Patents by Inventor Sumitra Subrahmanyan

Sumitra Subrahmanyan 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: 20240067865
    Abstract: Embodiments of treating fluid comprising hydrocarbons, water, and polymer being produced from a hydrocarbon-bearing formation are provided. One embodiment comprises adding a concentration of a viscosity reducer to the fluid to degrade the polymer present in the fluid and adding a concentration of a neutralizer to the fluid to neutralize the viscosity reducer in the fluid. The addition of the concentration of the viscosity reducer is in a sufficient quantity to allow for complete chemical degradation of the polymer prior to the addition of the concentration of the neutralizer in the fluid such that excess viscosity reducer is present in the fluid. The addition of the concentration of the neutralizer is sufficiently upstream of any surface fluid processing equipment to allow for complete neutralization of the excess viscosity reducer such that excess neutralizer is present in the fluid prior to the fluid reaching any of the surface fluid processing equipment.
    Type: Application
    Filed: October 27, 2023
    Publication date: February 29, 2024
    Inventors: Sumitra SUBRAHMANYAN, Gayani W. PINNAWALA, Sophany THACH, Gregory A. WINSLOW, Dennis A. ALEXIS, Harold C. LINNEMEYER, Timothy P. THERIOT, Les Leszek JACKOWSKI, Francesca CIBOTTI
  • Patent number: 11834606
    Abstract: Embodiments of treating fluid comprising hydrocarbons, water, and polymer being produced from a hydrocarbon-bearing formation are provided. One embodiment comprises adding a concentration of a viscosity reducer to the fluid to degrade the polymer present in the fluid and adding a concentration of a neutralizer to the fluid to neutralize the viscosity reducer in the fluid. The addition of the concentration of the viscosity reducer is in a sufficient quantity to allow for complete chemical degradation of the polymer prior to the addition of the concentration of the neutralizer in the fluid such that excess viscosity reducer is present in the fluid. The addition of the concentration of the neutralizer is sufficiently upstream of any surface fluid processing equipment to allow for complete neutralization of the excess viscosity reducer such that excess neutralizer is present in the fluid prior to the fluid reaching any of the surface fluid processing equipment.
    Type: Grant
    Filed: January 21, 2022
    Date of Patent: December 5, 2023
    Assignee: CHEVRON U.S.A. INC.
    Inventors: Sumitra Subrahmanyan, Gayani W. Pinnawala, Sophany Thach, Gregory A. Winslow, Dennis A. Alexis, Harold C. Linnemeyer, Timothy P. Theriot, Les Leszek Jackowski, Francesca Cibotti
  • Publication number: 20230323193
    Abstract: Embodiments of treating fluid comprising hydrocarbons, water, and polymer being produced from a hydrocarbon-bearing formation are provided. One embodiment comprises adding a concentration of a viscosity reducer to the fluid to degrade the polymer present in the fluid and adding a concentration of a neutralizer to the fluid to neutralize the viscosity reducer in the fluid. The viscosity reducer is buffered at a pH of 7 or less (e.g., at a pH of from 2 to 7, such as at a pH of from 3.5 to 7, or at a pH of from 5 to 7). The addition of the concentration of the viscosity reducer is in a sufficient quantity to allow for complete chemical degradation of the polymer prior to the addition of the concentration of the neutralizer in the fluid such that excess viscosity reducer is present in the fluid.
    Type: Application
    Filed: January 27, 2023
    Publication date: October 12, 2023
    Inventors: Sujeewa S. PALAYANGODA, Kerry Kennedy SPILKER, Sumitra SUBRAHMANYAN, Gayani W. PINNAWALA, Sophany THACH, Gregory A. WINSLOW, Dennis Arun ALEXIS, Harold Charles LINNEMEYER, Timothy P. THERIOT, Les Leszek JACKOWSKI, Francesca CIBOTTI
  • Patent number: 11591893
    Abstract: Described herein are methods of treating fluid comprising hydrocarbons, water, and polymer being produced from a hydrocarbon-bearing formation are provided. The method can include adding a concentration of a viscosity reducer to the fluid to degrade the polymer present in the fluid and adding a concentration of a neutralizer to the fluid to neutralize the viscosity reducer in the fluid. The viscosity reducer is buffered at a pH of 7 or less (e.g., at a pH of from 2 to 7, such as at a pH of from 3.5 to 7, or at a pH of from 5 to 7). The addition of the concentration of the viscosity reducer is in a sufficient quantity to allow for complete chemical degradation of the polymer prior to the addition of the concentration of the neutralizer in the fluid such that excess viscosity reducer is present in the fluid.
    Type: Grant
    Filed: October 22, 2019
    Date of Patent: February 28, 2023
    Assignee: CHEVRON U.S.A. INC.
    Inventors: Sujeewa S. Palayangoda, Kerry Kennedy Spilker, Sumitra Subrahmanyan, Gayani W. Pinnawala, Sophany Thach, Gregory A. Winslow, Dennis Arun Alexis, Harold Charles Linnemeyer, Timothy P. Theriot, Les Leszek Jackowski, Francesca Cibotti
  • Publication number: 20220145157
    Abstract: Embodiments of treating fluid comprising hydrocarbons, water, and polymer being produced from a hydrocarbon-bearing formation are provided. One embodiment comprises adding a concentration of a viscosity reducer to the fluid to degrade the polymer present in the fluid and adding a concentration of a neutralizer to the fluid to neutralize the viscosity reducer in the fluid. The addition of the concentration of the viscosity reducer is in a sufficient quantity to allow for complete chemical degradation of the polymer prior to the addition of the concentration of the neutralizer in the fluid such that excess viscosity reducer is present in the fluid. The addition of the concentration of the neutralizer is sufficiently upstream of any surface fluid processing equipment to allow for complete neutralization of the excess viscosity reducer such that excess neutralizer is present in the fluid prior to the fluid reaching any of the surface fluid processing equipment.
    Type: Application
    Filed: January 21, 2022
    Publication date: May 12, 2022
    Inventors: Sumitra Subrahmanyan, Gayani W. Pinnawala, Sophany Thach, Gregory A. Winslow, Dennis A. Alexis, Harold C. Linnemeyer, Timothy P. Theriot, Les Leszek Jackowski, Francesca Cibotti
  • Patent number: 11242739
    Abstract: Embodiments of treating fluid comprising hydrocarbons, water, and polymer being produced from a hydrocarbon-bearing formation are provided. One embodiment comprises adding a concentration of a viscosity reducer to the fluid to degrade the polymer present in the fluid and adding a concentration of a neutralizer to the fluid to neutralize the viscosity reducer in the fluid. The addition of the concentration of the viscosity reducer is in a sufficient quantity to allow for complete chemical degradation of the polymer prior to the addition of the concentration of the neutralizer in the fluid such that excess viscosity reducer is present in the fluid. The addition of the concentration of the neutralizer is sufficiently upstream of any surface fluid processing equipment to allow for complete neutralization of the excess viscosity reducer such that excess neutralizer is present in the fluid prior to the fluid reaching any of the surface fluid processing equipment.
    Type: Grant
    Filed: October 22, 2019
    Date of Patent: February 8, 2022
    Assignee: Chevron U.S.A. Inc.
    Inventors: Sumitra Subrahmanyan, Gayani W. Pinnawala, Sophany Thach, Gregory A. Winslow, Dennis Arun Alexis, Harold Charles Linnemeyer, Timothy Peter Theriot, Les Leszek Jackowski, Francesca Cibotti
  • Publication number: 20210395602
    Abstract: Embodiments of treating fluid comprising hydrocarbons, water, and polymer being produced from a hydrocarbon-bearing formation are provided. One embodiment comprises adding a concentration of a viscosity reducer to the fluid to degrade the polymer present in the fluid and adding a concentration of a neutralizer to the fluid to neutralize the viscosity reducer in the fluid. The viscosity reducer is buffered at a pH of 7 or less (e.g., at a pH of from 2 to 7, such as at a pH of from 3.5 to 7, or at a pH of from 5 to 7). The addition of the concentration of the viscosity reducer is in a sufficient quantity to allow for complete chemical degradation of the polymer prior to the addition of the concentration of the neutralizer in the fluid such that excess viscosity reducer is present in the fluid.
    Type: Application
    Filed: October 22, 2019
    Publication date: December 23, 2021
    Inventors: Sujeewa S. PALAYANGODA, Kerry Kennedy SPILKER, Sumitra SUBRAHMANYAN, Gayani W. PINNAWALA, Sophany THACH, Gregory A. WINSLOW, Dennis Arun ALEXIS, Harold Charles LINNEMEYER, Timothy P. THERIOT, Les Leszek JACKOWSKI, Francesca CIBOTTI
  • Publication number: 20200123889
    Abstract: Embodiments of treating fluid comprising hydrocarbons, water, and polymer being produced from a hydrocarbon-bearing formation are provided. One embodiment comprises adding a concentration of a viscosity reducer to the fluid to degrade the polymer present in the fluid and adding a concentration of a neutralizer to the fluid to neutralize the viscosity reducer in the fluid. The addition of the concentration of the viscosity reducer is in a sufficient quantity to allow for complete chemical degradation of the polymer prior to the addition of the concentration of the neutralizer in the fluid such that excess viscosity reducer is present in the fluid. The addition of the concentration of the neutralizer is sufficiently upstream of any surface fluid processing equipment to allow for complete neutralization of the excess viscosity reducer such that excess neutralizer is present in the fluid prior to the fluid reaching any of the surface fluid processing equipment.
    Type: Application
    Filed: October 22, 2019
    Publication date: April 23, 2020
    Inventors: Sumitra Subrahmanyan, Gayani W. Pinnawala, Sophany Thach, Gregory A. Winslow, Dennis Arun Alexis, Harold Charles Linnemeyer, Timothy Peter Theriot, Les Leszek Jackowski, Francesca Cibotti
  • Patent number: 9909053
    Abstract: Embodiments of a polymer composition are disclosed for use in enhancing the production of oil from a formation. In one embodiment, the composition includes a powder polymer having an average molecular weight of 0.5 to 30 Million Daltons suspended in a water soluble solvent having an HLB of greater than or equal to 8 and selected from the group of surfactants, glycol ethers, alcohols, co-solvents, and mixtures thereof, at a weight ratio of powder polymer to water soluble solvent ranging from 20:80 to 80:20. The polymer composition is substantially anhydrous. The polymer composition is hydrated in an aqueous fluid for an injection solution in less than or equal to 4 hours containing a polymer concentration ranging from 100 ppm to 50,000 ppm and having a filter ratio of less than or equal to 1.5 at 15 psi using a 1.2 ?m filter.
    Type: Grant
    Filed: October 29, 2015
    Date of Patent: March 6, 2018
    Assignee: CHEVRON U.S.A. INC.
    Inventors: Varadarajan Dwarakanath, Robert M. Dean, Do Hoon Kim, Dennis Arun Alexis, Sophany Thach, Taimur Malik, Anette Poulsen, Sumitra Subrahmanyan
  • Patent number: 9902894
    Abstract: A method for making a polymer suspension for use in enhancing the production of oil from a formation is disclosed. In one embodiment, the method comprises mixing a powder polymer having an average molecular weight of 0.5 to 30 Million Daltons into a water soluble solvent having an HLB of greater than or equal to 8 for less than or equal to 24 hours. The water soluble solvent is selected from a group, at a weight ratio from 20:80 to 80:20. The polymer suspension is stable, pumpable, and substantially anhydrous; and it is hydrated for an injection solution in less than or equal to 4 hours, containing a polymer concentration ranging from 100 ppm to 50,000 ppm and having a filter ratio of less than or equal to 1.5 at 15 psi using a 1.2 ?m filter, by mixing a sufficient amount of the polymer suspension in an aqueous fluid.
    Type: Grant
    Filed: October 29, 2015
    Date of Patent: February 27, 2018
    Assignee: CHEVRON U.S.A. INC.
    Inventors: Varadarajan Dwarakanath, Robert M. Dean, Do Hoon Kim, Dennis Arun Alexis, Sophany Thach, Taimur Malik, Anette Poulsen, Sumitra Subrahmanyan
  • Patent number: 9902895
    Abstract: An injection solution for injecting into a subterranean reservoir to enhance production and recovery of oil from the reservoir is disclosed. In one embodiment, the injection solution is prepared by mixing a sufficient amount of a pumpable, stable and substantially anhydrous polymer suspension in an aqueous fluid for the polymer to be hydrated in less than or equal to 4 hours, resulting in the injection solution containing a polymer concentration ranging from 100 ppm to 50,000 ppm. The injection solution has a filter ratio of less than or equal to 1.5 at 15 psi using a 1.2 ?m filter. The polymer suspension comprises a powder polymer having an average molecular weight of 0.5 to 30 Million Daltons suspended in a water soluble solvent having an HLB of greater than or equal to 8 and selected from a group, at a weight ratio from 20:80 to 80:20.
    Type: Grant
    Filed: October 29, 2015
    Date of Patent: February 27, 2018
    Assignee: CHEVRON U.S.A. INC.
    Inventors: Varadarajan Dwarakanath, Robert M. Dean, Do Hoon Kim, Dennis Arun Alexis, Sophany Thach, Taimur Malik, Anette Poulsen, Sumitra Subrahmanyan
  • Patent number: 9896617
    Abstract: A method of enhancing oil recovery in a subterranean reservoir is disclosed. In one embodiment, the method comprises providing a wellbore and a polymer suspension. The polymer suspension comprises a powder polymer having an average molecular weight of 0.5 to 30 Million Daltons suspended in a water soluble solvent having an HLB of greater than or equal to 8 and selected from a group, at a weight ratio of 20:80 to 80:20. The method comprises providing an aqueous fluid, mixing a sufficient amount of the polymer suspension in the aqueous fluid for the polymer to be hydrated resulting an injection solution in less than or equal to 4 hours, and injecting the injection solution into the wellbore. The injection solution contains a polymer concentration ranging from 100 ppm to 50,000 ppm and has a filter ratio of less than 1.5 at 15 psi using a 1.2 ?m filter.
    Type: Grant
    Filed: October 29, 2015
    Date of Patent: February 20, 2018
    Assignee: CHEVRON U.S.A. INC.
    Inventors: Varadarajan Dwarakanath, Robert M. Dean, Do Hoon Kim, Dennis Arun Alexis, Sophany Thach, Taimur Malik, Anette Poulsen, Sumitra Subrahmanyan
  • Patent number: 9630349
    Abstract: Improved solventless processing technology for additive blends containing a polymer carrier, including those which have high level of additives, is described. High concentrations of low-melting, sticky additives lead to phase separation and extrusion instability, such that pellets cannot be formed from such additive blends by traditional extrusion process. These blends include those with a high level of active additives that have been described in the literature as Type A Superblends. Here a polymer typically acts as the carrier of the additives. The new and improved technology involves the solid state compaction processing, using a tubular die, of such impossible-to-pelletize additive blends of the Type A composition to produce commercially useful pelletized additive blends.
    Type: Grant
    Filed: August 26, 2014
    Date of Patent: April 25, 2017
    Assignee: Ingenia Polymers, Inc.
    Inventors: Ananda M. Chatterjee, Sumitra Subrahmanyan
  • Publication number: 20160122624
    Abstract: An injection solution for injecting into a subterranean reservoir to enhance production and recovery of oil from the reservoir is disclosed. In one embodiment, the injection solution is prepared by mixing a sufficient amount of a pumpable, stable and substantially anhydrous polymer suspension in an aqueous fluid for the polymer to be hydrated in less than or equal to 4 hours, resulting in the injection solution containing a polymer concentration ranging from 100 ppm to 50,000 ppm. The injection solution has a filter ratio of less than or equal to 1.5 at 15 psi using a 1.2 ?m filter. The polymer suspension comprises a powder polymer having an average molecular weight of 0.5 to 30 Million Daltons suspended in a water soluble solvent having an HLB of greater than or equal to 8 and selected from a group, at a weight ratio from 20:80 to 80:20.
    Type: Application
    Filed: October 29, 2015
    Publication date: May 5, 2016
    Inventors: Varadarajan Dwarakanath, Robert M. Dean, Do Hoon Kim, Dennis Arun Alexis, Sophany Thach, Taimur Malik, Anette Poulsen, Sumitra Subrahmanyan
  • Publication number: 20150376033
    Abstract: Produced water from a crude oil or natural gas production process is purified using a membrane purification system for petroleum production, agricultural, commercial and domestic uses. The produced water is pretreated to remove, at least, particulates and oil from the produced water. The minimally pretreated water is then purified in a membrane purification system that is operated at conditions such that membrane scaling is reduced or prevented. In particular, the membrane purification system is operated to maintain the turbidity of clarified water feed to the system or intermediate aqueous streams that are cascading through the membrane purification system. Ensuring that the turbidity of the reject streams generated in the membrane system are useful in achieving long membrane operating life.
    Type: Application
    Filed: August 28, 2015
    Publication date: December 31, 2015
    Inventors: Fan-Sheng Teddy Tao, Ronald David Hobbs, Cheng Chen, Sumitra Subrahmanyan
  • Publication number: 20150122151
    Abstract: A melt extrusion process for producing pelletized 100% additive blends using additives with lower Hausner ratio and larger particle size with granular form, compared to powder form of additives; also additive blends produced by such process. Extrusion throughput rate is increased using granular additive particle form with lower Hausner ratio than that of powder form. The productivity and efficiency of the process is enhanced by using a larger particle size of additives. Additive blends and polymer stabilization agent blends can be added in post-polymerization processes in resin manufacturing plants to enhance the processing and performance properties of polymers.
    Type: Application
    Filed: November 4, 2014
    Publication date: May 7, 2015
    Inventors: Ananda M. Chatterjee, Sumitra Subrahmanyan
  • Publication number: 20150057398
    Abstract: Improved solventless processing technology for additive blends containing a polymer carrier, including those which have high level of additives, is described. High concentrations of low-melting, sticky additives lead to phase separation and extrusion instability, such that pellets cannot be formed from such additive blends by traditional extrusion process. These blends include those with a high level of active additives that have been described in the literature as Type A Superblends. Here a polymer typically acts as the carrier of the additives. The new and improved technology involves the solid state compaction processing, using a tubular die, of such impossible-to-pelletize additive blends of the Type A composition to produce commercially useful pelletized additive blends.
    Type: Application
    Filed: August 26, 2014
    Publication date: February 26, 2015
    Inventors: Ananda M. Chatterjee, Sumitra Subrahmanyan