Claims
- 1. A method of controlling operation of a well pressure safety valve adapted to be located at a subsurface location in a well tubing for controlling flow of well fluids to the surface through the bore of the well tubing including the steps of:
- establishing a preselected ambient well fluid pressure for sensing by the safety valve to enable flow through the bore of the well tubing to the surface;
- sensing with the safety valve both increasing and decreasing pressure changes in the well fluid pressure in the well tubing from the established preselected well fluid pressure for effecting operation of the safety valve; and
- closing the safety valve to block flow of well fluids at the subsurface location responsive to either of both sensed pressure changes in the well tubing.
- 2. The method as set forth in claim 1, including the step of:
- increasing the well fluid pressure sensed by the safety valve for closing the safety valve by decreasing the flow of well fluids from the bore of the well tubing.
- 3. The method as set forth in claim 1, including the step of:
- decreasing the well fluid pressure sensed by the safety valve for closing the safety valve by increasing the flow of well fluids from the bore of the well tubing.
- 4. The method as set forth in claim 1, including the step of:
- blocking flow of well fluids from the bore of the well tubing for increasing the well fluid pressure sensed by the safety valve for closing the safety valve.
- 5. The method as set forth in claim 1, including the steps of:
- increasing the pressure of the well fluids in the bore of the well tubing above the closed safety valve to exceed the pressure of the well fluids in the bore of the well tubing below the safety valve; and
- decreasing the pressure of the well fluids in the bore of the well tubing above the safety valve to the established preselected pressure for opening the safety valve to enable flow of well fluids through the bore of the well tubing.
- 6. A method of operating a well fluid ambient pressure responsive subsurface safety valve disposed in a well tubing to control the flow of well fluids through the bore of the tubing to control the flow of well fluids through the bore of the tubing including the steps of:
- sensing with the safety valve both increasing and decreasing pressure changes in the well fluid pressure in the bore of the well tubing from a preselected ambient well fluid pressure for operating the safety valve; and
- closing the safety valve to block flow through the bore of the well tubing at the sursurface location responsive to either sensed pressure change in the bore of the well tubing.
- 7. The method as set forth in claim 6, including the step of:
- increasing the well fluid pressure sensed by the safety valve for closing the safety valve by decreasing the flow of well fluids from the bore of the well tubing.
- 8. The method as set forth in claim 6, including the step of:
- decreasing the well fluid pressure sensed by the safety valve for closing the safety valve by increasing the flow of well fluid from the bore of the well tubing.
- 9. The method as set forth in claim 6, including the step of:
- blocking flow of well fluids from the bore of the well tubing for increasing the well fluid pressure sensed by the safety valve for closing the safety valve.
- 10. The method as set forth in claim 6, including the steps of:
- increasing the pressure of the well fluids in the bore of the well tubing above the closed safety valve to exceed the pressure of the well fluids in the bore of the well tubing below the safety valve; and
- decreasing the pressure of the well fluids in the bore of the well tubing above the safety valve to the established preselected pressure for opening the safety valve to enable flow of well fluids through the bore of the well tubing.
Parent Case Info
This is a division of application Ser. 1975, 566,202 filed Apr. 9, 1975 now Pat. No. 3,987,849 which is a continuation of application Ser. No. 399,455, filed Sept. 21, 1973 now abandoned which is a division of application Ser. No. 214,679, filed Jan. 3, 1972 and which issued on Jan. 29, 1974 as U.S. Pat. No. 3,788,594.
US Referenced Citations (5)
Divisions (2)
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Number |
Date |
Country |
Parent |
566202 |
Apr 1975 |
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Parent |
214679 |
Jan 1972 |
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Continuations (1)
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Number |
Date |
Country |
Parent |
399455 |
Sep 1973 |
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