Patents by Inventor Ravinath Kausik Kadayam Viswanathan

Ravinath Kausik Kadayam Viswanathan 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: 20170343497
    Abstract: Downhole fluid volumes of a geological formation may be estimated using nuclear magnetic resonance (NMR) measurements, even in organic shale reservoirs. Multi-dimensional NMR measurements, such as two-dimensional NMR measurements and/or, in some cases, one or more well-logging measurements relating to total organic carbon may be used to estimate downhole fluid volumes of hydrocarbons such as bitumen, light hydrocarbon, kerogen, and/or water. Having identified the fluid volumes in this manner or any other suitable manner from the NMR measurements, a reservoir producibility index (RPI) may be generated. The downhole fluid volumes and/or the RPI may be output on a well log to enable an operator to make operational and strategic decisions for well production.
    Type: Application
    Filed: May 24, 2017
    Publication date: November 30, 2017
    Inventors: Vivek Anand, Ravinath Kausik Kadayam Viswanathan, Tianmin Jiang, Erik Rylander, Mansoor Ali, Richard E. Lewis
  • Publication number: 20170254736
    Abstract: Methods for analyzing a reservoir in a formation containing hydrocarbon fluid are described. Information characterizing the formation is collected and applied to a formation simulator that is provided with a modified Darcy's law equation that ac counts for at least one of gas adsorption/desorption, various modes of diffusive transport, and non-Darcy flow behavior, and the simulator is used to generate indications of the state of the reservoir and/or the state of production of hydrocarbon fluid from the reservoir. The modified Darcy's law equations are particularly useful in analyzing any type of formation containing any type of hydrocarbon fluid including shale formations containing hydrocarbon gases. According to one embodiment, a dual-porosity shape factor useful in a formation simulator is also provided.
    Type: Application
    Filed: August 12, 2015
    Publication date: September 7, 2017
    Inventors: Wenyue Xu, Mery Diaz Campos, Ravinath Kausik Kadayam Viswanathan
  • Patent number: 9720128
    Abstract: An NMR method and apparatus for analyzing a sample of interest applies a static magnetic field together with RF pulses of oscillating magnetic field across a sample volume that encompasses the sample of interest. The RF pulses are defined by a pulse sequence that includes a plurality of measurement segments configured to characterize a plurality of relaxation parameters related to relaxation of nuclear magnetization of the sample of interest. Signals induced by the RF pulses are detected in order to derive the relaxation parameters. The measurement segments of the pulse sequence include at least one first-type measurement segment configured to characterize relaxation of spin-lattice interaction between nuclei of the sample of interest in a rotating frame (T1?) at a predefined frequency. The T1? parameter can be measured in conjunction with the measurement of other relaxation and/or diffusion parameters as part of multidimensional NMR experiments.
    Type: Grant
    Filed: February 15, 2013
    Date of Patent: August 1, 2017
    Assignee: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: Ravinath Kausik Kadayam Viswanathan, Lukasz Zielinski, Martin D. Hürlimann
  • Patent number: 9720124
    Abstract: Apparatus and methods for characterizing hydrocarbons in a subterranean formation include obtaining a sample of the subterranean formation; measuring, uphole, the porosity of the sample; using a nuclear magnetic resonance (NMR) tool downhole in the borehole, sending NMR pulse sequences configured for formation pore size and measuring NMR signals that characterize the formation at a location in the formation; analyzing the signals to find a gas porosity of the formation at the location; and determining a hydrogen index (HIg) of the subterranean formation from the gas porosity and from the porosity of the sample. The obtained HIg may then be used in conjunction with downhole NMR measurements to find corrected gas porosities at locations of the formation.
    Type: Grant
    Filed: August 9, 2012
    Date of Patent: August 1, 2017
    Assignee: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: Ravinath Kausik Kadayam Viswanathan, Chanh Cao Minh, Ridvan Akkurt, Baarinadh Vissapragada, Yi-Qiao Song, Lukasz Zielinski
  • Publication number: 20160341680
    Abstract: A method for testing an unconventional core sample is provided. The method involves loading the unconventional core sample into a sample holder and introducing fluid into the sample holder at an elevated pressure such that fluid is injected into the internal pore space of the unconventional core sample in order to resaturate the unconventional core sample with the fluid, wherein the fluid is selected from the group including a hydrocarbon fluid and a water-based formation fluid. An apparatus and a system used in combination with the method are also provided.
    Type: Application
    Filed: January 21, 2015
    Publication date: November 24, 2016
    Inventors: Ravinath Kausik Kadayam Viswanathan, Kamilla Fellah, Erik Rylander, Philip M. Singer, Richard E. Lewis
  • Patent number: 9405036
    Abstract: Methods for the determination of the Total Gas in Place (TGiP) in gas-bearing formations are provided. Aspects of the subject disclosure also relate to the determination of the TGiP from nuclear magnetic resonance (NMR) logs alone or in combination other well logs.
    Type: Grant
    Filed: November 5, 2012
    Date of Patent: August 2, 2016
    Assignee: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: Ravinath Kausik Kadayam Viswanathan, Lukasz Zielinski, Robert L. Kleinberg
  • Publication number: 20160138392
    Abstract: Levels of kerogen and bitumen are computed in a sample of rock from DRIFTS measurements on the sample. the DRIFTS spectrum of a rock sample is measured, resulting in an estimate of bitumen and kerogen. Bitumen is then washed from the rock and DRIFTS is re-measured, resulting in an estimate of kerogen. Bitumen quantity is calculated by subtracting the washed sampled results from first DRIFTS measurements.
    Type: Application
    Filed: June 23, 2014
    Publication date: May 19, 2016
    Inventors: Andrew Emil Pomerantz, Robert Leonard Kleinberg, Ravinath Kausik Kadayam Viswanathan, Paul Ryan Craddock
  • Publication number: 20150346378
    Abstract: Systems and methods for generating a multi-dimensional distribution function. First data and second data may be received in response to one or more radiofrequency pulses that are transmitted into a subterranean formation. The first data may include Carr-Purcell-Meiboom-Gill data, and the second data may include diffusion editing data with initial echo spacings longer than subsequent echo spacings. The second data may be inverted. A multi-dimensional distribution function may be determined using the inverted second data.
    Type: Application
    Filed: June 2, 2015
    Publication date: December 3, 2015
    Inventors: Ravinath Kausik Kadayam Viswanathan, Martin D. Hurlimann, Colm Ryan, Frank P. Shray, Yi-Qiao Song
  • Patent number: 9176081
    Abstract: Systems and methods for magic angle spinning nuclear magnetic resonance analysis of samples from unconventional reservoirs are described. Fast and inexpensive methods are described that can provide reliable information on TOC content, type, and maturity (via the relative abundances of different hydrocarbons, for example) without the need for more extensive sample preparation or destruction. If care is taken during sample recovery and storage, NMR can also yield an estimate of gas-in-place, including detailed typing (e.g. methane vs. ethane). The described MAS NMR analysis is used to determine various properties of unconventional reservoirs, including gas and oil shales, which are useful in evaluating their worth and producibility.
    Type: Grant
    Filed: April 29, 2011
    Date of Patent: November 3, 2015
    Assignee: Schlumberger Technology Corporation
    Inventors: Pabitra N. Sen, Gabriela Leu, Nicholas Drenzek, Thomas J. Neville, Yi-Qiao Song, Ravinath Kausik Kadayam Viswanathan
  • Publication number: 20150219782
    Abstract: Apparatus and methods for characterizing hydrocarbons in a subterranean formation including sending and measuring NMR signals; analyzing the signals to form a distribution; and estimating a property of a formation from the distribution, wherein the sending comprises pulse sequences configured for a formation pore size, and wherein the computing comprises porosity. Apparatus and methods for characterizing hydrocarbons in a subterranean formation including sending and measuring NMR signals; analyzing the signals to form a distribution; and estimating a property of a formation from the distribution, wherein the formation comprises a distribution of pore sizes of about 10 nm or more, and wherein the computing comprises natural gas composition.
    Type: Application
    Filed: August 9, 2012
    Publication date: August 6, 2015
    Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: Ravinath Kausik Kadayam Viswanathan, Chanh Cao Minh, Ridvan Akkurt, Baarinadh Vissapragada, Yi-Qiao Song, Lukasz Zielinski
  • Publication number: 20150212233
    Abstract: A computer-implemented method for reservoir volumetric estimation, a non-transitory computer-readable medium, and a computing system. The method may include running a molecular dynamics simulation of a fluid-rock model of a first reservoir system at a plurality of pressures. The fluid-rock model includes a fluid that is at least partially adsorbed in the first reservoir system at one or more pressures of the plurality of pressures. The method may also include calculating a plurality of isothermal density profiles of the fluid in the first reservoir system, in association with the plurality of pressures using a result of the molecular dynamics simulation. The method may further include determining a first gas accumulation of the fluid in the first reservoir system for the plurality of isothermal density profiles. The first gas accumulation is at least partially a function of a pore surface area of a sample of the first reservoir system.
    Type: Application
    Filed: July 10, 2014
    Publication date: July 30, 2015
    Inventors: Mery Diaz Campos, Ravinath Kausik Kadayam Viswanathan
  • Publication number: 20150094960
    Abstract: Techniques for calculating metrics for reservoir quality based on light oil and total organic carbon in tight oil reservoirs are described. The techniques include calculating quantities of light oil and total organic carbon from logging data and generating therefrom a continuous log for reservoir quality metric. Additionally new reservoir quality indices are presented that more accurately predict reservoir quality in tight oil plays.
    Type: Application
    Filed: October 2, 2014
    Publication date: April 2, 2015
    Inventors: Ravinath Kausik Kadayam Viswanathan, Andrew E. Pomerantz, Richard Lewis, Paul Ryan Craddock, Robert L. Kleinberg, Frank P. Shray, Stacy Lynn Reeder Blanco
  • Publication number: 20150022202
    Abstract: Methods for analyzing a formation samples using nuclear magnetic resonance (NMR) are described herein. One method includes performing an NMR measurement of the formation sample to obtain NMR data. The NMR measurement detects NMR signals with echo times of less than or equal to 100 microseconds. The NMR data is analyzed to determine a measure of organic hydrogen content of the formation sample, such as (i) total organic hydrogen content, (ii) kerogen content, (iii) bitumen content, and/or (iv) oil content.
    Type: Application
    Filed: July 17, 2014
    Publication date: January 22, 2015
    Inventors: Yi-Qiao Song, Albina Rishatovna Mutina, Ravinath Kausik Kadayam Viswanathan, Martin Hurlimann
  • Publication number: 20140232391
    Abstract: An NMR method and apparatus for analyzing a sample of interest applies a static magnetic field together with RF pulses of oscillating magnetic field across a sample volume that encompasses the sample of interest. The RF pulses are defined by a pulse sequence that includes a plurality of measurement segments configured to characterize a plurality of relaxation parameters related to relaxation of nuclear magnetization of the sample of interest. Signals induced by the RF pulses are detected in order to derive the relaxation parameters. The measurement segments of the pulse sequence include at least one first-type measurement segment configured to characterize relaxation of spin-lattice interaction between nuclei of the sample of interest in a rotating frame (T1?) at a predefined frequency. The T1? parameter can be measured in conjunction with the measurement of other relaxation and/or diffusion parameters as part of multidimensional NMR experiments.
    Type: Application
    Filed: February 15, 2013
    Publication date: August 21, 2014
    Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: RAVINATH KAUSIK KADAYAM VISWANATHAN, LUKASZ ZIELINSKI, MARTIN D. HÜRLIMANN
  • Publication number: 20120273193
    Abstract: Systems and methods for magic angle spinning nuclear magnetic resonance analysis of samples from unconventional reservoirs are described. Fast and inexpensive methods are described that can provide reliable information on TOC content, type, and maturity (via the relative abundances of different hydrocarbons, for example) without the need for more extensive sample preparation or destruction. If care is taken during sample recovery and storage, NMR can also yield an estimate of gas-in-place, including detailed typing (e.g. methane vs. ethane). The described MAS NMR analysis is used to determine various properties of unconventional reservoirs, including gas and oil shales, which are useful in evaluating their worth and producibility.
    Type: Application
    Filed: April 29, 2011
    Publication date: November 1, 2012
    Applicant: Schlumberger Technology Corporation
    Inventors: Pabitra N. Sen, Gabriela Leu, Nicholas Drenzek, Thomas J. Neville, Yi-Qiao Song, Ravinath Kausik Kadayam Viswanathan