| 摘要 |
An apparatus and method for shutting in a well in the event all other control equipment on the well fails to close and hold. The apparatus includes a lower and upper tubing head in which the tubing extends from the well upwardly through the lower head and into the upper head and sealingly engages both heads. A sealing and shear ram is positioned between the heads for shearing and sealing the tubing. The shear tubing is moved away from the shear rams after shearing to allow the rams to seal. The tubing is preferably supported from only one of the tubing heads. In one embodiment the tubing is supported initially from the upper head and after shearing the lower tubing portion moves downwardly to seat on the lower tubing head for allowing the rams to seal. In another embodiment the tubing is supported from the lower head and after shearing the upper portion of the tubing is raised to allow the shear rams to seal.
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