CPC E21B 41/0021 (2013.01) [E21B 33/06 (2013.01)] | 24 Claims |
24. A method of drilling, with a drill string suspended from a drilling rig, a wellbore into a subterranean zone, the method comprising:
passing the drill string through a blow-out preventer of the drilling rig as the drill string is raised or lowered within the wellbore;
attaching, to an upper end of the blow-out preventer stack, a bell nipple assembly, the bell nipple assembly positioned below a rig floor of the drilling rig and comprising:
a tubular main body defining a central passage with a first diameter and having a central axis; and
a catcher assembly comprising:
one or more magnets attached to an inner surface of one or more inwardly-sloping inner surfaces of the bell nipple assembly;
drilling the wellbore with the drill string;
catching, during the drilling and by the catcher assembly, fluids falling from the rig floor or from an exterior surface of the drill string;
directing, by the catcher assembly, the fluids to the tubular main body; and
attracting, by the one or more magnets, a magnetic object falling within the interior of the catcher assembly towards the one or more inwardly-sloping inner surfaces.
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