MULTILAYER OIL DEPOSIT DEVELOPMENT METHOD Russian patent published in 2014 - IPC E21B43/14 E21B43/30 

FIELD: oil and gas industry.

SUBSTANCE: production zones are determined, producing and injection wells are drilled, oil recovery is made through producing wells and working fluid injection is made through injection wells. At that the four following zones are indentified as production zones: two terrigenous and two carbonate zones, at the end of the second stage of oil deposit development when maximum year oil production parameters start decreasing and measures are performed on year-by-year basis starting since the first year of the method implementation. During the first year two vertical producing wells and one injection well are drilled for the first zone, offshoot is made in the fourth zone from the existing piezometric well, one producing well is switched to water injection in the second zone and one piezometric well is switched to a producing well for the first zone. During the second year one well is switched to injection in the second zone, one well is equipped with installation for downhole pumping from one horizon to another within limits of the first zone, one hole is equipped with dual production unit for the first and second zones. During the third year one well is switched for injection in the first zone, one hole is equipped with dual pumping unit for the first and second zones, two holes are equipped with dual production unit: one from the first and second zones and one from the fourth and first zones; one horizontal offshoot is made at the first zone from the existing producing well, one piezometric well is started up as a producing one for the third zone. During the fourth year one vertical producing well is drilled for the fourth zone; during the fifth year one well from the third zone is witched for production at the fourth zone; during the eighth year one horizontal offshoot is made at the first zone from the existing producing well.

EFFECT: improving oil recovery rate of the deposit by optimisation of its development system.

2 cl, 7 dwg