山西榆次大口径供水井施工工艺

Discussion on Large-diameter Supply Well Construction Technology Used in Yuci,Shanxi

山西榆次南部新近系粉质粘土居多,上部为含卵石砂层,中部为含砾砂层,在施工大口径供水井时存在着井壁维护困难,泥浆上返速度低,孔内岩粉不便清除等问题。以1#井为例,介绍了施工大口径供水井时,采取三次成井的施工工艺,钻井液选用GSP-HPAN-KHm处理剂为主的优质低固相化学泥浆以及应用桥式过滤器的成井工艺,并对在施工中钻探钻参选择,钻井液配方及其参数,防斜以及冲孔换浆、下管填砾、洗井、抽水等工艺措施进行了详细说明。抽水试验显示,该井在降深73m时,出水量为25m3/h,且水质符合生活饮用水标准,完全满足设计与合同要求。

The Neogene System in southern Yuci,Shanxi is mostly silty clay,the Neogene System in southern Yuci,Shanxi is mostly silty clay,in upper part contains pebbly sands,middle part gravelly sands.In the construction of large-diameter supply wells,problems of difficult well wall maintenance,low velocity of mud returning,rock flour in well not easy to clean out etc.are existed.To take the No.1 well as an example,introduced large-diameter supply well completion technologies of 3 hole-ins construction technology,mainly GSP-HPAN-KHm treated high quality low solid chemical mud,application of bridge type water filter pipe;and explained technical measures of drilling parameter selection,drilling fluid formula and parameters,deviation preventing,well flushing and mud changing,pipe lowering and gravel packing,well cleanout and pumping in detail.The pumping test has demonstrated that the well＇s water yield is 25m3/h,when the drawdown is 73m;water quality agreed with drinking water standard,fully satisfied design and contract requirements.