Patents by Inventor Thomas L. Ashcraft, Jr.

Thomas L. Ashcraft, Jr. 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: 5503761
    Abstract: A synthetic ester base stock having reduced deposit formation which comprises the reaction product of technical pentaerythritol and a mixture of carboxylic acids. The mixture of carboxylic acids comprises (1) at least one C.sub.8 -C.sub.10 carboxylic acid having 6 or less reactive hydrogens, (2) at least one C.sub.5 -C.sub.7 carboxylic acid having 6 or less reactive hydrogens and (3) at least one C.sub.6 -C.sub.10 carboxylic acid having 6 or more reactive hydrogens.
    Type: Grant
    Filed: August 2, 1994
    Date of Patent: April 2, 1996
    Assignee: Exxon Research & Engineering Co./Hatco Corp.
    Inventors: Thomas L. Ashcraft, Jr., Paul J. Berlowitz, Max J. Wisotsky, Dale D. Carr, Thomas G. Schaefer
  • Patent number: 4959490
    Abstract: A process for manufacturing monosulfonated alkylphenol polyalkylene oxide sulfonates is disclosed. The process produces the monosulfonated alkylphenol polyalkylene oxide sulfonates by a combination of sulfonation to produce a sulfate/sulfonate dianion, followed by a displacement of the sulfate to produce a disulfonate. The process produces a commercially viable disulfonate, which has a wide variety of commercial uses.
    Type: Grant
    Filed: November 14, 1988
    Date of Patent: September 25, 1990
    Assignee: Exxon Production Research Company
    Inventors: Margaret B. Parnell, Thomas L. Ashcraft, Jr., Kenneth M. Webber
  • Patent number: 4828032
    Abstract: A method for recovering oil from a subterranean formation is disclosed wherein an aqueous surfactant solution is injected into the formation to reduce the mobility of gas in a gas-flooding process. The gas may include hydrocarbon gas, inert gas, carbon dioxide, and steam. The surfactant is represented by the general formula ##STR1## where R is a linear or branched chain alkyl group with n carbon atoms wherein n ranges from 0 to about 18, except that if the gas is steam n ranges from about 9 to about 30;x ranges from 0 to about 20 and y ranges from 0 to about 20, provided x+y does not exceed about 20;R' is a linear or branched chain alkyl group with m carbon atoms wherein m ranges from 0 to 4, except that if the gas is steam m ranges from 1 to 4, with the proviso that the sum of x+y+m is at least one; andeach M.sup.+ is a cation.
    Type: Grant
    Filed: December 7, 1988
    Date of Patent: May 9, 1989
    Assignee: Exxon Production Research Company
    Inventors: Gary F. Teletzke, Thomas L. Ashcraft, Jr., Ronald L. Reed
  • Patent number: 4452708
    Abstract: An oil recovery method is disclosed which uses a particular class of alkylaryl sulfonate surfactants. The surfactants are derived from an extracted aromatic feedstock consisting essentially of benzene, toluene, xylenes, and lesser amounts of ethylbenzene, trimethylbenzenes, and tetramethylbenzenes. The aromatic feedstock is then alkylated with linear .alpha.-olefins to favor second-carbon attachment, and sulfonated to result in surfactants having high oil solubilization parameters and whose phase behavior is substantially independent of temperature over 120.degree.-250.degree. Fahrenheit.
    Type: Grant
    Filed: February 18, 1982
    Date of Patent: June 5, 1984
    Assignee: Exxon Production Research Co.
    Inventors: Haven S. Aldrich, Thomas L. Ashcraft, Jr., Maura C. Puerto, Ronald L. Reed
  • Patent number: 3977471
    Abstract: A method is disclosed for recovering oil from a subterranean oil-bearing formation wherein a liquid solution in injected into and driven through the formation and oil is recovered from the formation. The liquid solution contains an effective amount of a surface-active agent having the general formula: ##EQU1## or ##EQU2## wherein R.sub.1 is a benzene, toluene, or xylene radical having a linear or branched alkyl substituent containing from 6 to 24 carbon atoms;R.sub.2 is an alkyl, cycloalkyl, alkene or aryl radical containing up to 8 carbon atoms;R.sub.3 is a hydrogen atom, a hydroxyl radical, or an aliphatic radical containing from 1 to 8 carbon atoms;n has a value of 2 or 3;m has an average value of from 1 to 20; andX is a cation.
    Type: Grant
    Filed: September 26, 1975
    Date of Patent: August 31, 1976
    Assignee: Exxon Production Research Company
    Inventors: Walter W. Gale, Rhoderick K. Saunders, Thomas L. Ashcraft, Jr.
  • Patent number: 3946812
    Abstract: One embodiment includes an oil recovery process, more particularly a secondary or tertiary type crude oil recovery process utilizing a drive fluid to move a displacing fluid through a subterranean formation wherein the displacing fluid displaces crude oil therefrom and is driven through the formation by means of the drive fluid. The crude oil recovery process is improved by utilizing as the drive fluid a thickened, transparent, aqueous solution of a water-soluble sulfated, polyethoxylated C.sub.10 -C.sub.18 primary alcohol or alkylated phenol. The displacing fluid is generally an aqueous surfactant solution, a miscible displacing medium or most preferably a microemulsion. In a further embodiment, the water-soluble, polyethoxylated C.sub.10 -C.sub.18 primary alcohol or alkylated phenol is employed as a mobility control agent in a waterflood thereby increasing the sweep efficiency thereof.
    Type: Grant
    Filed: March 12, 1975
    Date of Patent: March 30, 1976
    Assignee: Exxon Production Research Company
    Inventors: Walter W. Gale, Thomas L. Ashcraft, Jr., Rhoderick K. Saunders