Patents by Inventor David R. Thigpen

David R. Thigpen 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).

  • Iron hydroxide removal method
    Patent number: 5223153
    Abstract: Calcium silicate filter aids have been found to be effective to remove colloidal iron suspensions from aqueous streams without plugging filters. Calcium silicate filter aid is made by heating diatomaceous earth with hydrous lime.
    Type: Grant
    Filed: August 14, 1992
    Date of Patent: June 29, 1993
    Assignee: Shell Oil Company
    Inventors: Jimmie B. Lawson, David R. Thigpen
  • Preformed surfactant-optimized aqueous alkaline flood
    Patent number: 5068043
    Abstract: An aqueous alkaline flood for recovering oil from a reservoir containing acidic oil is improved by adding to the injected aqueous alkaline solution both a stoichiometric excess of the alkaline material and a kind and amount of preformed cosurfactant material that increases the salinity of that solution so that, in contact with the oil in the reservoir, it will form a surfactant system having a salinity requirement which minimizes the interfacial tension between it and the oil.
    Type: Grant
    Filed: August 9, 1989
    Date of Patent: November 26, 1991
    Assignee: Shell Oil Company
    Inventors: David R. Thigpen, Jimmie B. Lawson, Richard C. Nelson
  • Staged preformed-surfactant-optimized aqueous alkaline flood
    Patent number: 4502541
    Abstract: Oil is recovered from an acidic oil reservoir by injecting an alkaline, saline, aqueous solution containing proportions of preformed cosurfactant which are decreased as increasing amounts of the solution are injected.
    Type: Grant
    Filed: November 7, 1983
    Date of Patent: March 5, 1985
    Assignee: Shell Oil Company
    Inventors: Jimmie B. Lawson, David R. Thigpen
  • Recovering oil by injecting aqueous alkali, cosurfactant and gas
    Patent number: 4493371
    Abstract: A process of recovering oil from a subterranean reservoir in which the oil is acidic but forms monovalent cation soaps of only relatively low interfacial activity when reacted with aqueous alkaline solutions, comprises displacing the oil toward a production location with a mixture of gas and cosurfactant-containing aqueous alkaline solution.
    Type: Grant
    Filed: July 29, 1983
    Date of Patent: January 15, 1985
    Assignee: Shell Oil Company
    Inventors: Joseph Reisberg, Lawrence J. Bielamowicz, David R. Thigpen
  • Process for stimulating a well with a saline surfactant sulfate, alkanol and acid system
    Patent number: 4279305
    Abstract: The injectivity of an oil-containing reservoir is increased by injecting successive portions of a solution or slightly turbid dispersion of reservoir-tailored amounts of polyalkoxyalcohol sulfate surfactant and lower alkanol in highly saline aqueous liquid and a reservoir acidizing solution.
    Type: Grant
    Filed: May 27, 1980
    Date of Patent: July 21, 1981
    Assignee: Shell Oil Company
    Inventors: Randolph H. Knapp, Jimmie B. Lawson, Joseph Reisberg, David R. Thigpen, Harold J. Hill
  • Preparing an aqueous alkaline solution for recovery of oil from a reservoir containing hard water
    Patent number: H475
    Abstract: An aqueous alkaline oil recovery fluid containing monovalent salt, and, optionally, preformed cosurfactant, is improved by using a mixture of alkaline silicate and carbonate salts in specified proportions as the alkaline material.
    Type: Grant
    Filed: October 24, 1986
    Date of Patent: June 7, 1988
    Assignee: Shell Oil Company
    Inventors: Jimmie B. Lawson, David R. Thigpen, Richard C. Nelson, Jeffery G. Southwick