It nitrogen injection has been proven as a competitivealternative for volatile oil reservoirs lately found inPiedemonte area of Colombia, taking into account thereservoir fluid nature and the reservoir conditions. Alaboratory study was carried out by the authors in theEnhanced Oil Recovery Laboratory of Colombian PetroleumInstitute.Three corefloods were carried out using Berea sandstoneand volatile oil samples from the Piedemonte area andnitrogen as displacing agent. One of these corefloods wasconducted in a long Coreflooding apparatus, and the otherones, in a short Coreflooding apparatus connected with a slimtube in a order to achieve miscibility conditions. The mainvariable studied was the flow rate, which represents threedifferent flow regimes. The scaling criteria taken was adimensionless group, which relates viscous and gravity forces,called gravity number.Displacement efficiencies determined were around 50%,65% and 80% for each one the tests. The results of thesecorefloods were compared to determine the best scheme ofnitrogen injection. Results have successfully confirmed theeffectiveness of nitrogen as displacing agent for this kind ofoils and the better swept efficiency given by the equilibriumbetween the governing forces.
展开▼
