Inside BOP (IBOP), Kelly Valves Full Guide
The Inside BOP (IBOP) as gray valve is a back-pressure type valve (or float valve) that allows stripping operation using kelly / top drive or running drill pipe into the hole without mudflow upward through the valve. It can be stabbed and made up on the drill pipe only at very low flow rates. The best method is to stab and close the Full-Opening Safety Valve first, then install the Inside BOP if the decision is made to go back into the hole.
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