Physical grounds of hydrocarbons recovery from a productive reservoir containing oil of different properties
The article describes physical grounds of multiphase filtration in hydrophobic carbonate reservoir saturated with oil of different properties. Core experiments revealed significant differences in filtering parameters. Reservoir development is described by abnormal displacement characteristic: when the level of reserves extraction is 65 % the water-flooding makes 19 %. Due to asphaltenes precipitation a hydrodynamic screen, preventing vertical movement of the underlying water, is formed. It leads to the reservoir pressure reduction that affects the rheological properties of oil and the reservoir characteristics. Field experiments of wells operation change identified the cycles various in time and technological effect, when, after an insignificant increase of the liquid production rate, there occurs almost synchronized decrease of the product water-flooding. Liquid flow-rates reduction led either to stabilization or even increase of water-flooding. Liquid flow-rates in field experiments did not exceed 75 % of the maximum values. The identified specific features should be used to regulate the reservoir development process.