Net-zero emission (NZE) production​

Substantial hydrocarbon reserves are located in tight reservoirs on the Norwegian Continen-tal Shelf (NCS). These reservoirs are challenging to produce primarily due to pore heteroge-neity, low permeability, and deep locations. Stimulation of the near well region can increase the productivity in such reservoirs. Several stimulation methods can be employed but their suitability to NCS need to be evaluated. Tight reservoirs require an optimal drainage strat-egy. Gas/Waterflooding can be used for pressure maintenance, and spontaneous imbibition of water into the oil-containing matrix can be important for successful oil mobilization and recovery optimization. Can optimized injection water also be used for improved stimulation?

Several large-scale CCUS projects are already planned or are under way where CO₂ is transported by pipeline to offshore reservoirs for long-term CO₂ storage and/or enhanced oil recovery (EOR). However, the high mobility of CO₂, unstable displacement front and reservoir heterogeneity strongly limits the CO₂ displacement and storage potential due to poor reservoir sweep efficiency. Viscous fingering, gravity override and flow in high permeability layers further reduce the volumetric sweep and the effectiveness of CO₂ injection processes. Thus, high CO₂ mobility and reservoir heterogeneity are major challenges for efficient CO₂ EOR and storage. Foam is a laboratory verified and field-tested method to mitigate high CO₂ mobility in subsurface reservoirs.

CO₂ storage in subsurface reservoirs is a solution for reducing anthropogenic CO₂ emissions. This potential will give rise to combined CO₂ EOR and CO₂ storage efforts. However, the high mobility of CO₂, unstable displacement front and reservoir heterogeneity strongly limits the CO₂ displacement storage potential due to poor reservoir sweep efficiency. The displacement efficiency can be improved by the application of CO₂ foam or carbonated water (CW).

The purpose of this project is to develop tracers to increase the knowledge about the flooded volume of the reservoir and thereby generating data to maximise the value creation on the NCS. Tracers and tracer methods for investigation and evaluation of important parameters as remaining oil saturation, relative permeability and wettability will be the focus for the devel-opment. The goal is to have a tracer method that can determine several of the parameters in-situ from the same tracer test by co-injection of tracers with different properties in the near well region. The main focus in 2022-2023 will be on tracers for wettability.

More and more hydrocarbon reservoirs are producing at high water cut. With the increasing cost of electricity and with the forthcoming CO₂ production limitations, reservoir energy must be utilized optimally. Hereby, we will analyse historical reservoir production data at the NCS to develop an energy consumption model. The model will be benchmarked against historical CO₂ emission data from the NCS allowing for optimization of the energy consumption from oil and gas fields both locally (field by field) and regionally (groups of fields). Data driven analyses will be complemented by physics-based reservoir modelling, with machine learning approaches to extract correlations from data first, and causal analysis after to extract causation.