SUB-SURFACE WELL BLOWOUT PREVENTER OPERATED MECHANICALLY FROM THE SURFACE

摘要

Well flow control apparatus includes a bottom hole pumping string, a stuffing box in the well to seal off about the pumping string and carried by an inner casing string, and an outer casing string. Controlled displacement of the pumping string effects a pack-off between a plug on the pumping string and tubing suspended by the outer casing string below the inner casing string; and the inner casing string, stuffing box, pumping string, plug and bottom hole pump may all be retrieved while the well is secured against blowout.