PVC-U套管在小口径科学实验孔中的应用探讨

Application of PVC-U casing in a small diameter scientific experimental drilling hole

摘要:

根据地质需要，采用XY-6B型钻机在内蒙古棋盘井煤矿区实施了一口设计深度535 m的科学实验孔，终孔孔深540 m，终孔口径133 mm，完钻后需进行地球物理测井工作。为了减小钢套管对入井仪器信号屏蔽，需要按地质设计下入?90 mm PVC-U套管，下PVC-U套管前做了大量准备工作，主要从孔径参数设计、PVC-U套管连接改造、采用导正锥头防止PVC-U套管下入过程发生磨损卡钻及加工滤水管平衡冲洗液浮力等方面入手，顺利完成了该科学实验孔的PVC-U套管下管工作，确保了一系列孔内科学实验工作的顺利完成。

Abstract:

According to the geological needs， XY-6B drill was used to drill a scientific experimental hole with design depth of 535m， and completion depth 540m at ?133mm in the Qipanjing coal mine area， Inner Mongolia. After drilling， geophysical exploration was needed. In order to reduce the shielding of the steel casing to the instrument signal in the drilling hole， PVC-U casing of ?90mm diameter was run into the drilling hole. A lot of preparatory work was done before setting the PVC-U casing， mainly including the diameter parameter design of the drilling hole， modification of PVC-U casing connection mode， use of the guide cone head to prevent the wear and jamming of PVC-U casing during running， processing the screen pipe to balance the buoyancy of drilling mud. As a result， the PVC-U casing was successfully run into the scientific experimental drilling hole， ensuring the smooth completion of a series of scientific experiments.