單動雙層巖芯管鉆具結(jié)構(gòu)簡單、操作方便、同軸度好、適用壽命長,能有效地提高巖、礦芯的完整度。
The swivel-tube barrel can effectively increase core recovery rato.suitable for drilling in formations in which oblique hole comes easy.It is effective to assure hole quality.