| 摘要 |
A blowout preventer for use in combination with a deep well pump during steam injection, comprises a hollow cylindrical nipple having a top and bottom surface and a through cylindrical bore of diameter D1. A cylindrical mandrel is partially received in the cylindrical bore provided in the nipple. The cylindrical mandrel has a first diameter portion of diameter D2, a second diameter portion of diameter D3 and a third diameter portion of diameter D4 wherein D2>D1>D3>D4 such that the first diameter portion abuts the bottom surface of the nipple upon an excess in well head pressure so as to prohibit blowout. An elastically deformable seal is carried on the third diameter portion of the mandrel for sealing the mandrel within the cylindrical bore of the hollow cylindrical nipple, in order to prevent steam leakage during the steam injection process. |
