Patents Assigned to Christensen, Inc.
  • Patent number: 4352400
    Abstract: A drill bit (10) comprises a cast body (12) with full length wide overlapping integral spiral stabilizer lands (14) between intervening spiral grooves (16), integral short, strong, stubby spiral fingers (18) reinforced by additional web portions (12a) angularly spaced about a short core receiving bore (b) and the longitudinal axis of the body (21).An inclined core ejection passage (P) extends radially outwardly from a spherical inlet end thereof connected to the core receiving bore (b) and at which an inclined hard core cutter breaker inserted within a pocket is situated. The leading sides of the fingers have support surfaces (18a) and shoulders (18b) for supporting engagement with composite abrasive compact cutters comprised of a carbide backing (30a) bonded to the support surfaces (18a) and layers of bonded polycrystalline abrasive particles at opposite cutting sides (30b) inclined at a negative rake angle.
    Type: Grant
    Filed: December 1, 1980
    Date of Patent: October 5, 1982
    Assignee: Christensen, Inc.
    Inventors: Richard H. Grappendorf, Gordon G. Sirrine, John S. Davis
  • Patent number: 4351401
    Abstract: The invention relates to the design of earth bore-hole drill bits embodying shaped preformed cutters containing hard abrasive materials, such as diamonds, the cutters being mounted in companion preformed sockets in the hard metal bit matrix. The extent of penetration of the preformed cutters into the formation being drilled is controlled by providing surface set diamonds embedded in the matrix at or adjacent to its gage portion, the surface set diamonds projecting from the matrix to a much lesser extent than the preformed cutters. As a result, the surface set diamonds can penetrate into the formation only to the extent determined by engagement of the adjacent face of the matrix with the formation. Although the preformed cutters project from the matrix to a greater distance than the surface set diamonds, their extent of penetration into the formation is no greater than that of the surface set diamonds.
    Type: Grant
    Filed: June 13, 1980
    Date of Patent: September 28, 1982
    Assignee: Christensen, Inc.
    Inventor: Coy M. Fielder
  • Patent number: 4336850
    Abstract: A strainer is shown for use with a downhole tool through which drilling fluid is circulated during the drilling of deep oil wells and the like. The strainer provides a plurality of narrow slots which prevent the passage of material therethrough that might be entrained with the fluid and which otherwise would plug ports or nozzles or restrict flow passages below the strainer.
    Type: Grant
    Filed: September 12, 1980
    Date of Patent: June 29, 1982
    Assignee: Christensen, Inc.
    Inventor: Coy M. Fielder
  • Patent number: 4310059
    Abstract: A composite drill collar for drilling bore holes in earth formations including a structural steel outer jacket having a lower end secured to a lower coupling connectable to a drill bit and an upper end secured to an upper coupling connectable to an adjacent drill collar thereabove. An annular heavy metal core of depleted uranium or sintered tungsten is disposed in the jacket and is held in compression therein as by shrink fitting it to the jacket. The structural steel jacket has a heavy wall thickness to carry the bending, torsion, compression, tension and impact loads encountered in the drilling operation, so that such loads are not carried through the core, which has the purpose of increasing the density and mass of the composite drill collar, lessening considerably the tendency for a deviated well bore to be produced.
    Type: Grant
    Filed: January 21, 1980
    Date of Patent: January 12, 1982
    Assignee: Christensen, Inc.
    Inventor: Norman B. Moore
  • Patent number: 4278138
    Abstract: A composite drill collar for drilling bore holes in earth formations including a structural steel outer jacket having a lower end secured to a lower coupling connectable to a drill bit and an upper end secured to an upper coupling connectable to an adjacent drill collar thereabove. An annular heavy metal core of sintered tungsten is disposed in the jacket and is held in compression therein by preloading the lower and upper couplings against the ends of the core, which places the jacket in tension, causing the jacket to contract and grip the periphery of the core. The structural steel jacket has a thick wall to carry the bending, torsion, compression, tension and impact loads encountered in the drilling operation, so that such loads are not carried through the core, which has the purpose of increasing the overall density and mass of the composite drill collar, lessening considerably the tendency for a deviated well bore to be produced.
    Type: Grant
    Filed: January 21, 1980
    Date of Patent: July 14, 1981
    Assignee: Christensen, Inc.
    Inventors: David S. Rowley, James T. Aumann, Lothar H. Waldes
  • Patent number: 4275528
    Abstract: A milling cutter rotatable about an axis and including a cylindrical steel core having helical tapered threads, such as V-shaped threads, diamond grit of a suitable mesh being appropriately secured, as by nickel plating, onto the crests, roots and flanks of the threads, the diamonds being substantially contiguous one another and so related to each other that as the cutter rotates against the work, the individual crest diamonds will first cut the work and eventually break off. Because of the helical pattern, the cutting action will continue, since one of the other diamonds lying in the same transverse plane normal to the axis as the missing diamond will operate upon the work being cut. The loss of the outermost or crest diamonds will expose diamonds in the tapered flanks of the thread to provide cutting points on the cylinder that are operable to cut the work, the flank diamonds traversing the same path normal to the axis of the cutter as the crest diamonds.
    Type: Grant
    Filed: September 10, 1979
    Date of Patent: June 30, 1981
    Assignee: Christensen, Inc.
    Inventor: Eugene E. Higginbotham
  • Patent number: 4272987
    Abstract: This invention relates to improvements in pressure core barrels of the type described in U.S. Pat. No. 3,548,958 wherein a controlled pressure is maintained on a core sample during surfacing. Among the improvements provided by the present invention are an improved arrangement of the pressure control valve, a device for positively latching the assembly (both in the open and closed positions) and the provision of a hydraulic assist for moving the outer barrel to the sealing position. Another particular feature provides an improved device for flushing drilling mud from the core barrel mechanism with sealing valve open and while the core sample is maintained substantially at a pressure at which it was sealed in the bore hole and to facilitate subsequent freezing and removal of the core sample therefrom for analysis.
    Type: Grant
    Filed: December 3, 1979
    Date of Patent: June 16, 1981
    Assignee: Christensen, Inc.
    Inventors: James T. Aumann, Harold G. White
  • Patent number: 4270569
    Abstract: A downhole float valve is normally closed by a spring or other means of applying axial pressure until sufficient pressure of drilling fluid from the surface opens the valve. The valve stem includes a dashpot type housing secured thereto and moving within a fluid filled cylinder. When the valve opens, the movement is controlled by a one-way valve in the housing giving a relatively rapid opening. When pressure of the drilling fluid from the surface is removed, the pressure on the underside of the valve typically assisted by the spring, closes the valve. An adjustable bleed passage in the housing delays this closing for a pre-determined time thus allowing the pressure on the underside of the valve to balance with the pressure on the other side of the valve, but preventing an hydraulic lock or an hydraulic "stuck" situation from occurring.
    Type: Grant
    Filed: October 16, 1978
    Date of Patent: June 2, 1981
    Assignee: Christensen Inc.
    Inventors: Robert G. Reay, Ronald Rachuk
  • Patent number: 4266621
    Abstract: A diamond milling cutter for elongating a laterally opening window in a well casing set in a well bore extending into the earth. The mill has a revolving surface which engages a sidetracking whipstock or the edge of the casing being milled to urge the mill off dead center on the casing edge and enhance the cutting action. One or more eccentric lobes engage the whipstock and cause the mill to revolve on a gyrating or non-fixed axis and effect oscillation of the cutter center laterally of the edge, or a broadly conical nose on the cutting face of the mill provides a wedge action against the casing to laterally move the mill off center and enhance the cutting action.
    Type: Grant
    Filed: August 14, 1978
    Date of Patent: May 12, 1981
    Assignee: Christensen, Inc.
    Inventor: Kenneth A. Brock
  • Patent number: 4265323
    Abstract: The present invention relates to a direct bit drive for deep drilling tools based on the Moineau principles. The drive is divided into two sections disposed end-to-end and co-axially in line, each with a defined helical working space between surfaces shaped in a manner of helical teeth, the said helical working spaces following oppositely turning helical paths and being arranged for the flow therethrough of the working medium, in axially opposite directions. In this manner, the axially thrust forces transmitted to the bit through the direct bit drive by working medium during a drilling operation are reduced.
    Type: Grant
    Filed: September 13, 1979
    Date of Patent: May 5, 1981
    Assignee: Christensen, Inc.
    Inventor: Rainer Juergens
  • Patent number: 4256192
    Abstract: This invention relates to improvements in pressure core barrels of the type described in U.S. Pat. No. 3,548,958 wherein a controlled pressure is maintained on a core sample during surfacing. Among the improvements provided by the present invention are an improved arrangement of the pressure control valve, a means for positively latching the assembly (both in the open and closed positions) and the provision of a hydraulic assist for moving the outer barrel to the sealing position. Another feature provides an improved device for flushing of the mud from the core sample while it is under high pressure to facilitate the further sampling of the core after freezing of the section.
    Type: Grant
    Filed: July 6, 1979
    Date of Patent: March 17, 1981
    Assignee: Christensen, Inc.
    Inventor: James T. Aumann
  • Patent number: 4252102
    Abstract: A cutting element for processing of rock, in particular, but also metal, comprising a support member of cemented carbide or the like hard material and a cutting member made of polycrystalline diamond or like superhard cutting material, said members together forming the cutting element, the cutting element being formed by a cutout of a blank comprising a core zone of the cutting material and an outer zone of the hard material surrounding said core zone in the form of a shell, at least at the periphery thereof. The cutting element typically forms a wedge-shaped section of the blank.
    Type: Grant
    Filed: April 19, 1979
    Date of Patent: February 24, 1981
    Assignee: Christensen, Inc.
    Inventors: Cornelius Phaal, Rainer Jurgens
  • Patent number: 4245709
    Abstract: A stabilizer sleeve, or other sleeve, to be releasably mounted on a drill collar for centering a drill string in a well bore, includes an outer stabilizer sleeve to be mounted on the cylindrical periphery of the drill collar and having an internally threaded bore, the threads of which have conical roots, receiving an externally threaded yieldable sleeve member placed over the drill collar, the crests of the external threads also being conical, rotation of the yieldable member threading it into the stabilizer sleeve and effecting its contraction until its internal surface contacts the periphery of the drill collar, further rotation and tightening of the sleeve member in the stabilizer sleeve compressing the sleeve member against the drill collar periphery, with the crests bearing against the root portions of the internal sleeve threads to secure the sleeve frictionally in position on the drill collar.
    Type: Grant
    Filed: April 27, 1979
    Date of Patent: January 20, 1981
    Assignee: Christensen, Inc.
    Inventor: Tom Manuel
  • Patent number: 4244432
    Abstract: The invention relates to the design of earth bore-hole drill bits employing shaped preform cutters containing hard abrasive materials, such as diamonds, the cutters being mounted in companion preformed sockets in a hard metal bit matrix.
    Type: Grant
    Filed: June 8, 1978
    Date of Patent: January 13, 1981
    Assignee: Christensen, Inc.
    Inventors: David S. Rowley, Bruce H. Walker, Coy M. Fielder
  • Patent number: 4234048
    Abstract: A diamond drill bit for drilling bore holes in earth formations having a body connectible to a drilling string, and provided with a matrix portion of hard metals in which diamonds are surface set at the outer gage portion and adjacent to the bit axis, the hard metal matrix having preformed grooves in which preformed diamond impregnated segments are inserted, which are a mixture of diamonds and hard metals, and secured to the matrix portion by brazing material. During bit rotation in the bore hole, the segments cut the major portion of the hole, the diamonds being dispersed throughout the mass of each segment for selective release from the segment as the diamonds become damaged and lost, thereby exposing new diamonds in the segment at a controlled rate, and thereby producing continual resharpening of the segments. As a result, the drilling rate of the bit is increased, as well as the length of hole drilled.
    Type: Grant
    Filed: June 12, 1978
    Date of Patent: November 18, 1980
    Assignee: Christensen, Inc.
    Inventor: David S. Rowley
  • Patent number: 4231437
    Abstract: An upper stabilizer and a lower reamer are mounted on an integral or one-piece body adapter to be connected in a tubular drilling string for drilling well bores.
    Type: Grant
    Filed: February 16, 1979
    Date of Patent: November 4, 1980
    Assignee: Christensen, Inc.
    Inventors: Gerald S. Swersky, Keith J. Mason
  • Patent number: 4200159
    Abstract: Tool for drilling bore holes and earth formations in which a bit body matrix, including tungsten carbide, has a plurality of carriers secured thereto, to each of which a cutting element is secured by soldering, after the body matrix has been produced, to avoid subjecting the diamond material embodied in the cutting element to the high temperatures required to produce the matrix body, which would have deleterious effects on the diamond. Each carrier has great rigidity and is provided with a plane surface confronted by the plane back surface of the cutting element to provide a desired narrow solder gap between the cutting element and carrier of uniform width, into which the solder is deposited to adhere the cutting element and carrier together, with the load being transmitted directly from the cutter element to the rigid carrier.
    Type: Grant
    Filed: December 2, 1977
    Date of Patent: April 29, 1980
    Assignee: Christensen, Inc.
    Inventors: Eberhard Peschel, Hermann Rathkamp, Klaus Katzorke, Rainer Jurgens
  • Patent number: 4194582
    Abstract: A telescopic shock absorber for incorporation in a drill string connected to a rotary bit for drilling a bore hole in earth formations, the shock absorber including a single spring assembly which is compressed downwardly when sufficient downwardly directed drilling weight is transmitted from the drill string through the shock absorber to the drill bit, and which is compressed upwardly when the internal drilling fluid pressure in the shock absorber fully overcomes the downwardly directed drilling weight, assuring that the spring assembly is in its compressed condition when the shock absorber is telescoped or extended, enabling it to absorb shocks and vibrations incident to the drilling operation and under both conditions.
    Type: Grant
    Filed: June 28, 1978
    Date of Patent: March 25, 1980
    Assignee: Christensen, Inc.
    Inventor: Alfred Ostertag
  • Patent number: 4187061
    Abstract: A progressing cavity fluid motor for driving a drill bit for deep drilling tools is described. Such a motor is mounted on a drill string and is powered by a fluid such as drilling mud. The pump includes a housing, a stator with female helical threads within the housing and a rotor with male helical threads mounted inside of the stator. The drill bit is connected to the rotor. In the present invention the rotor has a threaded surface which is formed of an elastically deformable sleeve supported by a carrier shaft. The sleeve is mounted on the carrier shaft in such a manner as to prevent rotation between the two so that the sleeve drives the shaft by positive engagement between these two elements. Means are arranged for introducing a pressure inside of the elastically deformable sleeve for expanding the sleeve radially outwardly.
    Type: Grant
    Filed: April 27, 1978
    Date of Patent: February 5, 1980
    Assignee: Christensen, Inc.
    Inventor: Rainer Jurgens
  • Patent number: 4186569
    Abstract: A drill string shock absorber has a dual spring system for absorbing vibrations and shock loads during rotary well bore drilling operations. A first spring acts in compression when sufficient weight is set down on the drill bit through the shock absorber to overcome the fluid pressure forces tending to extend the shock absorber, and a second spring acts in compression when the weight applied to the bit through the shock absorber does not overcome the fluid pressure forces. A splined connection transmits torque to the shock absorber during drilling operations, and seals are provided between the telescopic shock absorber components for confining therein a body of lubricant, the pressure of which is equalized with the pressure of drilling fluid flowing through the shock absorber.
    Type: Grant
    Filed: February 21, 1978
    Date of Patent: February 5, 1980
    Assignee: Christensen, Inc.
    Inventor: James T. Aumann