ChemFlow - Enabling subsea tiebacks with complex fluid chemistry

IPN ChemFlow - Enabling subsea tiebacks with complex fluid chemistry. To minimize the environmental footprint and reduce the costs of the petroleum production, many future field developments are likely to be tiebacks, where new assets are connected to existing transport infrastructure instead of installing new infrastructure. In many areas, tiebacks are the only option to develop offshore fields cost efficiently. Tieback solutions do however typically require longer pipelines and consequently require more accurate flow predictions because the prevailing prediction errors are proportional to the pipeline length. Most petroleum production systems deliver fluids with complex physical chemistry, where the complexity arises either from chemical compounds naturally occurring in the production flow or chemicals added to prevent corrosion or other flow assurance issues. The presence of chemicals can change the flow behaviour drastically, potentially causing severe problems such as flow instabilities, poor separation, foaming, and thus production loss. The industry is not equipped to predict problems associated with chemicals and surfactants, as current models can only deal with "ideal" fluids in the pipelines. This is especially important in tiebacks with long pipelines, where chemical injection may be increased to compensate for the dilution caused by connecting pipelines. The consequence is that decisions regarding design and operation of petroleum production systems are based on incomplete information and are suboptimal from both an economic and environmental viewpoint. To improve this, ChemFlow aims to develop simple, robust characterization methods for complex fluid systems. ChemFlow will also develop new models in the multiphase flow simulator LedaFlow, enabling the industry to predict the behaviour of complex fluid systems. By conducting multiphase pipe flow experiments, accuracy of the new prediction models can be validated. It is believed that the planned innovations will be important for profitable development of petroleum production systems with reduced CO2 footprint and minimum use of chemicals. By improving the accuracy of these predictions, ChemFlow contributes to enabling tieback solutions that can play a key role for Norway's ability to meet emission targets while maintaining a competitive industry. Furthermore, export of the technology can have a significant impact on the environmental footprint from global oil and gas industry. During the first year of ChemFlow several milestones have been achieved: * New functionality advancing the simulation of three-phase vertical flow as well as slug flow is implemented and made commercially available in the 2.7 release of LedaFlow including Slug Capturing 2. * Modelling of surfactant- stabilized gas/liquid systems has started using both experimental data previously generated in the multiphase laboratory and field data provided by our partners. Preliminary results have indicated that separated oil/water flow (i.e. a free water layer) can trigger unstable flow. * The experiments planned for 2021 is close to completion. The first campaigns focused on liquid dominated oil/water flows and gas/oil/water flows with/without crude oil spiking. A large amount of relevant data is generated and will be basis for thorough analysis and modelling the coming months. Before the end of 2021 an additional experimental campaign on stratified/slug transition will be conducted to investigate how surface tension affects the onset of waves and slugs. * The work on fluid characterisation has started with focus on gas/liquid systems. Both foaming and interfacial rheology are investigated. The innovation project ChemFlow is owned by LedaFlow Technologies DA and project partners are SINTEF, Kongsberg Digital, TOTAL E&P, ConocoPhillips og Lundin. The project benefits from collaboration with partner representatives in USA and France in addition to contributions from the Norwegian entities.

To minimize the environmental footprint and reduce the costs of the petroleum production, many future field developments are likely to be tiebacks to permanent installations. In many areas, tiebacks are the only option to develop offshore fields cost efficiently. Most petroleum production systems deliver fluids with complex physical chemistry, where the complexity arises either from natural surfactants or chemicals added to prevent corrosion or other flow assurance issues. The presence of chemicals/surfactants can change the flow behaviour drastically, potentially causing severe problems such as flow instabilities, poor separation, foaming, and thus production loss. The industry is not equipped to predict problems associated with chemicals and surfactants, as current models can only deal with "ideal" fluid systems. The consequence is that decisions regarding design and operation of petroleum production systems are based on incomplete information and are suboptimal from both an economic and environmental viewpoint. To improve this, ChemFlow aims to develop simple, robust characterization methods for complex fluid systems. ChemFlow will also develop new models in the multiphase flow simulator LedaFlow, enabling the industry to predict the behaviour of complex fluid systems. By conducting multiphase pipeline flow experiments, accuracy of the new prediction models can be validated. It is believed that the planned innovations will be important for profitable development of petroleum production systems with reduced CO2 footprint and minimum use of chemicals. ChemFlow contributes to tieback solutions that can play a key role for Norway's ability to meet emission targets while maintaining a competitive industry. Furthermore, export of the technology can have a significant impact on the environmental footprint from global oil and gas industry.