等~很强,很强~极强。因此,判定采用长螺旋钻进工艺可以完成本区域强风化砂岩的钻进;但由于浅、中、深部石英含量的不同导致对钻具产生磨蚀强弱不同,在实际施工时应根据不同岩性调整钻具,提高钻进速度和降低施工成本。

In order to solve the problem of long auger drilling and the degree of drilling abrasion in the strong weathering sandstone Jingyue in Changchun,the strong weathering sandstone strata in this area is studied by compressive strength and integrity test,Cerchar test and whole rock analysis test The The results show that the strong weathered sandstone is extremely soft rock,the rock mass is broken and the average value of uniaxial compressive strength is 2.49 MPa.It is concluded that the long-spiral pile foundation can be used to complete the drilling of strong weathered sandstone in this region.The CAI values of the central,middle and deep weathered sandstones are 0.68 ~ 1.55,1.46 ~ 2.27,3.13 ~ 4.29,The wear degree of the long screw pile is slightly to medium,medium to strong,strong and very strong.Sandstone components are quartz,potassium feldspar,plagioclase and clay minerals.Quartz is the main component of drilling abrasion,and the contents of quartz in shallow,medium and deep are 4.9%,34.9% and54.8%.It is feasible to adopt the long auger drilling process in the strong weathering sandstone Jingyue of Changchun,As the conditions will lead to drilling tool drilling a greater loss,should be replaced according to different lithology to reduce the loss,improve drilling speed and reduce construction costs.