Patents by Inventor David C. Berkshire

David C. Berkshire 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).

  • Treating wells with self-precipitating scale inhibitor
    Patent number: 4357248
    Abstract: The scaling of a producing well is inhibited by injecting a self-reacting alkaline aqueous solution of a pH-lowering reactant, a compound containing scale-inhibiting anions and a compound containing multivalent cations, which solution subsequently precipitates a slightly soluble scale inhibitor within the reservoir.
    Type: Grant
    Filed: April 21, 1981
    Date of Patent: November 2, 1982
    Assignee: Shell Oil Company
    Inventors: David C. Berkshire, Jimmie B. Lawson, Edwin A. Richardson
  • Chemical process for backsurging fluid through well casing perforations
    Patent number: 4289633
    Abstract: A backsurge of fluid through perforations in a well casing is chemically induced by injecting into the surrounding reservoir a solution which contains (a) nitrogen gas-generating reactants, (b) a reaction-retarding alkaline buffer, and (c) a pH-reducing reactant that is capable of subsequently overriding the buffer, so that a rapid production of gas and heat causes a backsurging of fluid into the wellbore.
    Type: Grant
    Filed: December 20, 1979
    Date of Patent: September 15, 1981
    Assignee: Shell Oil Company
    Inventors: Edwin A. Richardson, Ronald F. Scheuerman, David C. Berkshire
  • Temporarily plugging a subterranean reservoir with a self-foaming aqueous solution
    Patent number: 4232741
    Abstract: Portions of a subterranean reservoir are temporarily plugged by injecting an aqueous liquid solution which contains nitrogen gas-generating reactants, a foaming surfactant and a pH controlling system arranged so that the solution remains relatively unreactive within the well but forms a relatively immobile foam within the pores or other openings within the reservoir formation.
    Type: Grant
    Filed: July 30, 1979
    Date of Patent: November 11, 1980
    Assignee: Shell Oil Company
    Inventors: Edwin A. Richardson, Ronald F. Scheuerman, David C. Berkshire, Joseph Reisberg, James H. Lybarger
  • Chemical process for backsurging fluid through well casing perforations
    Patent number: 4219083
    Abstract: A backsurge of fluid through perforations in a well casing is chemically induced by injecting into the surrounding reservoir a solution which contains (a) nitrogen gas-generating reactants, (b) a reaction-retarding alkaline buffer, and (c) a pH-reducing reactant that is capable of subsequently overriding the buffer, so that a rapid production of gas and heat causes a backsurging of fluid into the wellbore.
    Type: Grant
    Filed: April 6, 1979
    Date of Patent: August 26, 1980
    Assignee: Shell Oil Company
    Inventors: Edwin A. Richardson, Ronald F. Scheuerman, David C. Berkshire
  • Acidizing reservoirs while chelating iron with sulfosalicylic acid
    Patent number: 4137972
    Abstract: The acidizing of a reservoir, particularly one that contains an asphaltenic oil, is improved by using an aqueous solution of strong acid which contains enough sulfosalicylic acid to prevent the formation of iron-asphaltenic solids.
    Type: Grant
    Filed: June 24, 1977
    Date of Patent: February 6, 1979
    Assignee: Shell Oil Company
    Inventors: William A. McLaughlin, David C. Berkshire