DEEPWATER CASE STUDIES
plies to our partners, we have always pushed
for local people and local industry to share
the prosperity of major finds such as TEN.
At the same time, the Ghanaian government
and regulator have displayed equal drive
to see increased local participation. For
these reasons we asked each of our major
contractors to include local content plans
in their tenders and made them part of our
contracts. For example, FMC Technologies,
which was awarded the contract for the subsea production systems, has assembled and
tested the subsea trees for TEN at their facility in Ghana which has a predominantly
Other examples are the new Sekondi fabrication yard we used with MODEC and Technip to build piles and structural components
for TEN’s subsea architecture; and the Takoradi yard where Subsea 7 has manufactured a
complex gas export manifold which will soon
be installed on the seabed – a full year ahead
of schedule. This will allow TEN’s gas to mix
with Jubilee gas being exported to the Ghanaian shore. MODEC also used local companies
to build components that were sent to Singapore and installed on the FPSO.
Doing this work in-country builds capacity
and enables knowledge transfer to Ghana. We
supplemented these efforts with a second-ment program which saw employees from the
GNPC and Petroleum Commission of Ghana
join our project teams in London, Singapore,
Paris, and Houston to gain news skills and experience.
Of fshore: Did MODEC win the contract to
supply the weather-vaning, turret-moored
FPSO based partly on the partners’ experience working with the company on the Jubilee floater?
Hughes: Clearly this formed part of our
thinking, but they still had to go through
the process of bidding. All bidders had to
consider our requirements and enter a year-
long design competition which required
extensive engineering and planning work to
support their bids. MODEC emerged suc-
cessful from this process.
After winning the contract, MODEC bought
and converted a VLCC tanker in Singapore and
the resultant FPSO Prof. John Evans Atta Mills,
named after the late Ghanaian president who
facilitated first oil from Jubilee, reached Ghana
this March. It was then moored via nine chains
connected to suction piles, all built in Ghana,
at the TEN location. Intense planning was necessary to anchor the FPSO in the optimum
position to connect to the extensive network of
subsea equipment needed for the 24 wells that
will ultimately be drilled in the field.
On completion of the mooring and hook up
of flowlines and controls, the vessel underwent an extensive commissioning and testing
process. First oil was produced on Aug. 17.
We will soon begin injecting associated gas
into the Ntomme reservoir, and then next
year gas export to the shore will begin.
Offshore: Is development drilling on track?
Hughes: All is on track with our plans for
first oil. Our development plan is for a total of
24 wells, 10 of which were required, and will be
delivered, by first oil. The well stock is a combination of re-used E&A wells and new wells.
There is a maritime border dispute between
the governments of Ghana and Côte d’Ivoire
and until the resolution of this process, we
cannot initiate any new drilling. However, we
had already completed the drilling of our first
oil wells when the drilling hiatus was imposed.
The border dispute will be resolved by ITLOS
[International Tribunal of the Law of the Sea]
in 2017, after which we hope to resume our de-
velopment plan. Though not ideal, this drilling
hiatus does mean that when we resume drill-
ing it will be at the lower rig rates we now see
due to the change in market conditions experi-
enced over the last year.
Of fshore: Will all the subsea equipment be
in place before start-up?
Hughes: Everything apart from the gas
export manifold is in place, and we expect
to install the manifold in September, nearly a
year ahead of plan. FMC should deliver the
last of the subsea trees next March, making
them available for when we resume drilling.
Our wells feature smart completions which
allow us to monitor and control individual
Offshore: Can you provide details of the production capacity and offtake arrangements?
Hughes: The facilities can handle up to
a nominal 80,000 b/d of oil, with storage
capacity of 1. 7 MMbbl. Every two weeks
during the plateau period, one cargo of 1
MMbbl will leave the facility which is of similar oil quality to Jubilee. We are also hopeful
that we will be ready to export gas in 2017
— much earlier than planned.
Of fshore: Following the oil price ‘shock,’
did the partners and the Petroleum Commission get together to find ways of bringing
the project costs down?
Hughes: Yes. When we sanctioned the
project, our contracting strategy was to secure capacity and minimize risk and exposure. Some of that required ‘lump sum’ contracts where the price is fixed up front so we
were limited in what we could do here. But
where costs were not fixed, we have achieved
some savings. We will not finalize our numbers for a little while yet, but our capital costs
to first oil will come in under the $4-billion figure we approved at sanction. And of course,
the TEN fields will be operating for many
years to come so we are looking hard at our
operating costs and the synergies we can
achieve from a two-field operation.
Of fshore: Will Tullow have to relinquish
any parts of the Deepwater Tano license at
some point, including any of the discoveries?
Hughes: The Deepwater Tano Petroleum Agreement was signed in March 2006.
Expiry of the TEN development and production area is in 2Q 2036, although we will
have to relinquish some of the area around
the Tweneboa gas find two years after production. At the moment, we do not have the
opportunity to drill appraisal wells on this
area, but we will need to look at this with the
government. We will also look again at the
surrounding area and satellites and will take
into account ITLOS’ decision. •
Above: Seadrill’s semisubmersible West Leo has
drilled and completed the first-phase TEN wells.
Left: Subsea 7 installed the FPSO’s mooring
piles, which were manufactured in Ghana.