Patents by Inventor BY First City National Bank, executor

BY First City National Bank, executor 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).

  • Clay-free wellbore fluid
    Patent number: 4140639
    Abstract: A clay-free, i.e., non-argillaceous brine wellbore fluid having unstructured viscosity and improved water loss properties from an additive composition present in an amount of 0.1 to 3 weight % based on wellbore fluid and consisting essentially of 15 to 95 weight % of guar gum or hydroxyalkyl guar gum and 5 to 85 weight % of a water soluble salt, preferably alkaline earth salt of lignosulfonate.
    Type: Grant
    Filed: February 28, 1977
    Date of Patent: February 20, 1979
    Assignee: Brinadd Company
    Inventors: Jack M. Jackson, deceased, by Betty A. Jackson, executrix, BY First City National Bank, executor