1 research outputs found
Severe slugging with multiphase fluid transport and phase separation in subsea pipelines
Flow assurance and separation of multiphase oil and gas flows are becoming more
challenging as offshore development advances into more difficult environments. Petroleum
fluids are required to be transported to processing facilities over long distances and through
difficult terrain, as well as under varying temperatures and pressures. Severe slugging is a
well-known flow assurance problem that limits effective offshore petroleum production.
Gas-lifting and topside choking have been used for decades to mitigate this flow problem
in fluid transport and processing. However, the application of these techniques has been
challenged by design, cost, and footprint constraints. The introduced complexities require
detailed understanding of the detailed dynamics of fluid flow in highly compact designs.
Systematic experimental and modeling investigations of severe slugging in pipeline-riser
systems can provide useful information on these slugging mechanisms and characteristics.
Experimental studies are conducted in this thesis to determine the mechanisms and key
parameters involved in the slugging performance in fluid processing installations. Through
well designed experimental tests, the impacts of actuators on slugging are examined. This
thesis also focuses on control systems to suppress slugging in the pipeline-riser system
using experimental analysis and control models. The research also presents new models
that predict phenomena of slugging behaviour, and more importantly, fitting for control
designs in offshore flow separation.
Furthermore, this thesis identifies and quantifies the process variables and conditions
associated with both slugging and non-slugging regions, leading to the development of
more effective solution methods and correlations. Relevant correlations (including slugging frequency, production rates, gas injection rate, compression requirements, and
operating pressures) are developed by dimensional analysis techniques. The study develops
new models, data and useful information for better understanding of slugging in pipeline
systems. Sensitivity analyses to assist in the selection and design of more accurate control
methods are also presented. The research outcomes provide improved and more robust
models and guidelines for implementing slugging mitigation measures