Newest TFL Retrievable Safety Valves for Subsea Completions

ABSTRACT Two new retrievable ball type safety valves are now available in the TFL (pumpdown) configuration. These valves offer greater depths in a more simplified configuration to operators planning subsea completions. They were developed at the request of major producers for use in the North Sea and Southeast Asia. Design of these new valves began -in 1977 and early 1978 by engineers from Otis' Research and Development Department. One valve is a balance line valve with a fail-close leak protection feature. The other valve is a single line deep set valve which allows installation at greater depths than previously achieved. They have been successfully tested in test wells and test loops at the manufacturer and in two land test wells by the operators. The safety system packages for these valves are currently installed in six subsea wells – five in the North Sea and the other in the South China Sea. The material presented in this paper shows how the capabilities of subsea production are expanded by the development of a truly fail safe balance line retrievable ball valve and a deep set single line ball valve which can be placed at or near the packer, below paraffin levels, or below the kickoff point.