Blowout Preventer Test Tool : A tool to allow pressure testing of the blowout preventer stack and accessory equipment by sealing the wellbore immediately below the stack. (RP 53)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}