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Annual Report 2015
Most processes in the oil and gas industry,
whether subsea or topside, are in need of some
sort of control. Many variables like liquid level,
pressure and flow rate are influencing the quality
of the product and the operators need to be able
to manipulate these variables. While some of
this manipulation can be performed manually,
some require, or can be significantly improved by,
automatic control. Operators can choose a set point
for operation and the control system ensures that
the variable converges to, or at least stays close to,
this set point, including taking into account safety
margins and hardware constraints. Design of the
automatic control systems is challenging, both
scientifically and practically, due to the complex
behaviour frequently seen in subsea processes.
Designing these advanced automatic control
algorithms is the goal of this subproject.
In this subproject, we will investigate control
of several hydrocyclone separators in series to
improve the quality of produced water, dampen
slugs in risers to prevent overloading topside
equipment, control compact flotation units for
separation of oil and water, and other related
Control of subsea processes
Project manager and
main PhD supervisor,
Associate Prof. Christian
Holden
PhD candidate,
Sveinung Johan Ohrem
Co-supervisor,
Prof. Olav Egeland
topics. The research topics are chosen based
on suggestions from our industry partners. A
traditional control system would need continuous,
expensive and time-consuming re-tuning by
specially trained personnel to cope with the
complexities and uncertain behaviour. Control
may even be impossible. The advanced control
algorithms we will design as a part of this project
will be able to handle the complexities and uncer-
tainties in a truly autonomous manner and obviate
the need for re-tuning. We believe advanced
control methods, like non-linear and adaptive
control, provide the most suited approach for
subsea processes.
To validate the developed methods and improve
the quality of research, we are building a small-
scale separation laboratory that will include
hydrocyclones, bulk separation, coalescing pumps
and other compact separation systems. Our
industry partners are very interested in improv-
ing the control algorithms used in a hydrocyclone
separation system. Phase 1 of the laboratory,
which is planned for construction in 2016, will pre-
dominately focus on hydrocyclones.
Figure 16. Compact separation
laboratory, phase 1.
Co-Supervisor,
Prof. Sigurd Skogestad