The document outlines various challenges faced in subsea technology, particularly related to installation, maintenance, separation of oil/gas/water and sand, produced water disposal, remote monitoring, long-distance power transmission, local power generation, and the need for new materials suitable for extreme conditions. As depths increase, new and innovative solutions are sought to address these technical difficulties effectively and cost-efficiently. Input and ideas from readers are encouraged to tackle these challenges in subsea operations.

1. Subsea technology questions

2. The challenge:
Installation and maintenance
At 300 meters depth, we have it covered. But at depths up to 3000
meters, the physical conditions demand a radical re-think around
techniques and technology.

3. The challenge:
Installation and maintenance
Lowering a subsea production template to a depth of a few hundred
meters, using cables is a relatively straightforward process. But as the
depth increases, the dynamics change. There comes a point where the
weight of the cable played out exceeds that of the template itself — and it
keeps on increasing, placing enormous stresses on the surface vessel. Is
there an alternative method of installing subsea equipment?
Increased depths present additional challenges for the maintenance of
pipelines and equipment. Would it be possible to employ autonomous
remotely operated vehicles which remain on the seabed and are capable of
operating without the need for an umbilical?
These are just a few of the challenges we face. Any good ideas you might have on
subsea installation and maintenance are welcome.
Take the challenge!

4. The challenge:
Separation of oil/gas/water and sand !
We've pioneered robust solutions for separating produced oil and
gas from water and sand on the seabed down to 300 meters. But
greater depths require more resilient, compact and cost-effective
solutions.

5. The challenge:
Separation of oil/gas/water and sand !
We have successfully developed separation facilities which remove the need
to take the produced mixture of oil, gas and water to the surface, and
significantly increase recovery. It works well, but in deeper waters, the
design of the structure simply would not work. There may be other
methods of separation – for example involving centrifugal forces – but how
could these be made to work reliably at depths up to 3000 meters?
We face many challenges. Answers to these, or any other good ideas related to
the separation of oil, gas, water and sand are welcome.
Take the challenge!

6. The challenge:
Produced water disposal
Water separated from the well-stream can be re-injected. But as the
depth increases so do the physical challenges, as well as the costs.
Is there an alternative to re-injection?

7. The challenge:
Produced water disposal
The produced mixture from the wellstream can typically comprise of up to
90% water. In the course of extraction, this means dealing with significant
quantities of water. On a platform, water can be treated so that it can be
disposed of at sea, or alternatively produced water can be re-injected into
the well. At greater depths the cost of bringing the produced water up to
the platform with the wellstream increases and the costs involved in drilling
a well for re-injection become prohibitive. Is there a better, more cost-
effective way of handling water at these depths?
Your answer to this, or any other good ideas you might have related to produced
water disposal are welcome.
Take the challenge!

8. The challenge:
Remote monitoring and control
In our industry, knowledge is power. But placing monitoring and
control systems further from command centers brings out a range
of new challenges over reliability and accuracy.

9. The challenge:
Remote monitoring and control
Temperatures. Flowrates through pipelines. Precise quantities of oil and gas
in the wellstream. These variables, as well as many others, require constant,
accurate monitoring. And yet, at the extremes of the subsea environment,
conventional means of measurement may not always be the most durable.
But what are the alternatives?
The control systems we employ have typically been connected using copper
cable. These are gradually being replaced by fibre optics as a more effective
means of transmission. But there may be other solutions, and the question
of how to power these systems over increasing distances remains.
Do you have any answers to the above, or any other good ideas related to remote
monitoring and control? Please let us know.
Take the challenge!

10. The challenge:
Long distance power transmission
Photo © Expro Connectors & Measurements
As tie-backs to infrastructure increase in length, how is it possible
to maintain a consistent, reliable power supply to installations on
the seabed?

11. The challenge:
Long distance power transmission
Over longer distances, the principal challenge is how to maintain a stable
power supply to the remote production facilities, which in some cases can
be more than 100 km from land.
In addition, to install electrical equipment such as compressors, pumps and
the necessary electrical controls and switchgear at even greater water
depths is to place them in a particularly hostile environment. One solution
has been simply to encase equipment in a pressure chamber. However,
particular challenges remain – not least how to maintain the integrity of the
chamber, and the electrical connections, especially where power cables
penetrate the chamber walls. What are the solutions that will allow electrical
equipment to keep on working at increased depths?
Your answer to this, or any other good ideas you might have regarding long
distance subsea power transmission are welcome.
Take the challenge!

12. The challenge:
Local power generation and storage
It may be possible to power smaller installations and control
systems using localized sources. But what form could these power
sources take?

13. The challenge:
Local power generation and storage
To avoid the problems presented by the increasing length of power feeds,
one solution would be to use power generated locally to run equipment on
the sea bed. Known means of generating power could include water
turbines, or windmills on the sea surface. But what are the alternatives?
Also, what is the best way to store energy from these power sources? Are
there batteries that could be used at increased depths? Or systems for
storing energy using a flywheel?
We are open to any ideas related to local power generation and subsea storage.
Take the challenge!

14. The challenge:
New materials
Working at extremes of pressure and temperature, subjected to
corrosive and abrasive forces, traditional materials rapidly reach
the limits of performance. But what are the materials that can
replace them?

15. The challenge:
New materials
The environments we work in and the operating conditions we're forced to
deal with place equipment and materials under extreme pressure. Sand
content in the wellstream flowing through pipelines under pressure is
highly abrasive. Sea water and the fluids extracted from subsea wells are
inherently corrosive. Wax and hydrates can form and adhere to pipelines at
low temperatures, causing blockages. In each of these scenarios, and
others, the choice of materials we use could provide a more effective and
durable solution.
But which materials? All good ideas are welcome.
Take the challenge!

16. Thank you.
Subsea technology questions
Sigrun Daireaux
Business Developer
idea@statoil.com
innovate.statoil.com