Patents Assigned to Gulf Research Institute
  • Patent number: 5233866
    Abstract: Test apparatus, and method for accurately and quickly measuring formation pressure, and permeability in oil and gas producing formations; especially low or high permeability formations. The test apparatus can be transported on a drill string, or cable. Preferably, it is employed as a component of a wireline test apparatus. The test apparatus includes, as part and parcel of the combination, an extended drawdown subassembly, or formation pressure test unit, directly associated with the tool flowline. By applying a very slow rate of pressure decrease in the tool flowline, the formation pressure and permeability can be quickly determined, generally during the first minute of testing. In high permeability and soft formations, the formation pressure is determined even if the seal is lost during the flowing period. In low permeability formations, corrections can be made for the supercharging effect using the data collected.
    Type: Grant
    Filed: April 22, 1991
    Date of Patent: August 10, 1993
    Assignee: Gulf Research Institute
    Inventor: Robert Desbrandes