ChemFlow - Enabling subsea tiebacks with complex fluid chemistry

IPN ChemFlow - Enabling subsea tiebacks with complex fluid chemistry. To minimize the environmental footprint and reduce 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 regions, tiebacks are the most cost-efficient solution for developing offshore fields, and leveraging existing infrastructure globally is crucial for energy companies striving to achieve NetZero. A tieback solution does 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 maybe 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 also develops 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 environmental footprint. 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. ChemFlow has reached several important milestones: During the first years of operation, experiments on fluid characterisation were conducted both on gas/liquid systems and on oil/water systems. The results serve as a basis for establishing guidelines for new characterisation methods for complex fluid systems. Furthermore, pipeline flow experiments have been conducted at SINTEF’s multiphase flow laboratory at Tiller. A large amount of relevant data was generated. It has been used for thorough analysis and several new models have been developed. Already in 2021 new functionality advancing the simulation of three-phase vertical flow as well as slug flow was made commercially available in the 2.7 release of LedaFlow. In 2024 an R&D release of LedaFlow was provided to the partners, including: 1) A new oil/water emulsion evolution model. This feature, when activated, allows the user to predict how emulsions evolve over long distances. 2) An improved oil/water dispersion model, enhancing the accuracy of the oil/water flow regime predictions. 3) An improved gas/oil- and oil/water shear stress models enabling more precise prediction of liquid- and water accumulation. 4) A model for gas entrainment in liquid films. The innovation project ChemFlow is cofounded by the Research Council of Norway and industry. It is owned by LedaFlow Technologies DA and project partners are SINTEF Industry, Kongsberg Digital, TotalEnergies, ConocoPhillips and AkerBP. 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.