Patents Represented by Attorney Phillip G. Woo
  • Patent number: 6838532
    Abstract: The present invention is a process for transitioning from a first polymerization catalyst system to a second polymerization catalyst system incompatible with the first polymerization catalyst system in a gas-phase reactor. The novel process comprises conducting a first polymerization reaction using a first polymerization catalyst system; stopping the first polymerization reaction; removing the contents of the first polymerization reaction from the reactor while maintaining a substantially closed system; then, in the substantially closed system, introducing a substantially contaminant free seedbed into the reactor; introducing a second feed system and a second catalyst system into the reactor; and conducting a second polymerization reaction.
    Type: Grant
    Filed: October 10, 2003
    Date of Patent: January 4, 2005
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Thomas Redden Veariel, George Varcelia Yenetchi, Sandy Clay Hinds, Diwalker Singh, Thierry Polchlopek
  • Patent number: 6800193
    Abstract: The invention describes a method for decreasing the viscosity of crude oils and residuum utilizing a combination of thermal and acidic treatment. Further, the invention describes a method for making a water-in-oil emulsion, or a solids-stabilized water-in-oil emulsion with a reduced viscosity. The emulsion can be used in enhanced oil recovery methods, including using the emulsion as a drive fluid to displace hydrocarbons in a subterranean formation, and using the emulsion as a barrier fluid for diverting flow of fluids in the formation.
    Type: Grant
    Filed: March 28, 2001
    Date of Patent: October 5, 2004
    Assignee: ExxonMobil Upstream Research Company
    Inventor: Ramesh Varadaraj
  • Patent number: 6559253
    Abstract: The invention is directed to olefin polymerization processes using bridged hafnocene catalyst complexes comprising highly substituted noncoordinating anions that are surprisingly stable under high temperature olefin polymerization processes such that olefin copolymers having significant amount of incorporated comonomer can be prepared with high molecular weights. More specifically, the invention is a polymerization process for ethylene copolymers having a melt index of about 0.87 to about 0.930 comprising contacting, under homogeneous polymerization conditions at a reaction temperature at or above 140° C. to 225° C.
    Type: Grant
    Filed: July 10, 2001
    Date of Patent: May 6, 2003
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Donna J. Crowther, Bernard J. Folie, John F. Walzer, Jr., Rinaldo S. Schiffino