This thesis study the possibility of riser slugging control in oshore oil productionusing a subsea choke valve. A 5-state simplied model of a well-pipelinerisersystem is introduced and tted to a reference model in the ow simulatorOLGA. The models have two inputs, a subsea valve at the wellhead and a topsidevalve at the top of the riser. The eect the valves have on the behavior ofthe simplied model are tted to simulation data from the OLGA-model usingbifurcation diagrams.An input-output controllability analysis of the simplied model show thatanti-slug control using a subsea valve at the wellhead is more dicult than theconventional solution, which is to use the topside choke valve. This is conrmedby 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 istested in OLGA, where a subsea valve located near the base of the riser can keepthe system stable at riser slugging conditions. This is also seen in an experimenton a small scale ow lab.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:ntnu-18525 |
| Date | January 2012 |
| Creators | Lieungh, Mats |
| Publisher | Norges teknisk-naturvitenskapelige universitet, Institutt for teknisk kybernetikk, Institutt for teknisk kybernetikk |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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