用双层岩心管钻进时采取岩心的方法多为干取或使用岩心提取器。但是这两种采取岩心的方法都存在着一定的缺点。“干式采取”不能经常牢靠地将岩心全部提取上来和保证岩心质量。如钻进煤矿时能导致岩心样品的灰份增高等。采用岩心提取器就使得双层岩心管的结 When drilling with double-layer core pipe, the method of taking the core is mostly to dry or use the core extractor. However, both methods of taking a core have some disadvantages. “Dry take” can not always be solid core extraction and to ensure the quality of the core. Such as drilling coal can lead to core samples of ash increased. The use of a core extractor results in a double core tube junction