... to prevent well blowout effectively and realize sa single ram BOPAnnular BOP is an important part of ... ram BOP and also independently. 1, It can seal any size of annular space with a kind of ... there is no drilling tool in hole, it can seal the well head completely. 3, When the well ... happens during drilling, coring or welllogging, it can seal the annular spaces between Kelly, coring tools, cable, ...