Patents by Inventor Valerie Lafitte

Valerie Lafitte 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: 10240083
    Abstract: An aqueous fluid, possibly a wellbore fracturing fluid, comprises an aqueous solution or dispersion of a first polymer, which may be polysaccharide, as a thickener and a cross linking agent to enhance the viscosity of the fluid by crosslinking the first polymer, wherein the crosslinking agent is a second polymer comprising at least one polymer chain with phenyl boronate groups distributed along the polymer chain and the phenyl boronic acid groups have nitrogen attached to the phenyl group at a position which is meta relative to the boronate group.
    Type: Grant
    Filed: May 10, 2013
    Date of Patent: March 26, 2019
    Assignee: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: Gary John Tustin, Valerie Lafitte, Bruno Drochon
  • Patent number: 9804123
    Abstract: An electrochemical sensor utilizes a chemical compound which is not a macromolecule but rather is a single chemical compound of determinate structure, incorporating two redox systems which differ in their response to a species to be detected. In one form, one redox system displays a voltammetric wave which is pH dependent while another displays a voltammetric wave which is pH independent and acts as an internal reference. The sensor comprises a solid substrate, which may be carbonaceous, on which the compound is immobilized. The sensor may be incorporated into a tool to be suspended in a wellbore.
    Type: Grant
    Filed: May 1, 2009
    Date of Patent: October 31, 2017
    Assignee: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: Valerie Lafitte, Nathan Lawrence
  • Patent number: 9523667
    Abstract: An electrochemical sensor measuring concentration of an analyte in a test fluid at 50° C. or above by voltammetry uses electrodes in contact with an electrolyte containing the analyte and a redox-active species electrochemically convertible between reduced and oxidised forms. At least one form of the redox active species is present within surfactant micelles. The surfactant micelles enhance thermal stability of the redox active species and may also solubilise a species with poor water solubility, such as t-butylferrocene. A downhole tool incorporating such a sensor comprises a barrier, permeable to the analyte, to separate the electrolyte from subterranean reservoir fluid, so that the sensor directly measures analyte which has passed through the barrier and thereby indirectly measures analyte in the test fluid.
    Type: Grant
    Filed: August 13, 2012
    Date of Patent: December 20, 2016
    Assignee: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: Valerie Lafitte, Gary John Tustin
  • Patent number: 9377434
    Abstract: An electrochemical sensor for the presence or concentration of an analyte has at least one electrode and at least one electrochemically active species able to undergo electrochemical reaction in response to electrical potential applied to the electrode, where the said reaction is modified by the presence of the analyte. This sensor has the novel characteristic that at least one said electrochemically active species is encapsulated within polymer particles. These particles are preferably formed from an amorphous polymer with a glass transition temperature above the temperature of the fluid to which the sensor is exposed. The encapsulating polymer protects the analyte species from degradation, but a small analyte such as a hydrogen or bisulfide ion can pass through the polymer and undergo reaction at the active species.
    Type: Grant
    Filed: October 14, 2010
    Date of Patent: June 28, 2016
    Assignee: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: Valerie Lafitte, Nathan S. Lawrence
  • Patent number: 9290689
    Abstract: A process of making observations of a subterranean reservoir penetrated by a wellbore uses distinguishable sets of tracer particles and comprises steps of: (i) delivering a plurality of sets of tracer particles to respective subterranean locations via the wellbore, the particles in each set comprising a tracer substance which distinguishes that set form the other sets; (ii) causing or allowing the tracer substances to flow out from the tracer particles whilst the particles are at the respective subterranean locations; (iii) causing or allowing production of fluid out of said reservoir via the wellbore; and (iv) detecting the presence or absence of the tracer substances in the produced fluid. The tracer substances are sufficiently distinguishable from each other to enable a tracer substance detected in the produced fluid to identify the set of tracer particles from which it has come and hence identify the location from which it has come.
    Type: Grant
    Filed: June 3, 2009
    Date of Patent: March 22, 2016
    Assignee: Schlumberger Technology Corporation
    Inventors: Valerie Lafitte, Trevor Hughes, Slaheddine Kefi, Matthew Miller, Gary Tustin, Shiyi Wang
  • Publication number: 20150129226
    Abstract: An aqueous fluid, possibly a wellbore fracturing fluid, comprises an aqueous solution or dispersion of a first polymer, which may be polysaccharide, as a thickener and a cross linking agent to enhance the viscosity of the fluid by crosslinking the first polymer, wherein the crosslinking agent is a second polymer comprising at least one polymer chain with phenyl boronate groups distributed along the polymer chain and the phenyl boronic acid groups have nitrogen attached to the phenyl group at a position which is meta relative to the boronate group.
    Type: Application
    Filed: May 10, 2013
    Publication date: May 14, 2015
    Inventors: Gary John Tustin, Valerie Lafitte, Bruno Drochon
  • Publication number: 20150072902
    Abstract: Treatment fluids and methods for treating a subterranean formation include introducing a treatment fluid into a subterranean formation, the treatment fluid containing a nanocrystalline cellulose. The treatment fluid may be a fracturing fluid, well control fluid, well kill fluid, well cementing fluid, acid fracturing fluid, acid diverting fluid, a stimulation fluid, a sand control fluid, a completion fluid, a wellbore consolidation fluid, a remediation treatment fluid, a spacer fluid, a drilling fluid, a frac-packing fluid, water conformance fluid or a gravel packing fluid.
    Type: Application
    Filed: November 16, 2014
    Publication date: March 12, 2015
    Inventors: Valerie Lafitte, Jesse C. Lee, Simon Gareth James, Julia Fernandez Del Valle, Andrey Vladimirovich Yakovlev, Mohan K.R. Panga, Geza Horvath Szabo
  • Patent number: 8758593
    Abstract: An electrochemical sensor and a method for using an electrochemical sensor are described where the electrochemical sensor comprises a working electrode having thereon one or more redox species that are sensitive to an analyte to be measured and a polymer coating that provides for interaction between the redox species and the analyte.
    Type: Grant
    Filed: August 6, 2010
    Date of Patent: June 24, 2014
    Assignee: Schlumberger Technology Corporation
    Inventors: Nathan Lawrence, Valerie Lafitte
  • Patent number: 8695708
    Abstract: A method for treating a subterranean formation penetrated by a wellbore is provided. The method includes providing a treatment fluid containing a viscoelastic surfactant having at least one degradable linkage, a hydrolysable material, and a pH control material, and injecting the treatment fluid into a subterranean formation. The pH control material may have a pH equal or greater than about 9 and may include a strongly alkaline material and an oxidizing agent.
    Type: Grant
    Filed: September 1, 2010
    Date of Patent: April 15, 2014
    Assignee: Schlumberger Technology Corporation
    Inventors: Andrey Fedorov, Olesya Levanyuk, Tatiana Zolnikova, Vadim Khlestkin, Alexander Nadeev, Diankui Fu, Bruno Lecerf, Shiyi Wang, Gary John Tustin, Valerie Lafitte
  • Publication number: 20130312970
    Abstract: An aqueous fluid contains an aqueous solution or dispersion of a polymer to thicken the fluid together with a cross linking agent to enhance the viscosity of the fluid by crosslinking the polymer, wherein the crosslinking agent comprises supporting structures bearing functional groups to react with the polymer molecules and has a mean particle size of 2 nanometer or more. The supporting structures may be nanoparticles and the functional groups may be boronic acid groups. The concentration of boron in a thickened fluid may be low and in some instances there is resistance to applied pressure. The fluid may be a hydraulic fracturing fluid.
    Type: Application
    Filed: November 22, 2011
    Publication date: November 28, 2013
    Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: Valerie Lafitte, Laetitia Corde, Laurent Pirolli, Gary John Tustin, Bruno Drochon
  • Publication number: 20130274149
    Abstract: Treatment fluids and methods for treating a subterranean formation are disclosed that include introducing a treatment fluid into a subterranean formation, the treatment fluid containing a nanocrystalline cellulose.
    Type: Application
    Filed: March 15, 2013
    Publication date: October 17, 2013
    Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: Valerie Lafitte, Jesse C. Lee, Syed A. Ali, Philip F. Sullivan
  • Publication number: 20130062222
    Abstract: An electrochemical sensor measuring concentration of an analyte in a test fluid at 50° C. or above by voltammetry uses electrodes in contact with an electrolyte containing the analyte and a redox-active species electrochemically convertible between reduced and oxidised forms. At least one form of the redox active species is present within surfactant micelles. The surfactant micelles enhance thermal stability of the redox active species and may also solubilise a species with poor water solubility, such as t-butylferrocene. A downhole tool incorporating such a sensor comprises a barrier, permeable to the analyte, to separate the electrolyte from subterranean reservoir fluid, so that the sensor directly measures analyte which has passed through the barrier and thereby indirectly measures analyte in the test fluid.
    Type: Application
    Filed: August 13, 2012
    Publication date: March 14, 2013
    Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: Valerie LAFITTE, Gary John TUSTIN
  • Patent number: 8393395
    Abstract: A process for hydraulic fracturing of a subterranean reservoir formation penetrated by a wellbore includes pumping a fracturing fluid or other aqueous fluid from the surface via the wellbore and into the reservoir. This fluid is an aqueous suspension of particles which each comprise an oilfield chemical distributed within an encapsulating matrix of water-insoluble carrier material. The encapsulating matrix is chosen so as to provide a delayed release of the oilfield chemical from the particles into surrounding fluid, such that oilfield chemical is liberated from the particles after they have entered the fracture. The encapsulating matrix may be a polymer which is at least partially amorphous, with a glass transition temperature below the reservoir temperature.
    Type: Grant
    Filed: June 3, 2009
    Date of Patent: March 12, 2013
    Assignee: Schlumberger Technology Corporation
    Inventors: Thomas Cochet, Trevor Hughes, Slaheddine Kefi, Valerie Lafitte, Khooi Tan, Gary Tustin, Shiyi Wang
  • Publication number: 20120268134
    Abstract: An electrochemical sensor for the presence or concentration of an analyte has at least one electrode and at least one electrochemically active species able to undergo electrochemical reaction in response to electrical potential applied to the electrode, where the said reaction is modified by the presence of the analyte. This sensor has the novel characteristic that at least one said electrochemically active species is encapsulated within polymer particles. These particles are preferably formed from an amorphous polymer with a glass transition temperature above the temperature of the fluid to which the sensor is exposed. The encapsulating polymer protects the analyte species from degradation, but a small analyte such as a hydrogen or bisulfide ion can pass through the polymer and undergo reaction at the active species.
    Type: Application
    Filed: October 14, 2010
    Publication date: October 25, 2012
    Inventors: Valerie Lafitte, Nathan S. Lawrence
  • Publication number: 20110162977
    Abstract: An electrochemical sensor utilises a chemical compound which is not a macromolecule but rather is a single chemical compound of determinate structure, incorporating two redox systems which differ in their response to a species to be detected. In one form, one redox system displays a voltammetric wave which is pH dependent while another displays a voltammetric wave which is pH independent and acts as an internal reference. The sensor comprises a solid substrate, which may be carbonaceous, on which the compound is immobilized. The sensor may be incorporated into a tool to be suspended in a wellbore.
    Type: Application
    Filed: May 1, 2009
    Publication date: July 7, 2011
    Applicant: Schlumberger Technology Corporation
    Inventors: Valerie Lafitte, Nathan Lawrence
  • Publication number: 20110048969
    Abstract: An electrochemical sensor and a method for using an electrochemical sensor are described where the electrochemical sensor comprises a working electrode having thereon one or more redox species that are sensitive to an analyte to be measured and a polymer coating that provides for interaction between the redox species and the analyte.
    Type: Application
    Filed: August 6, 2010
    Publication date: March 3, 2011
    Inventors: Nathan Lawrence, Valerie Lafitte
  • Publication number: 20100307745
    Abstract: A process of making observations of a subterranean reservoir penetrated by a wellbore uses distinguishable sets of tracer particles and comprises steps of: (i) delivering a plurality of sets of tracer particles to respective subterranean locations via the wellbore, the particles in each set comprising a tracer substance which distinguishes that set form the other sets; (ii) causing or allowing the tracer substances to flow out from the tracer particles whilst the particles are at the respective subterranean locations; (iii) causing or allowing production of fluid out of said reservoir via the wellbore; and (iv) detecting the presence or absence of the tracer substances in the produced fluid. The tracer substances are sufficiently distinguishable from each other to enable a tracer substance detected in the produced fluid to identify the set of tracer particles from which it has come and hence identify the location from which it has come.
    Type: Application
    Filed: June 3, 2009
    Publication date: December 9, 2010
    Applicant: Schlumberger Technology Corporation
    Inventors: Valerie Lafitte, Trevor Hughes, Slaheddine Kefi, Mathew Miller, Gary Tustin, Shiyi Wang
  • Publication number: 20100307744
    Abstract: A process for hydraulic fracturing of a subterranean reservoir formation penetrated by a wellbore includes pumping a fracturing fluid or other aqueous fluid which is an aqueous suspension of particles which each comprise an oilfield chemical distributed within an encapsulating matrix of water-insoluble carrier_material from the surface via the wellbore and into the reservoir. The encapsulating matrix is chosen so as to provide a delayed release of the oilfield chemical from the particles into surrounding fluid, such that oilfield chemical is liberated from the particles after they have entered the fracture. The encapsulating matrix may be a polymer which is at least partially amorphous, with a glass transition temperature below the reservoir temperature.
    Type: Application
    Filed: June 3, 2009
    Publication date: December 9, 2010
    Applicant: Schlumberger Technology Corporation
    Inventors: Thomas Cochet, Trevor Hughes, Slaheddine Kefi, Valerie Lafitte, Khooi Tan, Gary Tustin, Shiyi Wang