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).
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Patent number: 12077709Abstract: Pumpable slurry compositions comprising at least one aluminosilicate additive and optional pozzolanic cement additives and methods for improving development of compressive strengths in the pumpable cement slurry compositions are disclosed herein. The methods utilize one or more pumpable cement slurry compositions comprising at least one cement component, water, at least one first aluminosilicate additive, at least one optional second aluminosilicate additive, and one or more optional pozzolanic additives, wherein the at least one first aluminosilicate additive has an amorphous phase of greater than about 50% and a weight ratio of silica oxide to aluminum oxide of about 1.0 to about 2.5, and the at least one optional second aluminosilicate additive has a weight ratio of silica oxide to aluminum oxide of about 1.7 to about 3.3.Type: GrantFiled: December 2, 2022Date of Patent: September 3, 2024Assignee: Schlumberger Technology CorporationInventors: Bernardo Engelke, Lynn Foster, Valerie Lafitte
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Publication number: 20240182774Abstract: Pumpable slurry compositions comprising at least one aluminosilicate additive and optional pozzolanic cement additives and methods for improving development of compressive strengths in the pumpable cement slurry compositions are disclosed herein. The methods utilize one or more pumpable cement slurry compositions comprising at least one cement component, water, at least one first aluminosilicate additive, at least one optional second aluminosilicate additive, and one or more optional pozzolanic additives, wherein the at least one first aluminosilicate additive has an amorphous phase of greater than about 50% and a weight ratio of silica oxide to aluminum oxide of about 1.0 to about 2.5, and the at least one optional second aluminosilicate additive has a weight ratio of silica oxide to aluminum oxide of about 1.7 to about 3.3.Type: ApplicationFiled: December 2, 2022Publication date: June 6, 2024Inventors: Bernardo Engelke, Lynn Foster, Valerie Lafitte
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Patent number: 10240083Abstract: 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: GrantFiled: May 10, 2013Date of Patent: March 26, 2019Assignee: SCHLUMBERGER TECHNOLOGY CORPORATIONInventors: Gary John Tustin, Valerie Lafitte, Bruno Drochon
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Patent number: 9804123Abstract: 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: GrantFiled: May 1, 2009Date of Patent: October 31, 2017Assignee: SCHLUMBERGER TECHNOLOGY CORPORATIONInventors: Valerie Lafitte, Nathan Lawrence
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Patent number: 9523667Abstract: 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: GrantFiled: August 13, 2012Date of Patent: December 20, 2016Assignee: SCHLUMBERGER TECHNOLOGY CORPORATIONInventors: Valerie Lafitte, Gary John Tustin
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Patent number: 9377434Abstract: 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: GrantFiled: October 14, 2010Date of Patent: June 28, 2016Assignee: SCHLUMBERGER TECHNOLOGY CORPORATIONInventors: Valerie Lafitte, Nathan S. Lawrence
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Patent number: 9290689Abstract: 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: GrantFiled: June 3, 2009Date of Patent: March 22, 2016Assignee: Schlumberger Technology CorporationInventors: Valerie Lafitte, Trevor Hughes, Slaheddine Kefi, Matthew Miller, Gary Tustin, Shiyi Wang
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Publication number: 20150129226Abstract: 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: ApplicationFiled: May 10, 2013Publication date: May 14, 2015Inventors: Gary John Tustin, Valerie Lafitte, Bruno Drochon
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Publication number: 20150072902Abstract: 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: ApplicationFiled: November 16, 2014Publication date: March 12, 2015Inventors: Valerie Lafitte, Jesse C. Lee, Simon Gareth James, Julia Fernandez Del Valle, Andrey Vladimirovich Yakovlev, Mohan K.R. Panga, Geza Horvath Szabo
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Patent number: 8758593Abstract: 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: GrantFiled: August 6, 2010Date of Patent: June 24, 2014Assignee: Schlumberger Technology CorporationInventors: Nathan Lawrence, Valerie Lafitte
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Patent number: 8695708Abstract: 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: GrantFiled: September 1, 2010Date of Patent: April 15, 2014Assignee: Schlumberger Technology CorporationInventors: Andrey Fedorov, Olesya Levanyuk, Tatiana Zolnikova, Vadim Khlestkin, Alexander Nadeev, Diankui Fu, Bruno Lecerf, Shiyi Wang, Gary John Tustin, Valerie Lafitte
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Publication number: 20130312970Abstract: 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: ApplicationFiled: November 22, 2011Publication date: November 28, 2013Applicant: SCHLUMBERGER TECHNOLOGY CORPORATIONInventors: Valerie Lafitte, Laetitia Corde, Laurent Pirolli, Gary John Tustin, Bruno Drochon
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Publication number: 20130274149Abstract: 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: ApplicationFiled: March 15, 2013Publication date: October 17, 2013Applicant: SCHLUMBERGER TECHNOLOGY CORPORATIONInventors: Valerie Lafitte, Jesse C. Lee, Syed A. Ali, Philip F. Sullivan
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Publication number: 20130062222Abstract: 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: ApplicationFiled: August 13, 2012Publication date: March 14, 2013Applicant: SCHLUMBERGER TECHNOLOGY CORPORATIONInventors: Valerie LAFITTE, Gary John TUSTIN
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Patent number: 8393395Abstract: 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: GrantFiled: June 3, 2009Date of Patent: March 12, 2013Assignee: Schlumberger Technology CorporationInventors: Thomas Cochet, Trevor Hughes, Slaheddine Kefi, Valerie Lafitte, Khooi Tan, Gary Tustin, Shiyi Wang
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Publication number: 20120268134Abstract: 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: ApplicationFiled: October 14, 2010Publication date: October 25, 2012Inventors: Valerie Lafitte, Nathan S. Lawrence
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Publication number: 20110162977Abstract: 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: ApplicationFiled: May 1, 2009Publication date: July 7, 2011Applicant: Schlumberger Technology CorporationInventors: Valerie Lafitte, Nathan Lawrence
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Publication number: 20110048969Abstract: 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: ApplicationFiled: August 6, 2010Publication date: March 3, 2011Inventors: Nathan Lawrence, Valerie Lafitte
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Publication number: 20100307745Abstract: 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: ApplicationFiled: June 3, 2009Publication date: December 9, 2010Applicant: Schlumberger Technology CorporationInventors: Valerie Lafitte, Trevor Hughes, Slaheddine Kefi, Mathew Miller, Gary Tustin, Shiyi Wang
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Publication number: 20100307744Abstract: 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: ApplicationFiled: June 3, 2009Publication date: December 9, 2010Applicant: Schlumberger Technology CorporationInventors: Thomas Cochet, Trevor Hughes, Slaheddine Kefi, Valerie Lafitte, Khooi Tan, Gary Tustin, Shiyi Wang