Stabilizing Slug Control Using Subsea Choke Valve
This thesis study the possibility of riser slugging control in oshore oil production
using a subsea choke valve. A 5-state simplied model of a well-pipelineriser
system is introduced and tted to a reference model in the ow simulator
OLGA. The models have two inputs, a subsea valve at the wellhead and a topside
valve at the top of the riser. The eect the valves have on the behavior of
the simplied model are tted to simulation data from the OLGA-model using
An input-output controllability analysis of the simplied model show that
anti-slug control using a subsea valve at the wellhead is more dicult than the
conventional solution, which is to use the topside choke valve. This is conrmed
by simulations on the simplied model using Hinfinity-controllers.
Stabilizing control of the OLGA-model using the subsea valve was unsuccessful,
despite testing dierent measurement combinations and control structures.
A more promising solution for controlling riser slugging using a subsea valve is
tested in OLGA, where a subsea valve located near the base of the riser can keep
the system stable at riser slugging conditions. This is also seen in an experiment
on a small scale ow lab.
Place, publisher, year, edition, pages
Institutt for teknisk kybernetikk , 2012. , 76 p.
ntnudaim:7131, MTTK teknisk kybernetikk, Ny energi, olje og gass
IdentifiersURN: urn:nbn:no:ntnu:diva-18525Local ID: ntnudaim:7131OAI: oai:DiVA.org:ntnu-18525DiVA: diva2:566010
Hovd, Morten, ProfessorSkogestad, SigurdJahanshahi, Esmaeil