scope:

ABSTRACT

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 nine previously-certified subsurface safety valves.The lab evaluation was conducted at Southwest Research Institute's (SwRI) Safety and Pollution Prevention Equipment (SPPE) Safety Valve Test Facility.

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 subsurface-controlled subsurface safety valves (SSCSVs) was reviewed to determine if it required updating. Changes were suggested to make the procedure up-to-date with regard to current field conditions and consistent with the newly-revised Verification Test Procedure for SCSSVs. The suggested changes included increasing the number of open/close cycles on the valve closure mechanism and reducing the duration of the liquid circulation periods. It was also recommended that the Class 2 sand slurry formulation be changed to that proposed for the SCSSV test and that the test pressures be changed to correspond to those proposed for the SCSSV test. A laboratory evaluation of these recommended changes was not initiated during Year 3.