The coring technology in deep slim hole has been applied in China. It provided dependable core data for exploratory development.

深井小井眼钻井取心技术作为其配套技术，已相继在国内油田应用，为勘探开发提供了可靠的岩心资料。

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The team working on the restoration dug an exploratory hole in the internal floor of the mausoleum building.

BBC: Pentillie work may solve mystery of its original owner

Mr Jessop said the vault was found after archaeologists dug an exploratory hole in the internal floor of the mausoleum and discovered a brick-built roof.

BBC: Pentillie Castle: Body found in knight's grave hunt