Patents by Inventor Donald L. Purvis

Donald L. Purvis 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: 7207386
    Abstract: A method of hydraulically fracturing a hydrocarbon-bearing subterranean formation ensures that the conductivity of water inflow below the productive zone of the subterranean formation is reduced. The method consists of two principal steps. In the first step, a fracture in and below the productive zone of the formation is initiated by introducing into the subterranean formation a fluid, free of a proppant, such as salt water, fresh water, brine, liquid hydrocarbon, and/or nitrogen or other gases. The proppant-free fluid may further be weighted. In the second step, a proppant laden slurry is introduced into the subterranean formation which contains a relatively lightweight density proppant. Either the fluid density of the proppant-free fluid is greater than the fluid density of the proppant laden slurry or the viscosity of the proppant-free fluid is greater than the viscosity of the proppant laden slurry.
    Type: Grant
    Filed: June 9, 2004
    Date of Patent: April 24, 2007
    Assignee: BJ Services Company
    Inventors: Harold Dean Brannon, William Dale Wood, Donald L. Purvis, Allan Ray Rickards, Christopher John Stephenson
  • Patent number: 6367548
    Abstract: Methods and compositions for stimulating multiple intervals in wells by diverting well treatment fluids into multiple intervals by alternately displacing diverting agent from the annulus into a subterranean formation and displacing treatment fluid from a tubing string into the subterranean formation.
    Type: Grant
    Filed: March 3, 2000
    Date of Patent: April 9, 2002
    Assignees: BJ Services Company, Ocean Energy Resources, Inc.
    Inventors: Donald L. Purvis, David D. Cramer, David D. Smith, Douglas L. Walton