Patent ID: 8381812
Filing Date: 2013-02-26
Classification: E21B

Abstract:
1. A well head barrier assembly comprising: a well head barrier; a well head joint between the well head barrier and a well head adapter, the well head joint having an internal passage extending between the well head adapter and the well head barrier; an instrument tube in the passage of the well head joint and extending into an internal chamber of the well head barrier; a primary pressure barrier formed by the instrument tube, the well head joint and the well head barrier; a tool configured to advance through a wall of the well head joint towards and into the passage, whereby advancing of the tool into the passage and against the instrument tube closes said passage and the instrument tube to provide a secondary pressure barrier, and the wall with the passage and to said well head joint includes a weakened section between an advancing end of the tool and the passage, wherein the weakened section is substantially thinner than any other section of the wall.