Abstract: A power tong unit is shown which is operable as a closed head or open head unit. The jaws of the tong unit are rotatable to an extended pipe gripping position from either of opposite directions to make-up or break-out pipe from a single retracted position. An improved jaw for use in the tong unit has contoured gripping surfaces for gripping a wider variety of pipe diameters.

Abstract: A method and apparatus are shown for treating a subsurface earth formation penetrated by a well bore. A proppant is blended with a foamable carrier to form a slurry and the slurry is pressurized to a desired pressure. A gas is added to the pressurized slurry to form a foam. Proppant is then added pneumatically to the pressurized slurry after foaming the slurry and the pressurized fluid is injected into the well bore. The proppant is fed to a manifold which is connected to a source of pressurized gas whereby the application of gas pressure to the manifold serves to blow the proppant into the pressurized foam stream. The foam containing the proppant is then injected into the well in the conventional manner to prop open the fracture.

Abstract: A well cementing composition and method are shown in which a hydraulic cement, water, and a heat actuated matrix control admix are mixed together to provide a cement slurry composition having improved cementing characteristics over a broad temperature range. The admix contains a polyvinyl acetate-polyvinyl alcohol polymer which is insoluble in the slurry composition at ambient temperatures and which has greater than about 95% acetate groups converted to hydroxyl groups. As the circulating temperature rises in the range from about 90.degree. to 140.degree. F., the polymer begins to solubilize and gradually thickens the slurry to combat thermal thinning, fluid loss and settling. A companion cellulosic fluid loss material can be utilized, which is soluble in the slurry at ambient temperatures, to provide initial fluid loss control.

Abstract: A welding torch is shown with a dual shield gas flow for preventing flux buildup on the weld area for welds in confined spaces. The torch has a wire conduit for receiving an advancing supply of welding wire. The wire conduit has a curved end portion for guiding the welding wire toward the weld area and has an opening through which the welding wire extends for welding. A primary gas conduit directs the flow of primary shield gas and has an open, gas dispensing end adjacent the wire conduit opening. A secondary shield gas source located rearward of the gas dispensing end directs the flow of secondary shield gas in the direction of the weld area. The secondary shield gas flow is arranged to surround the primary gas flow in the direction of the weld. The orientation of the primary gas exiting the primary gas conduit induces the flow of secondary gas to change direction to provide additional gas shielding for the weld area.

Abstract: A method for shanking a rock bit utilizing a shank locator and a cone locator, each with tapered surfaces to engage respectively the tail stock of a lathe and the cones of a rock bit, to accurately align the body and the cones of the bit concentric with the design centerline of the bit. The lathe and cone locators each have interior conical surfaces to assure accurate, coaxial alignment of the shank end and the cone end of the bit. A compensating chuck is used to grip the cone end of the bit body and firmly hold the normally uneven surfaces while the threads are being machined.

Abstract: A tubing pressurized firing apparatus is shown for use with a tubing conveyed perforating gun of the type used to perforate a cased well bore. The firing apparatus has a tubular body with an upper end for connection in the well tubing string and with a lower end for connection to a well perforating gun. An inner mandrel is slidably mounted within the tubular body and has a ball seat formed in the interior bore thereof for receiving a ball dropped through the well tubing string. The ball and ball seat together form a pressure tight seal whereby tubing pressure in the well tubing string acts on the inner mandrel to slide the mandrel downwardly within the tubular body. A cocking mechanism located below the inner mandrel within the body includes a lockout member which is initially positioned between a detonating pin and a percussion detonator.

Abstract: An elevator/spider having a series of slips in a tapered bowl and a yoke for pivotally setting slips, a torsion spring is mounted on the body of the elevator/spider. A wire rope connects the torsional spring to the yoke, so that the weight of the slips is counterbalanced by the force of the torsional spring.

Abstract: An earth boring bit has thrust surfaces with enhanced cooling features. The bit has a body with three depending bearing pins. A cutter having an axial cavity is mounted on each bearing pin. The bearing pin and the cavity have mating thrust shoulders. Hard metal inserts or buttons are spaced around each of the shoulders and secured interferingly in mating holes. The buttons in one of the shoulders protrude slightly from the shoulder to allow air to flow past.

Abstract: A tool joint for earth boring drill pipe members has features that increase the amount of torque required to yield the connection. The tool joint has both external and internal make-up shoulders. The pin and box are dimensioned so that the box face contacts the external shoulder while there still is a clearance between the pin face and the internal shoulder. At normal make-up torque, the external shoulder will be tightened to its normal amount. The internal shoulder will tighten to its yield only if additional torque is encountered while drilling. The internal shoulder adds to the amount of torque required to yield the tool joint connection.

Abstract: A well packer is shown which is particularly suitable for use in high temperature well environments, such as in fire flooding and steam injection secondary recovery techniques. The well packer has a central mandrel which extends within an outer assembly, including a top body with an interior bore, which circumscribes the central mandrel. The central mandrel has an external flange region about a portion of the circumference, for contacting abutment members within the top body bore when the mandrel is rotated within the body, to transmit torque to the outer assembly. A seal element in the outer assembly moves radially outwardly between a retracted and extended configuration to sealingly engage the well bore. A slip-cone assembly carried in the outer assembly moves between retracted and extended positions to grip the well bore and anchor the tool.

Abstract: A variable speed drive for an AC motor has features to reduce the speed of the motor if excess temperature is encountered in the variable speed drive system. The system has a rectifier that converts AC supply voltage into DC voltage on the positive and negative rails. Frequency switches switch the DC voltage to power conductors in a sequence and at a rate to determine the selected frequency. The frequency switches are controlled by a DC demand voltage. A temperature sensor provides an electrical response corresponding to the temperature in the system. The temperature response is compared to a reference voltage, and if it exceeds the reference voltage, the comparator provides an output that draws down the demand voltage by a value corresponding to the difference. Lowering the demand voltage lowers the speed of the motor to allow the system to cool under reduced load conditions.

Abstract: A method is shown for fabricating cutter elements for a drill bit, each of the cutter elements being mounted on the drill bit by a mounting stud. A plurality of composite compacts are provided, each of the compacts having an exposed abrasive diamond surface bonded to a carbide substrate portion. The exposed diamond surface is coated with a thin, metal layer, which is relatively easier to grind away in subsequent steps than the diamond surface itself. The coated surface of the compact is then ground to a depth slightly less than the depth of the diamond surface to thereby form a smoothly ground surface for the compact. The smoothly ground surface of the compact is then contacted with a heat sink while the composite compact is brazed to the mounting stud. Each mounting stud so prepared is then affixed to a suitable receiving area provided on the drill bit.

Abstract: A circular seal configuration is shown for sealing the annular clearance between an inner cylindrical member and an outer cylindrical member. A center portion of the seal is made of a compliant elastomer material and is adapted to seal both against the internal diameter of the outer cylindrical member and against the external diameter of the inner cylindrical member. A pair of external backup rings circumscribe the exterior surface of the elastomeric center portion and a pair of internal backup rings circumscribe the interior surface of the elastomeric center portion. The backup rings are of a relatively stiff material but expand independently upon the application of pressure of the elastomeric portion of the seal to provide a zero clearance fit with respect to the surrounding sealing surfaces and prevent extrusion of the elastomer which would cause a seal failure.

Abstract: A liner hanger is shown of the type used to hang a well liner in a surrounding well bore. The hanger includes a tubular mandrel which is connectible in a liner string. A set of circumferentially-spaced gripping slips are mounted about the mandrel with each slip having a spring arm extending therefrom in alignment with the axis of the mandrel. A tapered, slip expander cone is mounted on the mandrel exterior above each of the slips for expanding the slips radially outwardly in the direction of the surrounding well bore responsive to opposite relative movement of the slips and cones. At least one channel guide is formed on the exterior of the mandrel in longitudinal alignment with one of the expander cones. The channel guide includes a slot portion for slidably receiving the spring arm of one of the gripping slips for supporting the slip on the exterior of the mandrel.

Abstract: An electric motor has features for preventing the bearings from rotating. The motor has a stator mounted in a housing. A rotor is rotated within the stator. The rotor is divided into rotor sections, with bearings spaced between. Each bearing has an outer portion that contains outwardly biased pins. The pins engage slot gaps formed in the stator laminations.

Abstract: An earth boring bit having a pressure compensating seal assembly which includes a resilient packing ring, a rigid backup ring and a wave spring to permit axial displacement of the resilient ring in an elongated seal groove while resisting destructive distortions of the resilient ring. The lubrication system has a lubricant volume correlated with the volume of the passages and spaces and the maximum seal displacement. A measured amount of lubricant is withdrawn from the system during assembly for subsequent compression as the bit is lowered into a liquid-filled bore hole to position the seal assembly intermediate the end walls of the seal groove.

Abstract: A continuous flow well bore perforation washing tool is shown of the type having a tubular mandrel with sidewalls defining a flow passage, an upper end for connection in a pipe string and a lower end with means for blocking the flow of fluid from the pipe string through the mandrel. Upper and lower pressure responsive packer assemblies are carried on opposite ends of the mandrel. An outer setting sleeve surrounds the mandrel between the packer assemblies to define an annular chamber between the mandrel and setting sleeve. A continuous flow passage communicates the mandrel interior, the annular chamber, and the well bore. Selectively sized orifices in the setting sleeve form a restriction in a portion of the continuous flow passage. By selectively sizing the orifices, a back pressure buildup can be created in the annular chamber which is used to set the packer assemblies as fluid is continuously flowed through the continuous flow passage.

Abstract: An earth boring bit having a cantilevered bearing shaft and a compensator system to equalize the pressure of the lubricant with the hydrostatic pressure of the drilling fluid surrounding the bit. A rigid face seal assembly, positioned between the cutter and bearing shaft of the bit, moves axially in response to, and to compensate for, dynamic pressure changes in the lubricant adjacent the seal. This is accomplished by the positioning and sizing of resilient energizer rings in relationship to the geometries of the mating grooves between the cutter and shaft and the rigid sealing rings of the face seal assembly.

Abstract: An earth boring rock bit having a sealed bearing with air or gas as the circulating medium. An annular groove is formed in the vicinity of the seal and connected to the interior of the bit for cooling the seal and cleaning debris from the area of the seal. An air groove scraper is mounted on the shaft in the exit port of the annular groove to prevent the annular groove from becoming plugged by debris mixing with moisture in the hole.

Abstract: An anchor seal assembly is shown of the type used to anchor tubing within the bore of a surrounding conduit to provide a seal between the conduit bore and the tubing. A threaded connector circumscribes a portion of the exterior of the tubing. The threaded connector has external threads for matingly engaging a threaded interior surface within the bore of the surrounding conduit. The threaded connector is slidingly received within a recess provided within the exterior surface of the tubing. The tubing recess has a shoulder area at one end thereof for contacting an end of the threaded connector and has a ramp area at the opposite end for contacting the opposite end of the connector. Movement of the tubing in one direction relative to the conduit bore causes the threaded connector to contact the tubing recess shoulder area thereby causing the connector to ratchet into engagement with the threaded interior surface within the bore of the surrounding conduit.