Patents by Inventor Johannes H. G. Surewaard

Johannes H. G. Surewaard 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).

  • Detecting outflow or inflow of fluid in a wellbore
    Patent number: 5168932
    Abstract: A method is provided for detecting outflow of fluid from an offshore wellbore to a surrounding earth formation or inflow of fluid from the formation of the wellbore. The wellbore is in fluid communication with a conduit extending between the wellbore and an offshore structure floating above the wellbore, which wellbore and conduit are at least partly filled with a body of fluid. Liquid is injected into the body of fluid at a first predetermined flowrate, and liquid is discharged from the body of fluid at a second predetermined flowrate. A variation of the content of the body of fluid is then determined.
    Type: Grant
    Filed: July 15, 1991
    Date of Patent: December 8, 1992
    Assignee: Shell Oil Company
    Inventors: Robert N. Worrall, Johannes H. G. Surewaard, Peter Oosterling