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wellhead housing. It also provides final guidance for drilling tools, BOP stack, and
completion tree if necessary. The gimballed interface between the PGS and TGB
permits landing when misaligned up to 10° horizontally and ensures correct
alignment of the guide posts and conductor housing during installation. The 10-ft
guide posts on 6-ft radius may be fitted with a special post top for remote
guideline connection.
Figure 6.16 - Permanent guide base and wellhead housing on TGB.
(Courtesy Vetco)
Guidelines are trapped at the top and bottom of each post. Tension to
maintain parallel guidelines is less critical in shallow-water installations. But for
installation in, say, 1,000 ft of water, it is recommended that each guideline be
adjusted and hydraulically maintained at 2,000 lb plus the weight of the lines for
running tool operations and BOP or (tree) installation. This design provides for
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