Abstract: Improvement in the drilling of vertical bore holes is achieved by an asymmetrical rotary cone bit having a substantially cylindrical body with a shank formed on the body and extending therefrom along a vertical axis for connection to a drill string. Projecting from the cylindrical body are three journal pins, which pins extend from the end of the body opposite from the shank. These three journal pins are circumferentially displaced such that the rotational axis of the first and second pins are displaced more than 120 degrees and less than 180 degrees. The axis of the third journal pin is circumferentially displaced equidistant from the axis of the other two journal pins. Journaled on the first and second journal pins are first and second roller cutter cones having substantially the same based diameter. Each of these cutter cones has cutting teeth extending from the surface thereof and includes a row of gage cutting teeth.

Abstract: An apparatus for use with an oil well drilling apparatus, including an annular spool interposed permanently between the well blowout preventer stack and the upper bell nipple. The spool receives a plurality of different mandrels, including a test mandrel for testing the seals of the blowout preventers or adapting the drilling apparatus for wireline operations, and a shut-down mandrel for suspending a string of drill pipe within the well casing during a temporary shutdown. The different mandrels are each seated on an internal annular seat in the spool, are each peripherally sealing in the spool above the seat, and are retained by appropriate securing means urging the mandrel against the spool seat.

Abstract: A well instrument is isolated from the high temperatures of a surrounding earth formation by enclosing the instrument within a heat insulative jacket structure, preferably a dewar having spaced walls with a vacuum therebetween, with a heat sink contained in the jacket above the instrument assembly, and with a heat pipe extending upwardly from the instrument assembly to the heat sink and containing a fluid which by evaporation at a lower point and condensation at a higher point will conduct heat upwardly from the instrument assembly to the heat sink but not downwardly therebetween. The heat pipe preferably projects upwardly beyond a top portion of the insulating jacket to the location of a convector element which is exposed to the temperature of fluid or air at the outside of the insulating jacket to transmit heat from within the jacket to its exterior but not in a reverse direction.

Abstract: A device or drift for gauging the inside diameter of pipe comprising an elongated body having a cylindrical outer surface adapted to receive a set of bushings having an outside diameter consistent with the inside diameter of the pipe to be gauged. A plurality of bushing sets are available for use on the body to gauge various weights and sizes of pipe. The body is formed of a hard, heavy material to force the drift through the pipe, while the bushings are formed from a softer material so as to avoid injury to the pipe when the drift passes through it. The bushings are formed with channels and holes axially therethrough to allow the passage of fluid contained in the pipe in order that such fluid will not hinder the movement of the drift.A retriever is also disclosed which may be dropped through the pipe to dislodge a stuck drift. The retriever has a shock transfering end which imparts momentum to the drift in order to free it.

Abstract: A multi position safety valve retainable within an internal portion of a drill string casing (s) and responsive to the greater differential pressure in an internal fluid passage to displace a valve head (32) relative to a valve seat (VS) from its normal partially open position to either a wide open or a closed position. The valve head (32) is attached to a valve stem (30) that extends through a valve chamber and slideably mounted in opposite closed ends of a valve body and returnable to and maintained in the partially open position by opposing compression springs (34) (36) situated between opposite ends (22) of the valve body (VB) and one side of an intermediate abutment (30c) of the valve stem (30) and an intervening disc (38) on the opposite side thereof. The disc 38 is moveable into and out of seating engagement with an intermediate stop (20a) by one spring (34) and the intermediate abutment (30c) of the valve stem respectively.

Abstract: A hydraulically operated downhole pump that is connected to or disposed in a string of tubing, and when operated by pressurized oil from the ground surface, is capable of discharging production fluid, gas, and pressurized oil from the well either separately or in desired combinations thereof. The pump includes an elongate housing preferably of such transverse cross section as to be longitudinally movable through a tubing string, with the pump including universal joint connected upper and lower helical screws that rotate in slidable sealing contact with upper and lower double threaded resilient stator blocks secured to the interior of the housing. As pressurized oil is discharged into the upper end of the housing the upper helical screw and associated stator act as a motor to drive the lower helical screw relative to the lower stator block.