Blowout preventer cleaning tool

Abstract

A BOP cleaning tool includes a first pipe section with a through central channel and radial channels to external fins, with nozzles for flushing fluid from the central channel out into a BOP bore for washing cavities in the BOP bore, the central channel provided with a flow control sleeve provided with holes, the flow control sleeve displaceable from a radially closed initial first closed position to a second position with the holes aligned with the inner radial channels for starting flushing through the nozzles, and further displaceable to a radially closed third position with the holes out of alignment with the inner radial channels for halting the flushing through the nozzles. The flow control sleeve is displaceable from the first, initial position by a first dart dropped into the first pipe section and stopping in a first seat in the flow control sleeve below the holes, thereby closing the central channel, building pressure in the central channel, displacing the flow control sleeve to the second position and redirecting pipe flow to the nozzles. Flow control sleeve is displaceable from the second position to the third, closed position by a second dart dropped into the first pipe section and stopping at the first dart, the second dart blocking the holes thereby building pressure in the first pipe section, further displacing the flow control sleeve to the third position triggering a release mechanism for the first seat to release the first dart and the second dart.