API REPORT 87-17
API 14A Subsurface Safety Valve Research Study - Year 2
|Publication Date:||1 December 1988|
This report presents the findings and recommendations from the second year of an American Petroleum Institute (API) research study aimed at updating the API 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 is periodically updated so that it continues to address the latest technological developments in safety valve design as well as the ever-changing down-hole environment in which the safety equipment must function.
At the end of the first year of this study, Southwest Research Institute (SwRI) recommended that several of the existing elements of the Verification Test Procedure be updated and that new test elements also be included. The suggested changes were based on the findings from a Year 1 industry survey. The suggested changes to the test procedure included increasing the number of open/close cycles on the test valves, expanding the range of gas and liquid test flow rates to more closely match field conditions, adding hydraulic control line resistance in the gas flow test stand control system to more realistically simulate the long control lines typically seen in field installations, modifying the sand slurry formulation used in Class 2 testing to be more representative of field conditions, adding seal leak testing at elevated temperatures, and adding a drift test to the Class 1 test.
In the second year of the study, a laboratory evaluation of the suggested changes to the Verification Test Procedure was conducted at the SwRI safety valve test facility on a limited number (three) of surface-controlled subsurface safety valves. Also, the Year 1 industry survey was expanded to include oil and gas producers operating primarily outside of the United States. The purpose of expanding the survey was, first, to determine how operating conditions in the United States differ from the rest of the world and, second, to allow SwRI to suggest changes to the Verification Test based on data collected for operations world-wide.
The Year 2 laboratory evaluation of the revised Verification Test
Procedure using three previously-certified