Imroved Glycol Loop Operation

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There is an increasing number of offshore gas fields where wet gas and condensate is transported in multiphase pipelines, unprocessed or partly processed, over long distances. Hydrate and corrosion control while preventing scale formation, are key issues in order to avoid serious upsets in the transport pipeline or the process system. The project addresses primarily fields where monoethylene glycol (MEG) is used as hydrate inhibitor. Effective use of MEG requires controlled solids and water removal. Othe rwise, salts from formation water, corrosion products and added chemicals may cause scaling, clogging and serious production upsets. The project is divided in two maintasks: Task 1: Earlier projects have generated a thermodynamic basis that makes it pos sible to predict precipitation risks and to some extent control precipitation. This includes a project run by the current project group where nucleation and growth models for calcium and iron carbonate were developed. The proposed project will take this f urther and develop models for other carbonates, ion interactions, growth on surfaces and seeding by foreign particles. The temperature and MEG range will also be enlarged and will include conditions for flash separation of water and MEG from salt saturate d highly concentrated MEG . Task 2: A simulator for MEG systems was developed in an earlier project. It is operational and is already a useful tool for process design and problem solving. It includes major process components and pipelines relevant for t he use and recycling of MEG. This project will improve the simulator by extensions within the following areas: Thermodynamics and kinetics (including more species, adding new kinetic models and allowing control loops), unit models (accounting for growth o n surfaces and enhanced treatment of solids), and validation of the thermodynamics, kinetics and global simulator behaviour.