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:
Jun. 12, 1984
Filed:
May. 10, 1982
John V Fredd, Dallas, TX (US);
Otis Engineering Corporation, Dallas, TX (US);
Abstract
A method and apparatus for annulus flow systems in which a safety valve controls flow adjacent the packer and the safety valve is operated by control of tubing pressure exerting an upward force on the valve operator and an urging device such as a weight string of tubing exerting a downward force on the operator. In one form the control valve is a foot valve below the packer which is automatically closed by removal of the actuator. In other forms the control valve is removable with the tubing string and a separate foot valve may be provided below the packer, if desired. The system may be designed to close the safety valve in direct response to a reduction in pressure in the well annulus, or it may be designed to reduce or increase tubing pressure and close the safety valve in response to any well condition sensed at the surface which would include a reduction in annulus flow pressure. Provision is made for a pressure sensing instrument to be associated with the control valve and the control valve may be opened and closed by changing tubing pressure to obtain well data. In one form when the sensing instrument is removed the tubing is automatically closed. In another form after the sensing instrument is removed, a plug is run to close the lower end of the tubing.