Patents by Inventor Terizhandur S. Ramakrishnan

Terizhandur S. Ramakrishnan 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: 20160145977
    Abstract: Methods are provided for adaptive optimization of enhanced oil recovery project performance under uncertainty. Predictive physics-based reservoir simulation is used to estimate performance of the project. Input parameters of the model are divided into control variables and uncertain variables. The reservoir model is optimized to obtain values of control variables maximizing mean value of a chosen performance metric under initial uncertainty of formation and fluid properties. An efficient frontier can characterize dependence between the optimized mean value of the performance metric and its uncertainty expressed by the standard deviation. Global sensitivity analysis (GSA) is then applied to quantify and rank contributions from uncertain input parameters to the standard deviation of the optimized values of the performance metric. Additional measurements can be performed to reduce uncertainty in the high-ranking parameters.
    Type: Application
    Filed: November 23, 2015
    Publication date: May 26, 2016
    Inventors: Nikita Chugunov, Terizhandur S. Ramakrishnan, Pierre Barrat-Charlaix
  • Patent number: 9312557
    Abstract: A rechargeable power system comprising: a drill string configured to operate in a well bore, the drill string comprising: a fuel cell system; a generator in electrical communication with the fuel cell system; a turbine, configured to rotate due to an impingement of drilling mud on one or more turbine blades, the turbine in operable communication with the generator; and where the fuel cell system is configured to provide power at least when drilling mud is not circulating in the well bore, and further configured to be recharged by the generator when drilling mud is circulating in the well bore. A method for operating a rechargeable downhole fuel cell. The method comprises: monitoring a fluid supply pressure; determining whether the fluid supply pressure is below a threshold value; and stopping a fuel cell discharge if the fluid supply pressure is below the threshold value.
    Type: Grant
    Filed: May 11, 2005
    Date of Patent: April 12, 2016
    Assignee: Schlumberger Technology Corporation
    Inventors: Wenlin Zhang, Terizhandur S. Ramakrishnan, Joseph Walter, Albert Perez, Jr.
  • Patent number: 9291046
    Abstract: A well completion and related method are provided for formations susceptible to simultaneous production of oil and water. In one embodiment, two closely spaced, preferably horizontal wellbores are drilled from a single well into the reservoir. The reservoir rock surrounding one leg (typically the upper leg) is chemically treated to make it hydrophobic, whereas the reservoir rock surrounding the other leg is chemically treated to make it hydrophilic. Separate production tubing and a dual completion is installed in order to enable independent flow from each leg. Drawdown pressures in both legs are controlled to be sufficiently close to each other such that only oil flows into one leg and only water into the other. The water produced is re-injected downhole or brought to the surface.
    Type: Grant
    Filed: July 27, 2011
    Date of Patent: March 22, 2016
    Assignee: Schlumberger Technology Corporation
    Inventors: Terizhandur S. Ramakrishnan, Paul S. Hammond, John M. Cook
  • Publication number: 20160040531
    Abstract: A formation is characterized by generating a model of the formation that characterizes the formation in a manner consistent with all measurements, thereby permitting a computation or prediction of how the formation will respond to disturbances or stimuli such as fluid injection for production, carbon-dioxide injection for sequestration, current injection, etc. The formation is described with a fundamental set of microscopic parameters such that quantities relevant to petrophysical response at a continuum or macroscopic level can be derived from them. Values for various formation parameters are determined, as are values for various field variables.
    Type: Application
    Filed: October 4, 2013
    Publication date: February 11, 2016
    Inventors: Terizhandur S. RAMAKRISHNAN, Yusuf Bilgin ALTUNDAS, Nikita CHUGUNOV, Romain DE LOUBENS, Francois B. FAYARD
  • Patent number: 9235838
    Abstract: A flow control apparatus for controlling fluid flow in a petroleum reservoir. The flow control apparatus has a flow control mechanism, a controller operable to control the flow control mechanism to adjust fluid flow through the flow control mechanism, the controller comprising a processor operable to execute according to a control algorithm, and a non-volatile memory connected to the controller. The non-volatile memory includes instructions to cause the controller to execute an authentication mechanism operable to authenticate a control computer and to prevent operation of the controller until the authentication mechanism authenticates the control computer.
    Type: Grant
    Filed: June 7, 2007
    Date of Patent: January 12, 2016
    Assignee: Schlumberger Technology Corporation
    Inventors: Paul D. Gerardi, Valery Polyakov, Terizhandur S. Ramakrishnan, Bertrand du Castel
  • Publication number: 20150293007
    Abstract: Methods and apparatus are disclosed for measuring the permeability and/or porosity of ultra-low permeable rock samples. In some embodiments, the methods utilize fluid pressure perturbation.
    Type: Application
    Filed: April 14, 2014
    Publication date: October 15, 2015
    Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: TERIZHANDUR S. RAMAKRISHNAN, MICHAEL SUPP
  • Publication number: 20150293008
    Abstract: Apparatus and calibration methods are disclosed for measuring the permeability and/or porosity of ultra-low permeable rock samples. The apparatus uses a gas source, a sample chamber, chambers of calibrated volume, and pressure measurement devices.
    Type: Application
    Filed: April 14, 2014
    Publication date: October 15, 2015
    Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: TERIZHANDUR S. RAMAKRISHNAN, MICHAEL SUPP
  • Publication number: 20150267521
    Abstract: Measuring a parameter characteristic of a formation in an oil well with a device configured to generate a sensing field within a volume of the formation and cause a flow through the volume in the presence of the sensing field. The device also comprises sensors responsive to changes in the volume, which indicate existent amounts of fluid, such as hydrocarbon and water saturations and irreducible hydrocarbon and water saturations. Measurements may be made before the flow affects the measuring volume and after onset of the flow through the measuring volume.
    Type: Application
    Filed: June 8, 2015
    Publication date: September 24, 2015
    Inventors: Cosan Ayan, Fikri John Kuchuk, Terizhandur S. Ramakrishnan, Thomas J. Neville, Raghu Ramamoorthy, Andrew J. Carnegie
  • Publication number: 20150234069
    Abstract: Methods and systems acquiring acoustic data utilizing a downhole tool conveyed within a borehole extending into a subterranean formation. The downhole tool is in communication with surface equipment disposed at a wellsite surface from which the borehole extends. Techniques involve operating at least one of the downhole tool and the surface equipment to generate a histogram based on the acoustic data, normalizing the histogram, and calculating a vug index based on the normalized histogram and based on a threshold of the normalized histogram. A vug porosity quantity may be determined based on the calculated vug index.
    Type: Application
    Filed: February 16, 2015
    Publication date: August 20, 2015
    Inventors: Terizhandur S. Ramakrishnan, Nadege Bize-Forest, Rodolfo Oliveira, Flora Marques, Austin Boyd, Emmanuel Bize
  • Patent number: 9051822
    Abstract: Measuring a parameter characteristic of a formation in an oil well with a device configured to generate a sensing field within a volume of the formation and cause a flow through the volume in the presence of the sensing field. The device also comprises sensors responsive to changes in the volume, which indicate existent amounts of fluid, such as hydrocarbon and water saturations and irreducible hydrocarbon and water saturations. Measurements may be made before the flow affects the measuring volume and after onset of the flow through the measuring volume.
    Type: Grant
    Filed: April 15, 2009
    Date of Patent: June 9, 2015
    Assignee: Schlumberger Technology Corporation
    Inventors: Cosan Ayan, Fikri John Kuchuk, Terizhandur S. Ramakrishnan, Thomas J. Neville, Raghu Ramamoorthy, Andrew J. Carnegie
  • Publication number: 20150047990
    Abstract: Described herein is an apparatus and methods for characterizing a fluid composition including exposing electrolyte to one fluid mixture, collecting a signal from an electrode in contact with the electrolyte, and simultaneously exposing the electrolyte to a second fluid, collecting a signal from a second electrode in contact with the electrolyte exposed to the second fluid, and comparing the signal difference between the electrodes with the Nerst equation wherein the temperature of the electrolyte is above 488° C. Carbon dioxide, nitrogen, and/or oxygen may be present in the fluid and/or the second fluid.
    Type: Application
    Filed: August 13, 2013
    Publication date: February 19, 2015
    Applicant: Schlumberger Technology Corporation
    Inventors: ALBERT PEREZ, TERIZHANDUR S. RAMAKRISHNAN, WENLIN ZHANG, LI JIANG, ROY KOVELESKI, QUINCY K. ELIAS
  • Publication number: 20150004009
    Abstract: Methods and systems are provided for controlling operational parameters of a CO2 compression surface facility or pipeline in order to maintain a CO2 stream having impurities flowing in the pipeline in a liquid or supercritical phase. Sensors may be provided to sense whether the flow is single-phase or two-phase flow, and feedback provided to adjust the pressure and/or temperature at the pipeline inlet. The system is preferably optimized to limit power consumption and/or cost.
    Type: Application
    Filed: September 17, 2014
    Publication date: January 1, 2015
    Inventors: SANDEEP VERMA, CHARLES S. OAKES, TERIZHANDUR S. RAMAKRISHNAN
  • Patent number: 8919438
    Abstract: A method for evaluating wellbore integrity including introducing a drill to a surface of a casing encompassing an annulus, enclosing the drill in a housing hydraulically isolating the surface, drilling through the casing and into cement surrounding the casing, observing a pressure of the fluid, and using the pressure observation and a drill position to evaluate a presence of a defect and a location of the defect. Apparatus for evaluating wellbore integrity including a probe comprising a drill, wherein the probe is hydraulically isolated from the wellbore, a valve that encompasses the drill, a pressure gauge to measure the pressure of the fluid within the housing, a pressure gauge to measure the pressure in the system outside the housing, and equipment to compare the pressure measurements and the position of the drill and to evaluate a presence and a location of the defect.
    Type: Grant
    Filed: October 20, 2011
    Date of Patent: December 30, 2014
    Assignee: Schlumberger Technology Corporation
    Inventors: Terizhandur S. Ramakrishnan, Nikita Chugunov, Ram Sunder Kalyanaraman
  • Patent number: 8874382
    Abstract: Methods and systems are provided for controlling operational parameters of a CO2 compression surface facility or pipeline in order to maintain a CO2 stream having impurities flowing in the pipeline in a liquid or supercritical phase. Sensors may be provided to sense whether the flow is single-phase or two-phase flow, and feedback provided to adjust the pressure and/or temperature at the pipeline inlet. The system is preferably optimized to limit power consumption and/or cost.
    Type: Grant
    Filed: April 30, 2010
    Date of Patent: October 28, 2014
    Assignee: Schlumberger Technology Corporation
    Inventors: Sandeep Verma, Charles S. Oakes, Terizhandur S. Ramakrishnan
  • Patent number: 8862407
    Abstract: Percolation theory is applied to establish a connection between magnetization decay of nuclear magnetic resonance (NMR) measurements and residual carbon dioxide saturation (Scr). As a result, estimations of Scr are obtained through use of an NMR tool in a formation and appropriate processing. Data may be displayed as a log.
    Type: Grant
    Filed: May 21, 2013
    Date of Patent: October 14, 2014
    Assignee: Schlumberger Technology Corporation
    Inventors: Nikita V. Chugunov, Terizhandur S. Ramakrishnan
  • Publication number: 20140278110
    Abstract: A method, apparatus, and program product utilize global sensitivity analysis (GSA) based on variance decomposition to calculate and apportion the contributions to a total variance of a measurement signal from uncertain input parameters of a subsurface model in connection with designing targeted surveys. Through the use of global sensitivity analysis in this manner, the geometry for a survey may be determined based on a desired target of the design, e.g., based on spatial properties (e.g., reservoir zone of interest) and/or physical properties (e.g., porosity, fluid density, rock physics properties) to select locations (e.g., source-receiver pairs) with greater uncertainty contributions from parameter group(s) of interest.
    Type: Application
    Filed: March 12, 2014
    Publication date: September 18, 2014
    Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: NIKITA CHUGUNOV, TERIZHANDUR S. RAMAKRISHNAN, NICOLAE MOLDOVEANU, AIMÉ FOURNIER, KONSTANTIN S. OSYPOV, YUSUF BILGIN ALTUNDAS
  • Patent number: 8720552
    Abstract: An apparatus and method of measuring a parameter characteristic of a rock formation in an oil well is provided with a device for generating a sensing field within a volume of the rock formation and a device for causing a flow through the volume in the presence of the sensing field, further including sensors responsive to changes in the volume, wherein a sensor response is indicative of the amounts of fluid, particularly hydrocarbon and water saturations and irreducible hydrocarbon and water saturations. Measurements can be made before the flow affects the measuring volume and after onset of the flow through the measuring volume.
    Type: Grant
    Filed: October 3, 2011
    Date of Patent: May 13, 2014
    Assignee: Schlumberger Technology Corporation
    Inventors: Cosan Ayan, Fikri John Kuchuk, Terizhandur S. Ramakrishnan, Thomas J. Neville, Raghu Ramamoorthy, Andrew Carnegie
  • Patent number: 8612193
    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: Grant
    Filed: May 20, 2003
    Date of Patent: December 17, 2013
    Assignee: Schlumberger Technology Center
    Inventors: Bhavani Raghuraman, Terizhandur S. Ramakrishnan, Kenneth E. Stephenson, Lalitha Venkataramanan, Jose Navarro
  • Publication number: 20130297273
    Abstract: A method for characterizing a property of a subterranean formation including collecting well log and seismic data, inverting the data, processing for upscaled petrophysical parameters, constructing a flow model that generates saturation, pressure and temperature, constructing seismic velocity relationships from the results of the flow model, and constructing a seismic model. Some embodiments may form a full waveform model or a ray tracing model. Some embodiments may generate a velocity profile and/or waveforms using the profile. Some embodiments may use the parameters to form a reservoir model or to recover hydrocarbons from the formations. Some embodiments build a reservoir model of CO2 injection or CO2 presence after injection or for simulating CO2 presence in a subterranean formation. Some embodiments may also quantify CO2 properties in the reservoir or predict CO2 profile evolution over time in the reservoir including spatial distribution.
    Type: Application
    Filed: October 28, 2011
    Publication date: November 7, 2013
    Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: Yusuf Altundas, Terizhandur S. Ramakrishnan, Satish C. Singh, Manuel Queiser, Junlun Li
  • Publication number: 20130268202
    Abstract: Percolation theory is applied to establish a connection between magnetization decay of nuclear magnetic resonance (NMR) measurements and residual carbon dioxide saturation (Scr). As a result, estimations of Scr are obtained through use of an NMR tool in a formation and appropriate processing. Data may be displayed as a log.
    Type: Application
    Filed: May 21, 2013
    Publication date: October 10, 2013
    Inventors: Nikita V. Chugunov, Terizhandur S. Ramakrishnan