Drilling media injection for rotating blowout preventors

摘要

Improvements in the operation of a rotating blowout preventor. The rotating head assembly of a rotating blowout preventor includes a stripper rubber which has an upper annular member attached to the lower annular end of a metal support member. The support member extends upwardly into fixed relationship respective to part of the rotating head. The stripper rubber is in the form of an annular body which has an axial passageway formed therethrough for telescopingly receiving a rotating member in sealed relationship therewith. The outer circumferentially extending lower wall surface of the rubber rotatably engages the lower marginal inside wall surface of a fixed washpipe. The present invention provides a positive pressure of drilling media, or drilling media admixed with lubricant, at the interface formed between the outer rubber surface and the inner surface of the washpipe. In another form of the invention, the drilling media flows into the bearing chamber of the rotating head and then into the interface between the rubber and washpipe, so that debris cannot enter either part of the RBOP.