Patents by Inventor Harold A. Sreshta

Harold A. Sreshta has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20200149353
    Abstract: A polycrystalline-diamond cutting element for a drill bit of a downhole tool. The cutting element includes a substrate and a diamond table bonded to the substrate. The diamond table includes a diamond filler with at least one leached polycrystalline diamond segment packed therein along at least one working surface thereof. The cutting element may be formed by positioning the diamond table on the substrate and bonding the diamond table onto the substrate such that the polycrystalline diamond segment is positioned along at least one working surface of the diamond table. A spark plasma sintering or double press operation may be used to bond the diamond table onto the substrate.
    Type: Application
    Filed: January 13, 2020
    Publication date: May 14, 2020
    Applicant: National Oilwell DHT, L.P.
    Inventors: Deepthi Raj Setlur, Michael D. Hughes, Mark Jonathan Francis, Harold A. Sreshta, Guodong Zhan, Russell C. Gilleylen, JiinJen Albert Sue
  • Patent number: 10590704
    Abstract: A downhole tool comprises a body made of a metal or metal alloy. In addition, the downhole tool comprises a coating disposed on the body. The coating includes at least 75 vol % tungsten carbide having an average grain size less than 1.0 ?m. The content of tungsten carbide in the coating with a grain size less than 0.5 ?m is between 40 and 64 vol % of the coating.
    Type: Grant
    Filed: June 28, 2012
    Date of Patent: March 17, 2020
    Assignee: NATIONAL OILWELL VARCO, L.P.
    Inventors: Jiinjen Albert Sue, Harold Sreshta, Rajagopala Pillai
  • Patent number: 10570667
    Abstract: A polycrystalline-diamond cutting element for a drill bit of a downhole tool. The cutting element includes a substrate and a diamond table bonded to the substrate. The diamond table includes a diamond filler with at least one leached polycrystalline diamond segment packed therein along at least one working surface thereof. The cutting element may be formed by positioning the diamond table on the substrate and bonding the diamond table onto the substrate such that the polycrystalline diamond segment is positioned along at least one working surface of the diamond table. A spark plasma sintering or double press operation may be used to bond the diamond table onto the substrate.
    Type: Grant
    Filed: November 25, 2014
    Date of Patent: February 25, 2020
    Assignee: NATIONAL OILWELL DHT, L.P.
    Inventors: Deepthi Raj Setlur, Michael D. Hughes, Mark Jonathan Francis, Harold A. Sreshta, Guodong Zhan, Russell C. Gilleylen, JiinJen Albert Sue
  • Patent number: 9631435
    Abstract: A fixed cutter drill bit for drilling a borehole in earthen formations includes a blank assembly and a matrix crown fixably mounted to the blank assembly. The blank assembly includes an annular mandrel and a plurality of elongate studs fixably coupled to the mandrel. The mandrel has a first end distal the crown and a second end engaging the crown. In addition, the mandrel includes a plurality of bores extending axially from the second end. Each elongate stud has a first end disposed within one of the bores and a second end disposed in the crown distal the mandrel.
    Type: Grant
    Filed: December 10, 2013
    Date of Patent: April 25, 2017
    Assignee: NATIONAL OILWELL DHT, L.P.
    Inventors: Michael Garner, Jan Edgar Marshall, Harold A. Sreshta
  • Patent number: 9604345
    Abstract: A composite material and a methods of making and using the composite material, wherein the composite material provides improved wear resistance and fracture toughness to hard-facing and matrix materials for down hole drilling tools.
    Type: Grant
    Filed: November 1, 2013
    Date of Patent: March 28, 2017
    Assignee: NATIONAL OILWELL DHT, L.P.
    Inventors: Ying Wang, Wesley Craig Arceneaux, Sr., Jiinjen Albert Sue, Harold A. Sreshta
  • Patent number: 9364936
    Abstract: Composite materials for use with a drill bit for drilling a borehole in earthen formations. The composite material comprises a first pre-infiltrated hardphase constituent and a second pre-infiltrated hardphase constituent. The second pre-infiltrated hardphase constituent is a carbide which comprises at least 0.5 weight % of a binder and at least about 1% porosity. The composite material further comprises an infiltrant.
    Type: Grant
    Filed: October 12, 2011
    Date of Patent: June 14, 2016
    Assignee: NATIONAL OILWELL DHT, L.P.
    Inventor: Harold A. Sreshta
  • Patent number: 9309767
    Abstract: A stator for a progressive cavity pump or motor comprises a tubular housing having a central axis. In addition, the stator comprises a stator insert coaxially disposed within the housing. The stator insert has a radially outer surface that engages the housing and a radially inner surface defining a helical-shaped through bore extending axially through the stator insert. The stator insert includes an insert body and an insert liner attached to the insert body. The insert body is radially positioned between the housing and the insert liner. The insert body comprises a reinforcement structure and a plurality of voids dispersed within the reinforcement structure.
    Type: Grant
    Filed: August 15, 2011
    Date of Patent: April 12, 2016
    Assignee: NATIONAL OILWELL VARCO, L.P.
    Inventors: Harold A. Sreshta, Jiinjen Albert Sue, Stefan M. Butuc, Jan Edgar Marshall
  • Publication number: 20150322719
    Abstract: A downhole tool comprises a body made of a metal or metal alloy. In addition, the downhole tool comprises a coating disposed on the body. The coating includes at least 75 vol % tungsten carbide having an average grain size less than 1.0 ?m. The content of tungsten carbide in the coating with a grain size less than 0.5 ?m is between 40 and 64 vol % of the coating.
    Type: Application
    Filed: June 28, 2012
    Publication date: November 12, 2015
    Applicant: NATIONAL OILWELL VARCO, L.P.
    Inventors: Jiinjen Albert Sue, Harold Sreshta, Rajagopala Pillai
  • Publication number: 20150233188
    Abstract: A drill bit for cutting through a downhole metal structure includes a bit body having a central axis and a bit face. The bit body is configured to rotate about the central axis in a cutting direction. In addition, the bit includes a cutting structure disposed on the bit face. The cutting structure includes a plurality of circumferentially spaced blades and a plurality of primary cutter elements mounted to each blade. Each primary cutter element has a forward-facing primary cutting face. Each primary cutter element is made of a whisker ceramic composite.
    Type: Application
    Filed: September 25, 2013
    Publication date: August 20, 2015
    Applicant: National Oilwell DHT, L.P.
    Inventors: Charles Leonard Wright, II, Harold A. Sreshta, Jiinjen Albert Sue
  • Publication number: 20150176335
    Abstract: A polycrystalline diamond compact formed in an in-situ boron-doped process. The in-situ boron-doped process includes consolidating a mixture of diamond crystals and boron-containing alloy via liquid diffusion of boron into diamond crystals at a pressure greater than 5 Gpa and at a temperature greater than the melting temperature of the boron-containing alloy, typically less than about 1450° C.
    Type: Application
    Filed: February 26, 2015
    Publication date: June 25, 2015
    Inventors: Jiinjen Albert Sue, Harold Sreshta
  • Publication number: 20150159440
    Abstract: A fixed cutter drill bit for drilling a borehole in earthen formations includes a blank assembly and a matrix crown fixably mounted to the blank assembly. The blank assembly includes an annular mandrel and a plurality of elongate studs fixably coupled to the mandrel. The mandrel has a first end distal the crown and a second end engaging the crown. In addition, the mandrel includes a plurality of bores extending axially from the second end. Each elongate stud has a first end disposed within one of the bores and a second end disposed in the crown distal the mandrel.
    Type: Application
    Filed: December 10, 2013
    Publication date: June 11, 2015
    Inventors: Michael Garner, Jan Edgar Marshall, Harold A. Sreshta
  • Publication number: 20150122552
    Abstract: A composite material and a methods of making and using the composite material, wherein the composite material provides improved wear resistance and fracture toughness to hard-facing and matrix materials for down hole drilling tools.
    Type: Application
    Filed: November 1, 2013
    Publication date: May 7, 2015
    Inventors: Ying Wang, Wesley Craig Arceneaux, SR., Jiinjen Albert Sue, Harold A. Sreshta
  • Publication number: 20150107908
    Abstract: A hardmetal composite used as wear-resistant surfaces and inlays in earth-engaging equipment includes more than one hardphase. At least one hardphase has a high average particle size, for example, from 100 ?m to 2000 ?m. The hardphases vary in terms of particle size, hardness, and binder content, and at least one hardphase includes a particulate constituent capable of plastic deformation that comprises at least 1% residual porosity.
    Type: Application
    Filed: December 29, 2014
    Publication date: April 23, 2015
    Inventors: Harold Sreshta, Eric F. Drake, Douglas B. Caraway
  • Patent number: 8997900
    Abstract: A polycrystalline diamond compact formed in an in-situ boron-doped process. The in-situ boron-doped process includes consolidating a mixture of diamond crystals and boron-containing alloy via liquid diffusion of boron into diamond crystals at a pressure greater than 5 Gpa and at a temperature greater than the melting temperature of the boron-containing alloy, typically less than about 1450° C.
    Type: Grant
    Filed: December 15, 2010
    Date of Patent: April 7, 2015
    Assignee: National Oilwell DHT, L.P.
    Inventors: Jiinjen Albert Sue, Harold Sreshta
  • Publication number: 20150075877
    Abstract: A polycrystalline-diamond cutting element for a drill bit of a downhole tool. The cutting element includes a substrate and a diamond table bonded to the substrate. The diamond table includes a diamond filler with at least one leached polycrystalline diamond segment packed therein along at least one working surface thereof. The cutting element may be formed by positioning the diamond table on the substrate and bonding the diamond table onto the substrate such that the polycrystalline diamond segment is positioned along at least one working surface of the diamond table. A spark plasma sintering or double press operation may be used to bond the diamond table onto the substrate.
    Type: Application
    Filed: November 25, 2014
    Publication date: March 19, 2015
    Inventors: Deepthi Raj Setlur, Michael D. Hughes, Mark Jonathan Francis, Harold A. Sreshta, Guodong Zhan, Russell C. Gilleylen, JiinJen Albert Sue
  • Patent number: 8945720
    Abstract: A hardmetal composite used as wear-resistant surfaces and inlays in earth-engaging equipment includes more than one hardphase. At least one hardphase has a high average particle size, for example, from 100 ?m to 2000 ?m. The hardphases vary in terms of particle size, hardness, and binder content, and at least one hardphase includes a particulate constituent capable of plastic deformation that comprises at least 1% residual porosity.
    Type: Grant
    Filed: August 6, 2009
    Date of Patent: February 3, 2015
    Assignee: National Oilwell Varco, L.P.
    Inventors: Harold Sreshta, Eric F Drake, Douglas B Caraway
  • Patent number: 8944789
    Abstract: A progressive cavity type motor or pump including a stator insert with a reinforcing agent dispersed in a manner to improve properties of the stator insert. The reinforcing agent may be a fiber, nanotube, metal, ceramic, or polymer. A dispersing agent may be used to obtain a homogenous distribution. A magnetic reinforcing agent may be incorporated into a stator insert. The stator insert is subjected to a magnetic field to orient the magnetic reinforcing agent in a particular orientation. The magnetic field may also reposition the magnetic reinforcing agent within the stator insert. The stator insert may be formed by injection molding, transfer, or compression molding among other methods.
    Type: Grant
    Filed: August 22, 2011
    Date of Patent: February 3, 2015
    Assignee: National Oilwell Varco, L.P.
    Inventors: Stefan Butuc, Jiinjen A. Sue, Harold A. Sreshta, Joshua A. Sicilian
  • Patent number: 8919463
    Abstract: A polycrystalline-diamond cutting element for a drill bit of a downhole tool. The cutting element includes a substrate and a diamond table bonded to the substrate. The diamond table includes a diamond filler with at least one leached polycrystalline diamond segment packed therein along at least one working surface thereof. The cutting element may be formed by positioning the diamond table on the substrate and bonding the diamond table onto the substrate such that the polycrystalline diamond segment is positioned along at least one working surface of the diamond table. A spark plasma sintering or double press operation may be used to bond the diamond table onto the substrate.
    Type: Grant
    Filed: October 24, 2011
    Date of Patent: December 30, 2014
    Assignee: National Oilwell DHT, L.P.
    Inventors: Deepthi Raj Setlur, Michael D. Hughes, Mark Jonathan Francis, Harold A. Sreshta, Guodong Zhan, Russell C. Gilleylen, JiinJen Albert Sue
  • Patent number: 8814968
    Abstract: A thermally conductive sand shell molding system allows for controlling heat flow in a molten metal infiltrate powdered metal drill bit molding system to differentially cool the mold system to control differential shrinking and accompanying stress concentrations.
    Type: Grant
    Filed: January 13, 2011
    Date of Patent: August 26, 2014
    Assignee: National Oilwell Varco, L.P.
    Inventors: Alan Honggen Jiang, Harold Sreshta
  • Patent number: 8535408
    Abstract: A hardmetal composition comprises tungsten carbide in an amount greater than 50 weight percent of the hardmetal composition. In addition, the hardmetal composition comprises a binder material consisting of at least 90 weight percent nickel, a binder flux between 3.5 to 10.0 weight percent chosen from the group consisting of boron and silicon, and less than 1.0 weight percent other components.
    Type: Grant
    Filed: January 24, 2012
    Date of Patent: September 17, 2013
    Assignee: Reedhycalog, L.P.
    Inventors: Jiinjen Albert Sue, Harold Sreshta, Rajagopala Pillai