Well safety system
A well safety system is claimed for controlling the flow of fluid through well conduits. The system includes a surface controlled subsurface safety valve made up as part of a tubing string extending from the well surface to a subsurface formation within a casing string. A packer, installed below the safety valve, forms a fluid tight seal between the tubing and casing to direct fluid from below the packer into the tubing. The safety valve contains lateral passageways which allow communication of fluid from the bore of the safety valve to the annulus between the tubing and casing above the packer. A valve actuator is releasably secured within the upper portion of the safety valve and forms a fluid tight seal between control fluid pressure in the tubing string above the safety valve and formation fluid pressure in the tubing string below the safety valve. The safety valve can be locked open when control pressure is increased above a preselected value and then released. The safety valve can be unlocked by returning control pressure to another preselected value. The valve actuator allows liquids to be injected from the surface to below the safety valve to kill the well. The tubing and seals within the valve actuator can be pressure tested when the valve actuator is initially installed within the safety valve without opening the safety valve.
- Assignee:
- Otis Engineering Corp
- Patent Number(s):
- US 4276937
- OSTI ID:
- 6148082
- Resource Relation:
- Patent File Date: Filed date 7 Feb 1979
- Country of Publication:
- United States
- Language:
- English
Similar Records
Well bore apparatus with annulus pressure releasable tubing seal unit
Electrically operated well completion apparatus and method