API REPORT 88-17
API 14A Subsurface Safety Valve Research Study - Year 3
|Publication Date:||1 December 1989|
This report presents the findings and recommendations from the third year of an American Petroleum Institute (API) research study aimed at updating the Specification 14A Verification Test Procedure for surface-controlled subsurface safety valves (SCSSV). Specification 14A was formulated in 1973 to provide a meaningful specification for subsurface safety valve equipment. The specification has been periodically updated to remain current with the latest safety valve design innovations and down-hole environment in which the safety equipment must function.
In the preceding years of this research study, a world-wide survey of
oil and gas producers and subsurface safety valve manufacturers was
conducted to obtain information on subsurface safety valve performance
and the production well environment. The survey results indicated that
the 14A Verification Test Procedure for surface-controlled subsurface
safety valves needed updating to stay current with recent safety valve
developments and the ever-increasing severity of the down-hole
environment. The survey information was used as the basis for proposed
changes to the Verification Test Procedure. These proposed changes
were evaluated during laboratory testing, during Years 2 and 3, of
Draft wording of a revised Verification Test Procedure for SCSSVs was finalized in Year 3, following the completion of the lab evaluation of the proposed changes to the procedure. The draft wording is included in Appendix A of this report.
The knowledge gained through the industry survey and the lab evaluation of proposed changes to the test resulted in a revised Verification Test for SCSSVs that is more meaningful with respect to current field conditions. Some of the more significant recommended changes to the procedure included the following. The gas and water test flow rate ranges were broadened. Hydraulic control line resistance variation was added as part of the gas flow test. An elevated temperature test (maximum temperature of 180°F) of the valve seat and control system seals was added to both the Class 1 and Class 2 tests. Also, in the Class 2 test, the sand slurry recipe was changed to a more representative formulation (i.e., smaller sand particle size, 80 to 100 U.S. mesh, and less viscous slurry, 70 Marsh seconds) and the sand slurry circulation periods were reduced. The total number of open/close cycles on the valve closure mechanism was increased to 203, a number more representative of what a typical valve may experience during its operational life.
Also during Year 3, the Verification Test Procedure for