So the real technical challenges that we’ve got are a significant water depth up to 2,000 metres,
we’ve got a low-pressure reservoir, and those two coupled together mean
that we’ve got to have a subsea separation; we’ve got to have artificial lift
to have that artificial lift we’ve got to have the big manifolds and mobo-casement ESPs subsea.
To power those ESPs we need large and high-power umbilicals,
and because of the water depth we need to have different design ...new design risers
to be able to cope with a water depth of this magnitude.
So subsea separation is a new technology for Shell.
The reason that we need it is because that we don’t have enough energy in the reservoirs
to lift the oil all the way up to the surface to the FPSO.
It’s a challenge because electrical submersible pumps are not able to pump oil
and gas and water all at the same time - they’re only able to pump liquids - oil and water.
And so the challenge and why we need separators is we need to separate the gas from the liquids
so that the gas can rise on its own then we can pump the liquids.
And so the real challenge is going to be making sure that these separators work efficiently,
that we’re not allowing gas to slip around into the pumps
because we will have very expensive pump failures if we start trying to pump gas in with our liquids.
And so the benefits of future projects by learning to do the subsea separation
is going to be big for Shell in Brazil and other places where we have heavy oil reservoirs.
On BC-10 with the Espírito Santo we’ve got the world’s first turret moored deep water FPSO
using steel "lazy wave" catenary risers.
Now in simple terms instead of having a normal catenary riser from the FPSO to the seabed
we’ve put in a lazy wave and that decouples the vessel movement from the touchdown point on the seabed
and that reduces the fatigue and stresses on the system.
For the subsea infrastructure to operate properly we need to run umbilicals
and what they are is tubes that go down to the valves and to the manifolds
and to the wells and primarily they provide a chemical support so we can pump inhibitors
and demulsifiers and things like that that we need to enhance the flow assurance.
We also would be able to transmit pressure to be able to operate the valves,
and we also have temperature and pressure sensors
that we need to be able to conduct electricity through these tubes.
For the high power ESPs, Electrical Submersible Pumps,
those big 1,500 horse-power pumps need an enormous amount of voltage to be able to operate.
If we didn’t develop this umbilical cross-section which combines all of them
we would have had to run multiple umbilicals which is very very costly,
there’s a limited number of slots that we can pull the umbilicals into the FPSO with,
so what we wanted to do is put them all together into one cross-section
it’s never been done before.
The three big technologies which have been the subsea separation and artificial lift being one,
with the steel lazy wave catenary risers being two,
and the electro-hydraulic umbilicals – developing those
and those being a success on BC-10 will allow us to look forward
to other deep-water projects in Brazil and elsewhere.