METHOD FOR OIL PRODUCTION AT THE LATER STAGE OF OIL DEPOSIT HAVING WATER BED DEVELOPMENT Russian patent published in 2007 - IPC E21B43/16 

FIELD: oil production, particularly to develop oil deposits having underlaying water beds in the case of baffle absence between oil-saturated and water-saturated zones.

SUBSTANCE: method involves perforating roof oil-saturated and bottom water-saturated reservoir zones to extract water from water-saturated zone and to produce oil from oil-saturated zone thereof, wherein water-saturated zone perforation is carried out with lesser perforation orifice density in comparison with that in oil-saturated zone. Water-saturated zone and oil-saturated zone perforation density ratio is determined by mathematical modeling on the base of geological production data of above deposit with water-saturated zone perforation density providing pressure relief thereof and facilitating current reservoir pressure maintenance at oil-saturated zone pressure level. To provide above pressure maintenance oil and water viscosity under reservoir conditions, initial reservoir pressure and filtering parameters in reservoir zones, namely oil-saturated zone thickness, absolute permeability, relative permeability, porosity and oil saturation, are determined. Then productivity in filtering block, which models bottomhole formation zone, is changed and perforation orifice density corresponding to the highest producible oil index is determined.

EFFECT: increased efficiency of oil deposit development due to prevention of bottom water coning.

1 ex, 2 tbl, 6 dwg