Patents Assigned to Cook Testing Co.
  • Patent number: 4022273
    Abstract: An apparatus for controlling flow from a producing zone through a tubing string and through a bypass into the annulus between the tubing string and casing, the apparatus including a production flow tube and bypass tube extending through a packer which is set by fluid pressure supplied through the tubing string. A safety valve and sleeve assembly is positioned by wire line after the packer is set, the sleeve including a bypass control valve. The tubing string may carry a pump and electric motor and the bypass may receive encased conductors for the motor. The safety valve sleeve assembly includes fluid pressure responsive means for holding the safety valve in its open position, and a small pressure fluid line extends to the well mouth. Drop in pressure in the fluid line, either by control at the well mouth or by damage to the pressure fluid line, permits a spring to close the safety valve against upward flow of well fluid, and also to close the bypass control valve.
    Type: Grant
    Filed: October 10, 1975
    Date of Patent: May 10, 1977
    Assignee: Cook Testing Co.
    Inventor: Anil Marathe
  • Patent number: 3981360
    Abstract: A well tubing drain including a ported mandrel interposed in the tubing string of a pumping well, and a sleeve initially covering and sealing the mandrel ports, the sleeve being subject to a predetermined internal fluid pressure applied through the ports to shear a retainer pin and cause motion of the sleeve to open the ports.
    Type: Grant
    Filed: July 30, 1975
    Date of Patent: September 21, 1976
    Assignee: Cook Testing Co.
    Inventor: Anil Marathe