Abstract: In a drilling system in which the hook is guided for vertical travel, by a pair of guide cables supported in the tower, so as to be in a given azimuth while handling drill pipe in the hole, an improvement in the hook mechanism which provides for rotating the hook through a selected angle with respect to the travelling block, as an aid to stacking the stands of drill pipe in the tower during the process of coming out of the hole, and vice versa.

Abstract: In a drilling apparatus for handling strings of drill pipe on a drilling rig which includes a lift member or travelling block positionable over a borehole and carrying a pair of bails or links supported from the lift member at their upper ends, and having open loops at their lower ends which serve to lift the elevators. A link powered control device is attached to the lifting member so that, on command, it will spread the links so that they can be removed from one elevator and will draw the links backwards, away from the borehole, for attachment to a second elevator. The invention comprises a setback platform mounted on the drilling floor with spaces on its surface for positioning a second elevator while a first elevator is positioned on the rotary table. Hydraulic or pneumatic cylinders are provided, for moving an elevator from the rotary table to the surface plate of the setback platform, and back to the rotary table.

Abstract: An apparatus is provided for use on a drilling rig for rapidly attaching a blowout preventer sub to the upset female threaded end of drill pipe, including a collar removably attached to the blowout sub, a horseshoe member slidably positionable on the drill pipe below the upset end and engageable with upset end, a telescoping frame interconnecting the collar and horseshoe member and an arm and linkage means for moving the collar and blowout towards each other so that the blowout preventer sub is brought into engagement with the drill pipe upset end after which the blowout sub may be rotated to threadably engage it with the drill pipe. After threadable engagement of the blowout sub with the drill pipe the attachment means may be removed.

Abstract: Apparatus for measurement, above the surface of the ground, of an electrical current flowing in a buried pipeline, comprises a pair of magnetic flux detectors oriented with their axes vertical, and spaced apart, in a frame, which is moved along the earth at a substantially constant elevation above the surface, with the plane through the two vertical detectors substantially perpendicular to the direction of the pipe. Means are provided, including a vertical core and coil centered on the frame, for indicating the position of the frame laterally with respect to the buried pipe. There is also a second core and coil displaced laterally from the first core and coil, for determining the depth of the pipe below the frame. When the frame is centered over the pipe and there is current in the pipe, flux will pass upwardly through a first flux detector core and downwardly through the second flux detector core.