The Hydril Pressure Control Subsea Stack Test Valve (SSTV™) replaces the traditional practice of running and setting a BOP test plug, potentially saving a great deal of tripping time.  The SSTV is designed to be used in the lowest cavity of a BOP stack and seals around the drillstring in the well. The SSTV comprises a ram blowout preventer that seals in the downward direction. The BOP test pressure applied above the rams energizes the downward-facing “top seal,” while the variable bore packer is bi-directional. This arrangement allows pressure to be applied above the SSTV to test all the cavities above it, while isolating the well from the test pressure. In the SSTV cavity design, what normally is referred to as the “top seal” is actually a bottom seal, effecting a seal on what is usually a wearing surface. This configuration enables rig crews to complete testing in about one hour, without pulling the drill pipe and setting a test plug. The test valve:

• Is designed for a minimum of one year of operation with no downtime.
• 364 open/close cycles
• 52 wellbore pressure tests
• Has been used successfully by leading drilling contractors
• Works with any rig, even if the SSTV is the only Hydril Pressure Control equipment on it.
• Uses a Hydril Pressure Control variable ram that seals off 4-1/2" to 7" mandrels
• Can be reconfigured in the field to be run as a conventional ram BOP cavity.
• Is designed in accordance with API 16A and NACE MR0175