Abstract

A drilling system including a drill head. The drill head defines a drill head bore and includes a drill head bore closure device. An inner core barrel and an inner core barrel retrieval device may be passed through the interior of the drill string and the drill head bore when the drill head is connected with the drill string and the drill head bore closure device is actuated to an open position. A method of wireline core drilling which includes passing an inner core barrel retrieval device through the drill head bore and into the interior of the drill string when the drill head is connected with the drill string, and removing an inner core barrel and the inner core barrel retrieval device from the interior of the drill string through the drill head bore when the drill head is connected with the drill string.

IPC Classes  ?

• E21B 7/12 - Underwater drilling
• E21B 15/02 - Supports for the drilling machine, e.g. derricks or masts specially adapted for underwater drilling
• E21B 7/124 - Underwater drilling with underwater tool drive prime mover, e.g. portable drilling rigs for use on underwater floors
• E21B 19/14 - Racks, ramps, troughs or bins, for holding the lengths of rod singly or connectedHandling between storage place and borehole
• E21B 25/18 - Apparatus for obtaining or removing undisturbed cores, e.g. core barrels or core extractors the core receiver being specially adapted for operation under water
• E21B 41/04 - Manipulators for underwater operations, e.g. temporarily connected to well heads