Patents by Inventor Raghu Madhavan
Raghu Madhavan 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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Patent number: 10233934Abstract: Fracture-resistant and self-lubricating wear surfaces are provided. In an implementation, a machine surface that is subject to wear is coated with or is constructed of a metallic nanostructure to resist the wear and to provide fracture-resistant hardness, built-in lubrication, and thermal conductivity for heat-sinking friction. The metallic nanostructured surface may be used, for example, on a face seal, bushing, bearing, thrust member, or hydraulic flow passage of an electric submersible pump. In an implementation, the metallic nanostructured surface is a nanocrystalline alloy including nanograin twins of a body-centered cubic (BCC), face-centered cubic (FCC), or hexagonal closest packed (HCP) metal. The nanostructured alloy may include atoms of copper, silver, gold, iron, nickel, palladium, platinum, rhodium, beryllium, magnesium, titanium, zirconium, or cobalt, and may provide more hardness and lubricity than diamond-like carbon coatings or carbides.Type: GrantFiled: August 3, 2014Date of Patent: March 19, 2019Assignee: SCHLUMBERGER TECHNOLOGY CORPORATIONInventors: Manuel P. Marya, Raghu Madhavan, Indranil Roy
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Publication number: 20160177959Abstract: Fracture-resistant and self-lubricating wear surfaces are provided. In an implementation, a machine surface that is subject to wear is coated with or is constructed of a metallic nanostructure to resist the wear and to provide fracture-resistant hardness, built-in lubrication, and thermal conductivity for heat-sinking friction. The metallic nanostructured surface may be used, for example, on a face seal, bushing, bearing, thrust member, or hydraulic flow passage of an electric submersible pump. In an implementation, the metallic nanostructured surface is a nanocrystalline alloy including nanograin twins of a body-centered cubic (BCC), face-centered cubic (FCC), or hexagonal closest packed (HCP) metal. The nanostructured alloy may include atoms of copper, silver, gold, iron, nickel, palladium, platinum, rhodium, beryllium, magnesium, titanium, zirconium, or cobalt, and may provide more hardness and lubricity than diamond-like carbon coatings or carbides.Type: ApplicationFiled: August 3, 2014Publication date: June 23, 2016Inventors: Manuel P. Marya, Raghu Madhavan, Indranil Roy
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Patent number: 9366092Abstract: A system for use in a drilling operation that includes uphole electronic equipment and a drill string suspended in an earth borehole, a section of wired drill pipe that is part of a communication link between a downhole tool and the uphole electronic equipment, an interface for communicating between the section of wired drill pipe and a communication source/destination. The system includes a housing having a generally cylindrical outer shape which has a passage there through. The housing has a WDP end connectable to the section of wired drill pipe and a further end connectable to the communication source/destination. The system also includes a WDP circuit module disposed within the housing. The WDP circuit module electrically coupleable with the wired drill pipe section. The system includes a further circuit module, disposed within the housing, which is electrically coupled with the WDP circuit module and electrically coupleable with the communication source/destination.Type: GrantFiled: August 3, 2006Date of Patent: June 14, 2016Assignee: INTELLISERV, LLCInventors: Remi Hutin, David Santoso, Lise Hvatum, Christopher P. Reed, Raghu Madhavan, Jean-Marc Follini
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Publication number: 20150325990Abstract: A method for making a conduit for transmitting signals along its length includes forming one or more grooves in at least one of the inner and outer walls of a tubular body that extend substantially to a communicative coupler, and securing one or more conductive wires within the one or more grooves. A conduit for transmitting signals along its length in a borehole environment includes one or more conductive wires extending through and being secured within one or more grooves of a tubular body, the one or more conductive wires in signal communication with a communicative coupler so as to establish one or more wired links. The conduit may include a means for securing the one or more conductive wires within the one or more grooves.Type: ApplicationFiled: July 23, 2015Publication date: November 12, 2015Applicant: INTELLISERV, LLCInventors: Raghu MADHAVAN, Bruce W. BOYLE, Brian CLARK
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Patent number: 9157313Abstract: A drilling system comprises a drillstring including a dill bit, a bottomhole assembly coupled to the drill bit, and a plurality of interconnected tubular members coupled to the bottomhole assembly. A first tubular member includes a communication link having a first annular inductive coupler element disposed in an annular recess in a first end, a second annular inductive coupler element disposed in an annular recess in a second end, and a cable coupling the first annular inductive coupler element to the second annular inductive coupler element. In addition, the drilling system comprises a first signal level determination unit disposed in the drillstring and configured to determine a level of a first signal communicated from the second inductive coupler element. Further, the drilling system comprises an axial load determination unit configured to determine an axial load at the first signal level determination unit based on the level of the first signal.Type: GrantFiled: June 1, 2012Date of Patent: October 13, 2015Assignee: INTELLISERV, LLCInventors: Raghu Madhavan, Mark Sherman
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Patent number: 9121962Abstract: A method for making a conduit for transmitting signals along its length includes forming one or more grooves in at least one of the inner and outer walls of a tubular body that extend substantially to a communicative coupler, and securing one or more conductive wires within the one or more grooves. A conduit for transmitting signals along its length in a borehole environment includes one or more conductive wires extending through and being secured within one or more grooves of a tubular body, the one or more conductive wires in signal communication with a communicative coupler so as to establish one or more wired links. The conduit may include a means for securing the one or more conductive wires within the one or more grooves.Type: GrantFiled: December 31, 2012Date of Patent: September 1, 2015Assignee: Intelliserv, LLCInventors: Raghu Madhavan, Bruce W. Boyle, Brian Clark
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Patent number: 9109439Abstract: A hybrid telemetry system for passing signals between a surface control unit and a downhole tool is provided. The downhole tool is deployed via a drill string into a wellbore penetrating a subterranean formation. The hybrid telemetry system includes an uphole connector, a downhole connector, and a cable operatively connecting the uphole and downhole connectors. The uphole connector is operatively connectable to a drill string telemetry system for communication therewith. The downhole connector is operatively connectable to the downhole tool for communication therewith.Type: GrantFiled: December 29, 2006Date of Patent: August 18, 2015Assignee: INTELLISERV, LLCInventors: Jean-Michel Hache, Remi Hutin, Raghu Madhavan, David Santoso
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Patent number: 8810428Abstract: A rotary coupler for transferring electrical power and data between members is presented wherein the coupler has a first member having an internal surface, a first inductor positioned on the internal surface, a second member and a second inductor carried on a portion of the second member and positioned internal of the first inductor, wherein one of the inductors rotates relative to the other inductor.Type: GrantFiled: September 2, 2008Date of Patent: August 19, 2014Assignee: Schlumberger Technology CorporationInventors: Raghu Madhavan, Frederic Latrille
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Patent number: 8614273Abstract: A seal member includes a hydrogenated acrylonitrile-butadiene rubber (HNBR) and carbon nanofibers. The seal member has a number of cycles to fracture of 7000 or more when subjected to a tensile fatigue test at a temperature of 70° C., a maximum tensile stress of 4 N/mm, and a frequency of 1 Hz. The seal member exhibits excellent abrasion resistance.Type: GrantFiled: December 28, 2009Date of Patent: December 24, 2013Assignees: Nissin Kogyo Co., Ltd., Schlumberger Technology Corporation, Shinshu UniversityInventors: Toru Noguchi, Hiroyuki Ueki, Shigeki Inukai, Masaei Ito, Raghu Madhavan, Morinobu Endo, Satoshi Iinou
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Publication number: 20130319768Abstract: A drilling system comprises a drillstring including a dill bit, a bottomhole assembly coupled to the drill bit, and a plurality of interconnected tubular members coupled to the bottomhole assembly. A first tubular member includes a communication link having a first annular inductive coupler element disposed in an annular recess in a first end, a second annular inductive coupler element disposed in an annular recess in a second end, and a cable coupling the first annular inductive coupler element to the second annular inductive coupler element. In addition, the drilling system comprises a first signal level determination unit disposed in the drillstring and configured to determine a level of a first signal communicated from the second inductive coupler element. Further, the drilling system comprises an axial load determination unit configured to determine an axial load at the first signal level determination unit based on the level of the first signal.Type: ApplicationFiled: June 1, 2012Publication date: December 5, 2013Applicant: Intelliserv, LLCInventors: Raghu Madhavan, Mark Sherman
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Patent number: 8403332Abstract: The seal member includes a tetrafluoroethylene-propylene copolymer (FEPM) and carbon nanofibers. The seal member has a number of cycles to fracture of 10 or more when subjected to a tension fatigue test at a temperature of 150° C., a maximum tensile stress of 2 N/mm, and a frequency of 1 Hz. The seal member exhibits excellent heat resistance and abrasion resistance.Type: GrantFiled: December 28, 2009Date of Patent: March 26, 2013Assignees: Nissan Kogyo Co., Ltd, Schlumberger Technology Corporation, Shinshu UniversityInventors: Toru Noguchi, Hiroyuki Ueki, Shigeki Inukai, Masaei Ito, Raghu Madhavan, Morinobu Endo, Satoshi Iinou
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Patent number: 8398301Abstract: Apparatus for determining downhole fluid temperatures are described. An example apparatus for measuring a temperature of a downhole fluid includes a sensing element for measuring a physical or chemical property of the downhole fluid, and a plurality of electrical connections to enable the sensing element to measure the chemical or physical property and provide an output signal representative of the chemical or physical property, wherein at least one of the electrical connections is configured to function as a thermocouple to sense a temperature of the downhole fluid.Type: GrantFiled: April 20, 2010Date of Patent: March 19, 2013Assignee: Schlumberger Technology CorporationInventors: Raghu Madhavan, Michael Stangeland
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Patent number: 8344905Abstract: An expandable tubular sleeve having utility for lining a downhole tubular member includes a tubular body having a portion that is predisposed to initiate expansion thereof under the application of internal fluid pressure. The predisposed portion of the body may be a plastically-deformed portion formed, e.g., by application of mechanical force to a wall of the body. The predisposed portion of the body may be defined by a portion of the body having reduced wall thickness. The reduced wall thickness may be achieved, e.g., by reinforcing the wall thickness everywhere except the predisposed portion. The predisposed portion of the body may be formed by modifying the material properties of the body, e.g., by localized heat treatment. The sleeve and related apparatuses and methods are useful for securing and protecting a cable having one or more insulated conductive wires for transmission of signals between locations downhole and at the surface.Type: GrantFiled: July 14, 2008Date of Patent: January 1, 2013Assignee: Intelliserv, LLCInventors: Raghu Madhavan, Bruce W. Boyle, Brian Clark
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Patent number: 8322196Abstract: Vibrating wire viscometers are described. Some example vibrating wire viscometer housings include a flowline through the housing to expose a first wire to a downhole fluid, a cavity in the housing to hold a magnet and to conduct one or more additional wires from the flowline to a signal generator, first and second electrically conductive posts mechanically coupled to the housing to hold the first wire in tension within the flowline, and a seal mechanically coupled to the housing to prevent access to the magnet by the downhole fluid.Type: GrantFiled: August 2, 2009Date of Patent: December 4, 2012Assignee: Schlumberger Technology CorporationInventors: Raghu Madhavan, Yu Hatori, Mami Nishida, Sophie Nazik Godefroy, Michael Stangeland, Go Fujisawa
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Patent number: 8164476Abstract: A hybrid telemetry system for passing signals between a surface control unit and a downhole tool is provided. The downhole tool is deployed via a drill string into a wellbore penetrating a subterranean formation. The hybrid telemetry system includes an uphole connector, a downhole connector, and a cable operatively connecting the uphole and downhole connectors. The uphole connector is operatively connectable to a drill string telemetry system for communication therewith. The downhole connector is operatively connectable to the downhole tool for communication therewith.Type: GrantFiled: September 1, 2010Date of Patent: April 24, 2012Assignee: IntelliServ, LLCInventors: Jean-Michel Hache, Remi Hutin, Raghu Madhavan, David Santoso
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Patent number: 8120508Abstract: A cable link may include a first link connector in signal communication with at least one sensor in a drill string and coupled to the drill string, a second link connector spaced apart from the first link connector and in signal communication with a telemetry system, the second connector link coupled to the drill string, and a linking cable having signal connectors at each end thereof, the linking cable having at least one of an electrical conductor and an optical fiber therein, the signal connectors each configured to latch proximate a respective one of the first and second link connector.Type: GrantFiled: December 29, 2006Date of Patent: February 21, 2012Assignee: IntelliServ, LLCInventors: Raghu Madhavan, David Santoso, Lise Hvatum
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Patent number: 8072347Abstract: A method for determining electrical condition of a wired drill pipe includes inducing an electromagnetic field in at least one joint of wired drill pipe. Voltages induced by electrical current flowing in at least one electrical conductor in the at least one wired drill pipe joint are detected. The electrical current is induced by the induced electromagnetic field. The electrical condition is determined from the detected voltages.Type: GrantFiled: December 29, 2006Date of Patent: December 6, 2011Assignee: Intelliserv, LLC.Inventors: David Santoso, Dudi Rendusara, Hiroshi Nakajima, Kanu Chadha, Raghu Madhavan, Lise Hvatum
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Publication number: 20110252879Abstract: Apparatus for determining downhole fluid temperatures are described. An example apparatus for measuring a temperature of a downhole fluid includes a sensing element for measuring a physical or chemical property of the downhole fluid, and a plurality of electrical connections to enable the sensing element to measure the chemical or physical property and provide an output signal representative of the chemical or physical property, wherein at least one of the electrical connections is configured to function as a thermocouple to sense a temperature of the downhole fluid.Type: ApplicationFiled: April 20, 2010Publication date: October 20, 2011Applicant: SCHLUMBERGER TECHNOLOGY CORPORATIONInventors: RAGHU MADHAVAN, MICHAEL STANGELAND
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Publication number: 20110156355Abstract: A seal member includes a hydrogenated acrylonitrile-butadiene rubber (HNBR) and carbon nanofibers. The seal member has a number of cycles to fracture of 7000 or more when subjected to a tensile fatigue test at a temperature of 70° C., a maximum tensile stress of 4 N/mm, and a frequency of 1 Hz. The seal member exhibits excellent abrasion resistance.Type: ApplicationFiled: December 28, 2009Publication date: June 30, 2011Applicants: NISSIN KOGYO CO., LTD, SCHLUMBERGER TECHNOLOGY CORPORATION, SHINSHU UNIVERSITY, MEFS KABUSHIKI KAISHAInventors: Toru NOGUCHI, Hiroyuki UEKI, Shigeki INUKAI, Masaei ITO, Raghu MADHAVAN, Morinobu ENDO, Satoshi IINOU
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Publication number: 20110156357Abstract: A dynamic seal member includes a ternary fluoroelastomer (FKM) and carbon nanofibers. The carbon nanofibers are carbon nanofibers having an average diameter of 10 to 20 nm, or carbon nanofibers having an average diameter of 60 to 110 nm and subjected to a low-temperature heat treatment. The carbon nanofibers having an average diameter of 60 to 110 nm and subjected to the low-temperature heat treatment have a ratio (D/G) of a peak intensity D at around 1300 cm?1 to a peak intensity G at around 1600 cm?1 measured by Raman scattering spectroscopy of more than 0.9 and less than 1.6. The dynamic seal member has a number of cycles to fracture of 10 or more when subjected to a tension fatigue test at a temperature of 200° C., a maximum tensile stress of 2.5 N/mm, and a frequency of 1 Hz. The dynamic seal member exhibits excellent heat resistance and abrasion resistance.Type: ApplicationFiled: December 28, 2009Publication date: June 30, 2011Applicants: NISSIN KOGYO CO., LTD., SCHLUMBERGER TECHNOLOGY CORPORATION, SHINSHU UNIVERSITY, MEFS KABUSHIKI KAISHAInventors: Toru NOGUCHI, Hiroyuki UEKI, Shigeki INUKAI, Masaei ITO, Raghu MADHAVAN, Morinobu ENDO, Satoshi IINOU