Numerical study of different forms of synergetic CO2 injection and storage as an Enhanced Oil Recovery method

Resumo

Carbon capture, utilization, and storage (CCUS) is already seen as essential for sustainable development.
In the oil & gas sector, injecting CO2 into the reservoir is also an important Enhanced Oil Recovery (EOR) method,
producing effects on oil properties. Continuous injection, the CO2 use in Alternating Water and Gas (WAG) and
carbonated water injection, for example, can contribute to further oil recovery. This study aims to compare the
recovery factor (RF) and the geologic storage for different CO2-EOR techniques through numerical simulation.
For this, a reservoir model and a compositional fluid model were implemented in a commercial software. Then,
different injection settings were compared. As a benchmark, the injection flows were selected to maintain a similar
average Bottom Hole Pressure (BHP). As results, all CO2-EOR methods were better than water injection, with an
emphasis on continuous CO2 injection, with increases of more than 33% in the RF. The selection between
CO2-WAG cycles showed differences of more than 4.5% in the final RF. The tertiary CO2 injection, after water
injection, had the highest geological carbon storage efficiency, of 23%. With the results, it is expected to contribute
to the analysis of the CCUS potential and in optimizing the use of CO2-EOR.