Drilling and Completions
Focused on Efficiency and Safety
The drill bit was still turning in the second exploration well when LLOG began ordering subsea trees. Nine of them, at roughly $7 million each. The purchase took more than confidence.
The development team was planning far ahead,
not only with the trees, but the wellheads,
casing and intelligent downhole systems.
Everything had to be ordered long before it
was needed in the field. It takes a tremendous
amount of planning; safety is paramount, but
beyond that, planning mistakes can quickly
break the bank.
Standards Reduce Risk
LLOG’s drilling team was sure it could use the
equipment that was ordered for Delta House,
mainly because the company has standardized
its wells. Most LLOG deepwater developments,
for example, use the same horizontal trees. Any
trees that are not needed for Delta House can
be used in other LLOG fields. Standardization
adds flexibility, and it also makes it easier for
suppliers to respond to urgent requests.
“Any benefit we may give up in terms of a
perfect fit for one application, we gain back in
terms of responsiveness from our suppliers
and the ability to move a project forward,” says
Joe Leimkuhler, drilling vice president. “With
a horizontal tree, I can get on a well with
any riser and BOP stack combination of any
deepwater rig in the Gulf of Mexico.”
There are tradeoffs, of course. Horizontal trees
are better for major well interventions because
you can gain full access to the wellbore
without pulling the tree, but if all you need
is lighter diagnostic work, a vertical tree has
some advantages. LLOG’s subsea manifolds
are also standardized. Instead of designing
a new manifold for each field, LLOG uses a
standard manifold that’s good for four wells.
To shorten the feld development time, wellheads were
ordered far in advance.