Cavernous-fractured carbonate reservoir: problem of water-oil displacement ratio substantiation

The authors discuss a problem of displacement ratio estimation in cavernous-fractured carbonate reservoir in a laboratory waterflood simulation. Process of oil displacement with water was reproduced using a filtration setup providing P-T reservoir conditions and Toshiba Aquilion 16 medical CT-scanner integrated with it. Experimental studies were carried out on core plug cut out of whole cavernous-fractured carbonate core. In order to compare the results with the classical approach, experiments of carbonate reservoir physical modelling were carried out on standard-size samples cut out of the whole core tested in the first stage. Analysis of the data obtained showed the influence of “scale effect”. CT-scanning method and material balance method for calculation of all fluids released from the modelled reservoir were both used in estimation of oil saturation/displacement ratio determination