The TRC-II tubing-retrievable, charged safety valve is a surface-controlled subsurface valve that uses a gas-spring design with gas-powered actuators that allow installation at depths significantly deeper than conventional spring type designs. Because these valves can be run at greater depths, they can be positioned below the hydrate- or paraffin-deposit regions to increase operating efficiency.
The compact design of TRC-II valves incorporates laboratory- and field-proven Schlumberger technologies, including rod piston actuators that are insensitive to tubing pressure and require substantially lower hydraulic operating pressures. Two separate piston systems connected to individual control lines provide complete operating redundancy. Either system is fully capable of operating the valve and incorporates a minimum number of critical, dynamic, and static seals; a 5-um control-fluid-filter; and disconnect rod pistons to ensure fail-safe operation.
The valve features a rugged flapper-closure system and meets a leakage acceptance criterion substantially more stringent than API and ISO specifications.