Patents by Inventor Christopher Sawdon

Christopher Sawdon 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: 6861394
    Abstract: A wellbore fluid including a peroxide degradable polymer and an encapsulated peroxide source. The peroxide degradable polymer may be a polysaccharide. The peroxide source may include an inorganic peroxide, including zinc and alkaline earth metal peroxides, such as magnesium peroxide. The encapsulating material may be a polymer, including enteric polymers. The release of peroxide, from peroxide sources generally, can be controlled by means of pH such that peroxide source can be activated, and peroxide released, by a change in pH. In a wellbore, this pH change can be effected by using produced fluids to lower the pH of a more basic wellbore fluid.
    Type: Grant
    Filed: December 19, 2001
    Date of Patent: March 1, 2005
    Assignee: M-I L.L.C.
    Inventors: David A. Ballard, Christopher A. Sawdon, Trevor G. Jappy
  • Publication number: 20040259739
    Abstract: The invention concerns modified hydrophobic polyelectrolytes by amide formation of a hydrophilic skeleton by n-alkylamines whereof the alkyl chain comprises 6 to 22 carbon atoms. Preferably, the amide formation is obtained by di-n-dodecylamine. The hydrophilic skeleton is preferably a sodium polyacrylate or polyacrylic acid corresponding to a statistical acrylate-AMPS copolymer. Said polymers can be used for stabilizing direct or invert emulsions likely to be destabilized or inverted by a modification in the degree of salinity of the aqueous phase or a pH modification. The invention is particularly useful for stabilizing oil drilling fluids or the like in particular drilling, fracturation, acidification or completion fluids.
    Type: Application
    Filed: July 16, 2004
    Publication date: December 23, 2004
    Inventors: Nathalie Monfreux-Gaillard, Patrick Perrin, Francoise LaFuma, Christopher Sawdon
  • Patent number: 6803347
    Abstract: A low molecular weight, high melting point, crystalline, oil soluble additive for use in wellbore fluids is provided that is preferably a ground crystalline material of melting point over 80° C., preferably over 100° C. which is readily soluble in produced hydrocarbons such as crude oil and lighter condensates, and which exhibits a molecular weight of less than 1000, and preferably less than 500, and more preferably less than 300. Its particle size can be adjusted to bridge efficiently across different pore size formations and control its solubility rate.
    Type: Grant
    Filed: March 23, 2000
    Date of Patent: October 12, 2004
    Assignee: Schlumberger Technology Corporation
    Inventors: Hemant K. J. Ladva, Christopher A. Sawdon, Paul R. Howard
  • Patent number: 6787505
    Abstract: A wellbore fluid having a non-aqueous continuous liquid phase that exhibits an electrical conductivity of not less than 10 &mgr;S m−1 at 1 kHz comprises a polar organic liquid (POL) which exhibits a dielectric constant of at least about 5.0 and a Hildebrand Solubility Parameter of at least about 17 (J cm−3)1/2. Oils or other organic liquids (OL) known to be suitable as the continuous liquid phase of wellbore fluids, may be used in admixture with POL component. Certain inorganic salts, organic bases, quaternary ammonium salts or hydroxides (the dissolved component, DC), display sufficient solubility (and current carrying abilities) in POL, OL or in mixtures of liquid (POL) and liquid (OL) to further improve the electrical conductivity of the mixture. The wellbore fluid can be used for providing enhanced information from electrical logging tools, measurement while drilling, logging while drilling, geosteering and the like.
    Type: Grant
    Filed: June 8, 2000
    Date of Patent: September 7, 2004
    Assignee: M-I LLC
    Inventors: Geoffrey Maitland, Christopher Sawdon, Mostafa Tehrani
  • Patent number: 6770603
    Abstract: A wellbore fluid having a non-aqueous continuous liquid phase that exhibits an electrical conductivity increased by a factor in order of 104 to 107 compared to conventional invert emulsion comprises from about 0.2% to about 10% by volume of carbon black particles and one or more emulsifying surfactant(s) selected from the class including nonionic emulsifiers of Hydrophilic-Lipophilic Balance (HLB) less than about 12, and anionic surfactants wherein the counter-ion (cation) is any of alkali metal, ammonium, or hydrogen ions. This wellbore fluid can be used for drilling or completing a well and can be used for providing enhanced information from electrical logging tools, measurement while drilling, logging while drilling, geosteering and the like.
    Type: Grant
    Filed: February 5, 2002
    Date of Patent: August 3, 2004
    Assignee: M-I L.L.C.
    Inventors: Christopher Sawdon, Mostafa Tehrani, Paul Craddock, Anthony Lawson
  • Publication number: 20040127366
    Abstract: A wellbore fluid having an oleaginous phase and an additive for increasing the density of the wellbore fluid. The additive comprises solid colloidal particles coated with a dispersant coated onto the colloidal particle during the comminution process of forming the particles. Exemplary starting materials for the colloidal particles include commonly known weighting agents including barite, calcium carbonate, dolomite, ilmenite, hematite or other iron ores, olivine, siderite, and strontium sulfate as well as mixture and combinations of these and other similar weighting materials. The dispersant in one illustrative embodiment, is selected from carboxylic acids of molecular weight of at least 150 Daltons.
    Type: Application
    Filed: June 30, 2003
    Publication date: July 1, 2004
    Applicant: M-I LLC
    Inventors: Andrew J. Bradbury, Jarrod Massam, Christopher A. Sawdon
  • Publication number: 20030203822
    Abstract: A method of controlling the pressure of a casing annulus in a subterranean well that includes injecting into the casing annulus a composition including a base fluid and a polymer coated colloidal solid material. The polymer coated colloidal solid material includes: a solid particle having an weight average particle diameter (d50) of less than two microns, and a polymeric dispersing agent coated onto the surface of the solid particle during the cominution (i.e. grinding) process utilized to make the colloidal particles. The polymeric dispersing agent may be a water soluble polymer having a molecular weight of at least 2000 Daltons. The solid particulate material may be selected from materials having of specific gravity of at least 2.
    Type: Application
    Filed: October 18, 2002
    Publication date: October 30, 2003
    Inventors: Andrew J. Bradbury, Christopher A. Sawdon, Sonny Clary, William M. Reid, Tom Heinz
  • Patent number: 6586372
    Abstract: An additive which increases the density of wellbore fluids used during the construction or repair of oil, gas, injection, water or geothermal wells comprises solid colloidal particles of weight average particle diameter (D50) of less than 2 microns, the particles being deflocculated by the action of a dispersant, preferably incorporated during the process of grinding or communication of the particles to the specified particle size. The additives may be used in any wellbore fluid such as drilling, cementing, completion, packing, work-over (repairing), stimulation, well killing and spacer fluids as well as in a dense media separating fluid or in a ship's ballast fluid.
    Type: Grant
    Filed: September 10, 1999
    Date of Patent: July 1, 2003
    Assignee: M-I LLC.
    Inventors: Andrew Bradbury, Christopher A. Sawdon
  • Publication number: 20030114314
    Abstract: A wellbore fluid including a peroxide degradable polymer and an encapsulated peroxide source. The peroxide degradable polymer may be a polysaccharide. The peroxide source may include an inorganic peroxide, including zinc and alkaline earth metal peroxides, such as magnesium peroxide. The encapsulating material may be a polymer, including enteric polymers. The release of peroxide, from peroxide sources generally, can be controlled by means of pH such that peroxide source can be activated, and peroxide released, by a change in pH. In a wellbore, this pH change can be effected by using produced fluids to lower the pH of a more basic wellbore fluid.
    Type: Application
    Filed: December 19, 2001
    Publication date: June 19, 2003
    Inventors: David A. Ballard, Christopher A. Sawdon, Trevor G. Jappy
  • Patent number: 5627143
    Abstract: There is disclosed a biodegradable wellbore fluid having a continuous oil phase comprising an n-alk-1-ene having from 12 to 20 carbon atoms or a linear polyunsaturated olefin having one of the double bonds in the 1-position and having from 12 to 22 carbon atoms, or a mixture thereof.
    Type: Grant
    Filed: January 31, 1995
    Date of Patent: May 6, 1997
    Assignee: Dowell Schlumberger Incorporated
    Inventor: Christopher A. Sawdon