The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 20, 1983
Filed:
Jul. 13, 1981
Michael E McMahan, Duncan, OK (US);
Halliburton Company, Duncan, OK (US);
Abstract
A spherical valve member type having a drill pipe tester valve and a moving apparatus to provide for moving the spherical valve member axially relative to the housing between its said open and closed positions, thereby permitting downward forces exerted upon the spherical valve member in its said closed position due to fluid pressure in the well test string above the spherical valve member, to be transmitted substantially entirely to the housing through the engagement of the downward facing surface of the lower valve seat structure and the upward facing surface of the housing. A latch device is provided for latching the spherical valve member in its closed position as the well test string is lowered into the well and for subsequently releasing the spherical valve member and allowing it to move to its open position when the well test string is finally positioned within the well. A resilient means is provided to prevent movement of the spherical valve member to its open position until a predetermined force is applied to the tester valve. Upon picking up the well test string the latching device provides a safety valve feature by moving the spherical valve member back to its closed position.