Patents by Inventor Lalitha Venkataramanan

Lalitha Venkataramanan 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).

  • Patent number: 7305306
    Abstract: Methods and systems are provided for downhole analysis of formation fluids by deriving fluid properties and associated uncertainty in the predicted fluid properties based on downhole data, and generating answer products of interest based on differences in the fluid properties. Measured data are used to compute levels of contamination in downhole fluids using an oil-base mud contamination monitoring (OCM) algorithm. Fluid properties are predicted for the fluids and uncertainties in predicted fluid properties are derived. A statistical framework is provided for comparing the fluids to generate, in real-time, robust answer products relating to the formation fluids and reservoirs thereof. Systematic errors in measured data are reduced or eliminated by preferred sampling procedures.
    Type: Grant
    Filed: May 19, 2005
    Date of Patent: December 4, 2007
    Assignee: Schlumberger Technology Corporation
    Inventors: Lalitha Venkataramanan, Go Fujisawa, Bhavani Raghuraman, Oliver Mullins, Andrew Carnegie, Ricardo Vasques, Chengli Dong, Kai Hsu, Michael O'Keefe, Henri-Pierre Valero
  • Patent number: 7231305
    Abstract: A method for determining the bubble point pressure and the true flow rate of a fluid in a flow line of a flowing well is provided, wherein the method includes modifying fluid pressure in a predetermined region of the flow line, generating pressure data responsive to the flow line, obtaining apparent flow rate data responsive to the pressure data, examining the apparent flow rate data to identify a discontinuity in the apparent flow rate data and generating true flow rate data responsive to the discontinuity.
    Type: Grant
    Filed: August 5, 2004
    Date of Patent: June 12, 2007
    Assignee: Schlumberger Technology Corporation
    Inventors: Kenneth Edward Stephenson, Lalitha Venkataramanan
  • Publication number: 20060155472
    Abstract: Methods and systems are provided for downhole analysis of formation fluids by deriving differential fluid properties and associated uncertainty in the predicted fluid properties based on downhole data less sensitive to systematic errors in measurements, and generating answer products of interest based on the differences in the fluid properties. Measured data are used to compute levels of contamination in downhole fluids using, for example, an oil-base mud contamination monitoring (OCM) algorithm. Fluid properties are predicted for the fluids and uncertainties in predicted fluid properties are derived. A statistical framework is provided for comparing the fluids to generate robust, real-time answer products relating to the formation fluids and reservoirs thereof. Systematic errors in measured data are reduced or eliminated by preferred sampling procedures.
    Type: Application
    Filed: August 18, 2005
    Publication date: July 13, 2006
    Inventors: Lalitha Venkataramanan, Oliver Mullins, Ricardo Vasques
  • Publication number: 20060155474
    Abstract: Methods and systems are provided for downhole analysis of formation fluids by deriving fluid properties and associated uncertainty in the predicted fluid properties based on downhole data, and generating answer products of interest based on differences in the fluid properties. Measured data are used to compute levels of contamination in downhole fluids using an oil-base mud contamination monitoring (OCM) algorithm. Fluid properties are predicted for the fluids and uncertainties in predicted fluid properties are derived. A statistical framework is provided for comparing the fluids to generate, in real-time, robust answer products relating to the formation fluids and reservoirs thereof. Systematic errors in measured data are reduced or eliminated by preferred sampling procedures.
    Type: Application
    Filed: May 19, 2005
    Publication date: July 13, 2006
    Inventors: Lalitha Venkataramanan, Go Fujisawa, Bhavani Raghuraman, Oliver Mullins, Andrew Carnegie, Ricardo Vasques, Chengli Dong, Kai Hsu, Michael O'Keefe, Henri-Pierre Valero
  • Publication number: 20050149264
    Abstract: A distributed temperature sensor is deployed in a wellbore and is functionally connected to a processor. The processor receives the data from the distributed temperature sensor and automatically processes the data to highlight valuable information to the user relating to the relevant well, completion, or reservoir. In one embodiment, the distributed temperature sensor and processor are utilized in a well containing a gas-lift system, wherein the processor highlights valuable information to the user pertaining to the gas-lift system. A well model enabled by the processor enables the determination of a produced fluid flow rate in the well having a gas lift system. Temperatures are measured within the well to obtain a temperature profile, and this profile is processed according to the well model. The well model relates thermal characteristics, e.g. thermal decay and/or amplitude of a thermal discontinuity at an injection point, to flow rate.
    Type: Application
    Filed: October 13, 2004
    Publication date: July 7, 2005
    Applicant: Schlumberger Technology Corporation
    Inventors: Jeffrey Tarvin, Lalitha Venkataramanan, Thomas White, George Brown
  • Patent number: 6891369
    Abstract: The present invention discloses a diffusion edited pulse technique that allows information about a fluid to be extracted, comprising: a) obtaining a fluid sample; b) generating a sequence of magnetic field pulses in the fluid, the sequence comprising an initial magnetic field pulse, a first portion that follows the initial magnetic field pulse, and a second portion that follows the first portion; c) detecting magnetic resonance signals using the second portion of the sequence; d) modifying the first portion of the sequence, and repeating steps (b) and (c); and e) extracting information about the fluid by determining relaxation and diffusion characteristics and their correlation based on the signals detected in steps (c) and (d). Also disclosed is a logging tool equipped with a processor to implement the diffusion edited pulse technique.
    Type: Grant
    Filed: December 13, 2002
    Date of Patent: May 10, 2005
    Assignee: Schlumberger Technology Corporation
    Inventors: Martin D. Hurlimann, Charles Flaum, Mark Flaum, Lalitha Venkataramanan, Robert L. Kleinberg
  • Patent number: 6883702
    Abstract: The present invention relates to a method and apparatus for determining the wettability of a porous media, such as bone, plant, food, wood or molecular sieves, etc., having two or more fluids. The method of the present invention correlates a diffusion-relaxation calibration function representative of at least one fluid in the porous media with a 2-D function developed using diffusion-editing to determine wettability of the porous media.
    Type: Grant
    Filed: March 7, 2003
    Date of Patent: April 26, 2005
    Assignee: Schlumberger Technology Corporation
    Inventors: Martin D. Hurlimann, Lalitha Venkataramanan, Christian Straley
  • Publication number: 20050033530
    Abstract: A method for determining the bubble point pressure and the true flow rate of a fluid in a flow line of a flowing well is provided, wherein the method includes modifying fluid pressure in a predetermined region of the flow line, generating pressure data responsive to the flow line, obtaining apparent flow rate data responsive to the pressure data, examining the apparent flow rate data to identify a discontinuity in the apparent flow rate data and generating true flow rate data responsive to the discontinuity.
    Type: Application
    Filed: August 5, 2004
    Publication date: February 10, 2005
    Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: Kenneth Stephenson, Lalitha Venkataramanan
  • Publication number: 20040248314
    Abstract: A preferred method for determining the flow fraction of a mixture of water, gas and oil in a hydrocarbon reservoir includes measuring pressure and density of the mixture over time, determining a function which approximates a relationship between the density and pressure measurements, calculating a derivative of the function over time, and determining flow fraction based, in part, on the derivative. Preferably, transient data points are eliminated and the remaining set of data points are weight averaged to improve signal to noise ratio. Bubble point pressure, bubble point density and molecular weight and density of the liquid portion of the mixture are also used in the determination.
    Type: Application
    Filed: June 4, 2003
    Publication date: December 9, 2004
    Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: Kenneth E. Stephenson, Lalitha Venkataramanan
  • Publication number: 20040010374
    Abstract: In accordance with an embodiment of the present invention, a method of processing large volumes of data to allow for real-time reservoir management is disclosed, comprising: a) acquiring a first data series from a first reservoir sensor; b) establishing a set of criteria based on reservoir management objectives, sensor characteristics, sensor location, nature of the reservoir, and data storage optimization, etc.; c) identifying one or more subsets of the first data series meeting at least one of the criteria; and optionally d) generating one or more second data series based on at least one of the subsets. This methodology may be repeated for numerous reservoir sensors. This methodology allows for intelligent evaluation of sensor data by using carefully established criteria to intelligently select one or more subsets of data. In an alternative embodiment, sensor data from one or more sensors may be evaluated while processing data from a different sensor.
    Type: Application
    Filed: May 20, 2003
    Publication date: January 15, 2004
    Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: Bhavani Raghuraman, Terizhandur S. Ramakrishnan, Kenneth E. Stephenson, Lalitha Venkataramanan, Jose Navarro
  • Publication number: 20030178994
    Abstract: The present invention discloses a diffusion edited pulse technique that allows information about a fluid to be extracted, comprising: a) obtaining a fluid sample; b) generating a sequence of magnetic field pulses in the fluid, the sequence comprising an initial magnetic field pulse, a first portion that follows the initial magnetic field pulse, and a second portion that follows the first portion; c) detecting magnetic resonance signals using the second portion of the sequence; d) modifying the first portion of the sequence, and repeating steps (b) and (c); and e) extracting information about the fluid by determining relaxation and diffusion characteristics and their correlation based on the signals detected in steps (c) and (d). Also disclosed is a logging tool equipped with a processor to implement the diffusion edited pulse technique.
    Type: Application
    Filed: December 13, 2002
    Publication date: September 25, 2003
    Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION,
    Inventors: Martin D. Hurlimann, Charles Flaum, Mark Flaum, Lalitha Venkataramanan, Robert L. Kleinberg
  • Publication number: 20030169040
    Abstract: The present invention relates to a method and apparatus for determining the wettability of a porous media, such as bone, plant, food, wood or molecular sieves, etc., having two or more fluids. The method of the present invention correlates a diffusion-relaxation calibration function representative of at least one fluid in the porous media with a 2-D function developed using diffusion-editing to determine wettability of the porous media.
    Type: Application
    Filed: March 7, 2003
    Publication date: September 11, 2003
    Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: Martin D. Hurlimann, Lalitha Venkataramanan, Christian Straley
  • Patent number: 6597171
    Abstract: Nuclear magnetic resonance methods for extracting information about a fluid in a rock are described. A system of nuclear spins in the fluid are prepared in a driven equilibrium, and a series of magnetic resonance signals generated from the fluid. The series of magnetic resonance signals is detected and analyzed to extract information about the fluid in the rock.
    Type: Grant
    Filed: July 20, 2001
    Date of Patent: July 22, 2003
    Assignee: Schlumberger Technology Corporation
    Inventors: Martin D. Hurlimann, Olivier J. Terneaud, Denise Freed, Ulrich Scheven, Lalitha Venkataramanan
  • Patent number: 6570382
    Abstract: NMR methods for extracting information about a fluid in rock and logging apparatuses for implementing such methods in a borehole environment are provided. The methods involve generating at least two different magnetic field pulse sequences. The magnetic field pulse sequences include a first portion and a second portion. A magnetic field pulse sequence is generated, and magnetic resonance signals are detected using the second portion of the sequence. The first portion of the sequence is modified, and again the sequence generated and magnetic resonance signals detected using the second portion. The magnetic resonance signals are analyzed, and information about, for example, diffusion coefficient, viscosity, composition, saturation in a rock, pore size, pore geometry and the like, extracted from the analyzed signals.
    Type: Grant
    Filed: November 28, 2000
    Date of Patent: May 27, 2003
    Assignee: Schlumberger Technology Corporation
    Inventors: Martin D. Hurlimann, Charles Flaum, Mark Flaum, Lalitha Venkataramanan
  • Patent number: 6462542
    Abstract: Nuclear magnetic resonance measurements on a fluid in a rock and methods of analyzing nuclear magnetic resonance data are described. At least one nuclear magnetic resonance measurement is performed, and nuclear magnetic resonance data from each of the measurements are acquired. The data are compressed and analyzed to extract information about the fluid in the rock.
    Type: Grant
    Filed: July 20, 2001
    Date of Patent: October 8, 2002
    Assignee: Schlumberger Technology Corporation
    Inventors: Lalitha Venkataramanan, Yi-Qiao Song, Martin D. Hurlimann
  • Publication number: 20020105326
    Abstract: Nuclear magnetic resonance methods for extracting information about a fluid in a rock are described. A system of nuclear spins in the fluid are prepared in a driven equilibrium, and a series of magnetic resonance signals generated from the fluid. The series of magnetic resonance signals is detected and analyzed to extract information about the fluid in the rock.
    Type: Application
    Filed: July 20, 2001
    Publication date: August 8, 2002
    Inventors: Martin D. Hurlimann, Olivier J. Terneaud, Denise Freed, Ulrich Scheven, Lalitha Venkataramanan
  • Publication number: 20020067164
    Abstract: Nuclear magnetic resonance measurements on a fluid in a rock and methods of analyzing nuclear magnetic resonance data are described. At least one nuclear magnetic resonance measurement is performed, and nuclear magnetic resonance data from each of the measurements are acquired. The data are compressed and analyzed to extract information about the fluid in the rock.
    Type: Application
    Filed: July 20, 2001
    Publication date: June 6, 2002
    Inventors: Lalitha Venkataramanan, Yi-Qiao Song, Martin D. Hurlimann