Patents by Inventor Prabhakaran Centala
Prabhakaran Centala 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).
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Publication number: 20260226800Abstract: A cutter element for a fixed cutter drill bit configured to drill a borehole in a subterranean formation includes a cylindrical substrate. In addition, the cutter element includes a cutting layer mounted to the substrate. The cutting layer includes a first end engaged with the substrate, a second end opposite the first end along the central axis, and a radially outer surface extending axially from the first end to the second end. The radially outer surface of the cutting layer comprises a cylindrical surface extending axially from the second end to the first end and one or more flats extending axially across the cylindrical surface from the second end to the first end. The cutting layer also includes a cutting surface positioned at the second end of the cutting layer. Further, the cutting layer includes a cutting edge positioned between the cutting surface and the radially outer surface of the cutting layer. The cutting edge is configured to engage the subterranean formation during drilling.Type: ApplicationFiled: April 1, 2026Publication date: August 6, 2026Applicant: NATIONAL OILWELL VARCO, L.P.Inventors: Kian Sheikhrezaei, Bradley S. Blaylock, Prabhakaran Centala, Tom S. Roberts
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Patent number: 12612826Abstract: A cutter element for a fixed cutter drill bit has a central axis and includes a cylindrical substrate and a cutting layer mounted to the substrate. The cutting layer includes a first end engaged with the substrate, a second end opposite the first end, and a radially outer surface extending axially between the first and second ends. In addition, the cutting layer includes a cutting surface positioned at the second end and a cutting tip positioned between the cutting surface and the radially outer surface. Further, the cutting layer includes a first region on the cutting surface having a first surface roughness, and a second region on the cutting surface having a second surface roughness that is higher than the first surface roughness. The second region covers the central axis along the cutting surface, and the first region extends from the second region to the cutting tip.Type: GrantFiled: March 27, 2023Date of Patent: April 28, 2026Assignee: NATIONAL OILWELL VARCO, L.P.Inventors: Kian Sheikhrezaei, Bradley S. Blaylock, Prabhakaran Centala, Tom S. Roberts
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Publication number: 20250354441Abstract: A cutter element for a fixed cutter drill bit configured to drill a borehole in a subterranean formation includes a base portion having a central axis, a first end, a second end, and a radially outer surface extending axially from the first end to the second end. In addition, the cutter element includes a cutting layer fixably mounted to the first end of the base portion. The cutting layer includes a cutting face distal the base portion and a radially outer surface extending axially from the cutting face to the radially outer surface of the base portion. The cutting face includes a planar surface disposed in a plane oriented perpendicular to the central axis and a concave recess extending axially into the planar surface. The planar surface extends circumferentially about the concave recess. The planar surface has an average surface roughness Ra and the concave surface has an average surface roughness Ra.Type: ApplicationFiled: May 12, 2025Publication date: November 20, 2025Applicant: National Oilwell Varco, L.P.Inventor: Prabhakaran CENTALA
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Publication number: 20250223872Abstract: A cutter element for a fixed cutter drill bit has a central axis and includes a cylindrical substrate and a cutting layer mounted to the substrate. The cutting layer includes a first end engaged with the substrate, a second end opposite the first end, and a radially outer surface extending axially between the first and second ends. In addition, the cutting layer includes a cutting surface positioned at the second end and a cutting tip positioned between the cutting surface and the radially outer surface. Further, the cutting layer includes a first region on the cutting surface having a first surface roughness, and a second region on the cutting surface having a second surface roughness that is higher than the first surface roughness. The second region covers the central axis along the cutting surface, and the first region extends from the second region to the cutting tip.Type: ApplicationFiled: March 27, 2023Publication date: July 10, 2025Applicant: NATIONAL OILWELL VARCO, L.P.Inventors: Kian Sheikhrezaei, Bradley S. Blaylock, Prabhakaran Centala, Tom S. Roberts
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Publication number: 20080099252Abstract: A two-cone drill bit that exhibits improved stability. In one embodiment, the two-cone drill bit has a first and a second roller cone arranged to have a cone separation angle between about 145 degrees and about 166 degrees. In some embodiments, the two-cone drill bit has a plurality of cutting elements arranged on the roller cones such that a bottom hole coverage greater than about 17 percent is achieved per revolution of the two-cone drill bit.Type: ApplicationFiled: January 7, 2008Publication date: May 1, 2008Applicant: SMITH INTERNATIONAL, INC.Inventors: Mohammed Boudrare, Prabhakaran Centala
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Publication number: 20070062736Abstract: The invention provides an improved drill bit and a method for designing thereof. The drill bit includes a bit body, a journal depending from the bit body, and a disc rotatably mounted on the journal. The disc of the drill bit has PDC cutting elements disposed on it. Also provided is an improved cutting structure for the discs of the drill bit. The cutting structure includes a portion that is comprised from PDC.Type: ApplicationFiled: September 21, 2005Publication date: March 22, 2007Applicant: Smith International, Inc.Inventors: Peter Cariveau, Prabhakaran Centala, Zhehua Zhang
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Publication number: 20060054361Abstract: A two-cone drill bit that exhibits improved stability. In one embodiment, the two-cone drill bit has a first and a second roller cone arranged to have a cone separation angle between about 145 degrees and about 166 degrees. In some embodiments, the two-cone drill bit has a plurality of cutting elements arranged on the roller cones such that a bottom hole coverage greater than about 17 percent is achieved per revolution of the two-cone drill bit.Type: ApplicationFiled: September 10, 2004Publication date: March 16, 2006Inventors: Mohammed Boudrare, Prabhakaran Centala
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Publication number: 20060054357Abstract: A two-cone drill bit with a hydraulic arrangement that can be used for one or more of the following: cleaning roller cones, impinging on a hole bottom, or inducing a helical flow field. A two-cone drill bit having a bit body formed from two leg sections and two spacing members. Methods of manufacturing a two-cone drill bit. Methods of improving hydraulics of a two-cone drill bit.Type: ApplicationFiled: September 10, 2004Publication date: March 16, 2006Inventors: Prabhakaran Centala, James Larsen, Mohammed Boudrare
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Publication number: 20060011388Abstract: A cutting element is disclosed having multiple cutting extensions extending from the base portion and separated by valleys. The cutting extensions of the cutting element include both crested and rounded shapes. The cutting extensions may differ in extension height, shape, extension angle, cant angle, and crest angle in other characteristics such as in material properties such as wear resistance, hardness and fracture toughness. The cutting elements have particular, but not exclusive, application in the nose portion of the cone cutters of a rolling cone bit.Type: ApplicationFiled: June 13, 2005Publication date: January 19, 2006Inventors: Mohammed Boudrare, Prabhakaran Centala, Scott McDonough, Zhou Yong, Vincent Shotton
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Publication number: 20050015230Abstract: A method for designing a bit for boring earth formations includes defining parameters for a calculation, where the parameters relate to a geometry of the bit, calculating to determine interference between the bit and the earth formations, obtaining vertical displacements with respect to a bit revolution based on the interference between the bit and the earth formations and applying a criterion to the vertical displacements to evaluate bit performance.Type: ApplicationFiled: July 13, 2004Publication date: January 20, 2005Inventors: Prabhakaran Centala, Mohamed Boudrare, Sujian Huang
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Patent number: D1068885Type: GrantFiled: July 29, 2022Date of Patent: April 1, 2025Assignee: National Oilwell Varco, L.P.Inventor: Prabhakaran Centala
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Patent number: D1068886Type: GrantFiled: July 29, 2022Date of Patent: April 1, 2025Assignee: NATIONAL OILWELL VARCO, L.P.Inventor: Prabhakaran Centala
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Patent number: D1094487Type: GrantFiled: May 11, 2023Date of Patent: September 23, 2025Assignee: NATIONAL OILWELL VARCO, L.P.Inventor: Prabhakaran Centala