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30" LEVELING PILE (4

PLACES)

SALES

RISER
WELLHEAD
BASE
RECEPTACLE (TYP)

Figure 6.38 - 21-well unitized template. (Courtesy Vetco)

The wellhead receptacles allow wells to be drilled using standard subsea

drilling techniques. During template fabrication, the guideposts for the wellhead

receptacles are held in position at top and bottom during welding to ensure

verticality and critical spacing. To install the wellhead receptacles, a fixture is run

down over the four guideposts of the slot where the receptacle is to be placed. The

center of the fixture has an outer profile that matches the inner profile of the

receptacle. A tapered section below the receptacle centralizes it on its support

beams. When the receptacle is landed and centralized, it is welded to the large

support beams of the template.

There is likely to be quite a time lag between setting the template and

completing the TLP; consequently, a number of preliminary operations are carried

out by a floating drilling vessel (fig. 6.39) including:

1. Setting and leveling the unitized template

2. Connecting the sales pipeline

3. Setting the anchor template and piles for mooring the TLP

4. Drilling a number of the subsea template wells

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