Abstract: An improved rotating drag bit for cutting plastic, sticky, water reactive and shale formations is devised by providing a plurality of large diamond cutters having a circular cutting face in excess of one inch in diameter. Each large cutter is provided with at least one hydraulic nozzle which in turn provides a directed hydraulic flow at the corresponding cutter face. The directed hydraulic flow is positioned to apply a force to the chip which tends to peel the chip away from the cutter face. In addition, the hydraulic flow is positioned with respect to the chip so as to apply an off-center torque to the chip which is used to peel the chip away from the cutter face and toward the gage of the bit. In particular, the nozzle defines a jet which is characterized by a direction and velocity of hydraulic fluid determined by the jet characteristics. The core is generally symmetric about its longitudinal axis and has a length along the longitudinal axis and width perpendicular thereto.

Abstract: A method for manufacturing a reusable package for printed circuits boards in oil tools which is protected from high vibration and high temperature environments is comprised of the steps of vacuum forming a thin layer of mold release film over the printed circuit board. The printed circuit board together with its intimately formed mold release film is then potted in a conventional manner within a protective package filled with a resilient curable foam. The foam is poured in an uncured state around the components of the printed circuit board and cured in place. After the potting material is cured the printed circuit board is removed from the resilient potting material and the mold release layer is stripped from the printed circuit board.

Abstract: A stabilizer for use in controlled directional drilling includes a plurality of spaced and axially extending blade elements each having a blade surface face of hardened material. The blade surface face includes a tapered lead portion and a tapered trailing portion with a flat non-tapered surface face portion therebetween. Each blade surface includes an edge portion in which the leading edge is radiused. Thus constructed, the stabilizer reduces kerfing into the formation and hang-up and change of tool face orientation during navigational drilling. Eccentric stabilizers are also described.

Abstract: A diamond cutter for use in a drill bit having a geometric size and shape normally characterized by unleached diamond product, such as STRATAPAX diamond cutters, can be fabricated by assembling a plurality of prefabricated leached polycrystalline diamond (PCD) elements in an array in a cutting slug. A cutting slug is formed of matrix material which in one embodiment is impregnated with diamond grit. The cutting face of the cutting slug is characterized by exposing at least one surface of each of the PCD elements disposed therein. The diamonds may be set within the cutting slug either in a compact touching array or in a spaced-apart relationship. More than one type of array may also be employed within a single cutting slug. The PCD elements can assume a variety of polyhedral shapes such as triangular prismatic elements, rectangular elements, hexagonal elements and the like. The plurality of diamond elements and the cutting slug are fabricated using hot pressing or infiltration techniques.

Abstract: Jamming caused by absorbent members in sponge core barrels or loss of coring information caused by oil wipes in oil field boreholes in which sponge core coring tools are disposed can be avoided by employing a method and tool wherein the absorbent member is formed in placed in contact about the core after the has been cut and disposed within the inner tube. In the illustrated embodiment, a liquid foam is catalytically formed from two constituent parts. The constituent parts are hydraulically forced from longitudinal chambers defined within the inner tube walls into an area in the throat of the bit where the parts meet and exothermically generate a liquid foam. The liquid foam rises into a plurality of longitudinal open chambers defined within the inner tube. Each of the open chambers has a longitudinal slot defined therethrough which communicates the chamber with the axial bore in which the core is disposed.

Abstract: Multistate mud pulsing is achieved by generating both positive and negative pulses within a drill string by means of a plurality of selectively operable bypass passages around a restriction to primary mud flow within a drill string or by venting to outside of the drill string. A fraction of the hydraulic mud is drawn from a location upstream from the restriction into a valve manifold. The removed fraction of hydraulic mud is selectively communicated from the valve manifold either to a point inside a drill string downstream from the restriction or to a point exterior to the drill string in annulus between the outside of the drill string in the borehole. Mud reinjected downstream from the restriction creates a positive pressure pulse within the drill string. Mud which is diverted to the annulus outside of the drill string creates a negative mud pulse within the drill string.

Abstract: A jarring device for use in drilling comprises first and second members longitudinally relatively movable between a locked position and a released position said device comprising control means including a pair of locking devices each arranged to prevent relative movement between said members until a predetermined force is applied to one of said movable members in either of two longitudinal directions. The control means includes two locking devices each of which locks in one of the two directions.The locking devices may comprise pivotable bolts pivoted on a sliding member so that the free ends of the bolts contact an abutment on one of the movable members to effect locking, the bolts being retracted from engagement with the abutment by movement of the sliding member.

Abstract: A drill bit having thermally stable PCD cutting elements includes a matrix body element having a plurality of spaced cutting elements supported in a body of matrix material such that a substantial portion of the cutter is above the body matrix and a minor portion is received within the body matrix. The cutters have side surfaces exposed and are so positioned that at least in some of the cutters more surface area of one side face is exposed as compared to the other side faces. The cutter support may include a small pad of matrix material to reduce the loading directly on the PCD. In a preferred form the PCD elements are mounted on pads or blades formed by spaced channels. The hydraulics are straight radial flow and improved hydraulic flow is achieved through the use of waterways which concentrate the fluid flow near the face of the cutters. In one form, improved hydraulics are obtained by having one fluid discharge port for each of the radially disposed fluid channels.