Newest Through-Flowline Retrievable Safety Valves for Subsea Completions

Abstract

Two new retrievable-ball-type safety valves are now available in the through-flowline (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 our RandD Dept. One valve is a balance-line valve with a fail-close leak protection feature. The other valve is a single-line, deep-set valve that allows installation at greater depths than previously achieved. They have tested successfully in test wells and test loops by the manufacturer and in two land test wells by the operators. The safety system packages for these valves currently are installed in two subsea wells, one in the North Sea and the other in the South China Sea. This paper discusses how the capabilities of subsea production are expanded by the development of a truly failsafe, balance-line, retrievable-ball valve and a deep-set, single-line ball valve that can be placed at or near the packer, below paraffin levels, or below the kickoff point.