Definition(s)
Inside Blowout Preventer (IBOP)
A device that can be installed in the drill string that acts as a check valve allowing drilling fluid to be circulated down the string but prevents back flow.
Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global Standards
Inside BOP
A device that can be installed in the drill string that acts as a check valve allowing drilling fluid to be circulated down the string but prevents back flow.
Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards