GB248993A - An improved coring and reaming tool for rotary well drilling - Google Patents

Abstract

248,993. Cuthill, J., and Oil Well Engineering Co., Ltd. July 8, 1925. Borehole apparatus.-In a well-boring tool in which a reaming cutter is connected to a projecting core - cutter and to the drill tube, flushing water pressing between the latter and an inner core tube, the core-cutter is screwed to the reaming cutter and the core tube is connected either to the core-cutter or to the reaming cutter. In Fig. 1, an outer tube d is fixed to the reaming head g. and the core tube j to a coring cutter i which is threaded to and in advance of the reaming head, the advance being varied by placing washers behind the coring cutter. The coring cutter has internal transverse serrations u in which sand &c. accumulates to hold the core. The reaming head has passages s for the flow of flushing water &c. and has double wedge-shaped notches receiving similarly shaped reaming cutters h which are locked by the coring cutter. One or more ball valves l, m protect the core from the flushing water. The teeth of the coring cutter may be set alternately inwardly and outwardly. In Fig. 8, the core tube j is threaded to the reaming head.