US 4,305,467 AGranted

Blow-out preventer lift system and method

AssigneePower Lift, Inc.

InventorDouglas R. Villines

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Abstract

An apparatus for lifting a blow-out preventer during oil or gas drilling operations includes a base frame which can be manually positioned atop the rotary table of the drilling platform of the drilling rig used to drill the well. The apparatus further includes a pair of winches which can be lowered to preselected positions on the base frame, after positioning the base frame on the rotary table, and secured to the base frame via pins that extend through clevises that are welded to the base frame and through apertured lugs that are welded to the winches and extend into the clevises. The blow-out preventer is lifted by the winches via cables that are wrapped on reels of the winches and passed through the base frame and rotary table to the blow-out preventer to which the cables are attached. The base frame comprises a U-shaped portion and an end beam, attachable to the U-shaped portion at the open end therof via pins, to permit positioning of the base frame on the rotary table at such times that drill pipes and the like extend through the rotary table.

Claims15

Dependent claims

An on-site assemblable apparatus for lifting a load located beneath the drilling platform of a drilling rig, said platform having an aperture formed therethrough providing communication between spaces disposed above and below the drilling platform, comprising:

a base frame supportable by the drilling platform and positionable thereon with respect to the aperture formed through the drilling platform, said base frame having a top, a bottom and opposed first and second ends, and said base frame characterized as having an open-centered structure providing top-to-bottom communication through central portions thereof;
a first winch disposed on the top of the base frame at a preselected position adjacent one end of the base frame;
and
first winch attachment means for pinning the first winch to the base frame in said preselected position of the first winch, the first winch attachment means comprising:
a plurality of clevis forming members attached to the top of the base frame adjacent said one end of the base frame, each clevis forming member comprising a pair of spaced, substantially parallel plates;
a plurality of planar lugs attached to the first winch, each lug extending between the plates of one of the clevis forming members in the preselected position of the first winch, wherein apertures are formed through the plates of the clevis forming members and through the planar lugs, said apertures positioned such that the apertures through the plates of each clevis forming member align with the aperture through the lug disposed therebetween in the preselected position of the first winch;
and
a plurality of pins, each pin extending through the apertures formed through the plates of one of the clevis forming members and extending through the aperture formed through one of the lugs to secure the first winch in a preselected position thereof atop the base frame.

5 more elements

Dependencies are inferred from the claim text.