Enhanced Oil Recovery methods - Moving Science into Applications

We have developed a first EOR network simulation model and applied the model to our novel polymer and LPS design processes. Mechanistic models have been developed to investigate viscoelastic and shear thickening effects on microscopic displacement. WAG processes have been connected through mechanistic modelling both for miscible and immiscible WAG processes. Pore scale to core scale issues has been studied. Representative elementary volume has been estimated for heterogeneous carbonate rock material. Mechanistic modelling of several EOR processes has been studied on Darcy scale models and has been compared to experimental results. We have identified efficient new hybrid EOR processes. High oil recovery have been shown both for low salinity in combination with surfactant and polymer. Documentation of CO2 foam efficiency compared to hydrocarbon foam has been studies, showing weaker CO2 foam than HC foam. Polymer flow at adverse mobility ratio has been studies and a high potential for polymer has been proved. Core to field predictions has been addressed during the project, but has been expensive studied in other projects with oil companies. We have also started an ongoing EOR upscaling JIP project supported by 7 oil companies. Professor Skauge has been awarded a Foundation CMG (Computer Modelling Group) chair in EOR. The cooperation with CMG has led to implementation of WAG hysteresis in GEM and developed options for applications of complex hybrid EOR in conventional simulation tools. The current ongoing JIP on upscaling of EOR processes benefit from the development and have set the scene for technology implementation and training in oil companies.

Focused projects on EOR methods are necessary in order to achieve the high ambitions for reserve replacement and recovery factors that have been set for the NCS fields. The regained interest in these methods has generated an increasing demand to design an d implement EOR measures for specific oil fields. Investigating the potential for EOR by improved microscopic displacement efficiency requires that the basic mechanisms governing the processes are well understood, and can be included into predictive model ling tools. At present, this is not the case for many EOR methods. Most of the Norwegian fields are developed with water flooding, and are therefore possible candidates for implementing water additives to enhance the recovery. This fact is also reflected in the balance of the proposed research project, where waterflood improvement is the dominant part. However, the focus on moving CO2 injection forward towards application is also an important national concern, and we think our approach could be a step i n this direction. The main tasks are directed against new and better methods for improving microscopic displacement. The application of EOR processes is prevented by among other the lack of possibilities to predict the gain for a specific oil reservoirs . This project focuses on describing the mechanisms involved and to upscale the EOR effect to the field scale. Cost and logistic challenges has also limited the use of EOR in the North Sea. Therefore, the project introduces several new concepts that coul d move the pilot and field implementation forward. For an oil field on decline, the chase for quick solutions to increase oil recovery will always be the driving force. This project, on the other hand, will ensure that the increased knowledge will be tr ansformed into scientific results that can be made available and will be directly practically applicable for later oil field projects