The Construction Design Of The Yangliweigou Gold Mine And Application Research Of Flushing Fluid In Water Sensitive Strata

This article is about strong difficulties confronted during the drilling in the Zhouqu project, the main formation of which are fulvous and gray sand-slate, limestone and black carbonaceous slate , and the softness and high water-sensitiveness led to the drilling crumbling and increased the difficulties.Slate was formed through the effect of regional metamorphism, which is a kind of epimetamorphic rock developed from the slight metamorphism of clay rock, siltite or intermediate to siliceous tuff; showing obvious characteristics of slaly structure. Diagenetic slate and limestone are intact,occasionally with less-than-lOcm-long quartz vein in them, the carbonaceous slate of low degree of argillaceous metamorphism is relatively fractured, some of which possesses high level of oxidation,showing a state of tiny granule between 1-5mm; It is the main ore bed in the mining lot,alongside that, it is also the construction challenges and difficulties for high core recovery. It is also mingled with a small number of muscovite, biotite and quartz, with many crack development as well as strong broken and falling phenomenon. In addition to this, the carbonaceous mudstone and peaty deposition exist in an irregular way, which are generally very soft, and the intensity of them declines significantly when encountering water. As the meterage increases,the annular gap becoming smaller after drill rod diameter changed,the difficulties also rises.Aims at the problems above, the author takes hole ZK51712as an example, for the analysis of the borehole structure, the selection of drill equipments and installation, the choosing of drilling technologies, collecting of drill core, and the design of the management and safety construction plan of the whole drilling process,which provide strong technical support for the successful carrying out and completion of the drilling task.The dissertation is mainly about slurry technology of drilling in the water sensitive stratum such as the carbonaceous slate, so as to provide technology support for the smooth completion of on-site drilling .