dc.description.abstract | Deep geologic injection of supercritical carbon dioxide (CO₂) for enhanced oil recovery (EOR), plays an important role in the sequestration of CO₂ to minimize the impact of CO₂-emissions due to global warming. CO₂-EOR refers to the oil recovery technique where supercritical CO₂ is injected to the reservoirs to stimulate oil production from depleted oilfields. The CO₂ mixes with the stranded oil, not producible by primary and secondary oil recovery techniques, changing the oil property and making the immobile oil mobile and producible.
The objective of this Master’s thesis was to study CO₂-injection into a carbonate reservoir. The study includes near-well simulations of oil production and CO₂-distribution, using the reservoir software Rocx in combination with OLGA.
CO₂-injection into a carbonate reservoir increases the oil recovery, but simultaneously the water production is increased.
Carbonate reservoirs with fractures have low oil production, high water production, early water breakthrough and high water cut.
Water breakthrough occurs after only 2.9 days in the fractured reservoir, and the water cut is 97.5 %. Closing the fractured zone causes delayed water breakthrough and dramatically reduced water cut, resulting in improved oil recovery as well as lower production and separation costs.
The simulations indicate that CO₂-injection into a carbonated reservoir in combination with closing fractured zone result in good distribution in the reservoir. | nb_NO |