| 摘要 |
The present invention comprises an improved method and apparatus for taking core samples, wherein a core drilling assembly driven by a downhole fluid motor is retrievably housed within a drilling tool of larger diameter, and wherein a plurality of cores may be cut and retrieved to the surface by withdrawal of the core drilling assembly by including an extender in the core drilling assembly each time it is brought to the surface and returned to the drilling tool, and sequentially cutting another core without postdrilling the previously cored formation section. The extenders may be included either above or below the motor used to drive the core drilling assembly, and are preferably of tubular configuration with screw-threaded connectors at their ends for rapid insertion in and removal from the core drilling assembly.
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