OIL RECOVERY SYSTEM AND METHOD Russian patent published in 2018 - IPC E21B43/24 E21B43/22 C09K8/592 

FIELD: oil and gas industry.

SUBSTANCE: group of inventions relates to recovering oil from a formation. Oil recovery method comprises: providing an oil recovery formulation that comprises at least 15 mol% dimethyl sulphide (DMS), wherein said oil recovery formulation is first contact miscible with liquid phase petroleum; providing steam or hot water having a temperature of at least 85 °C; introducing the steam or hot water and the oil recovery formulation together into a subterranean oil-bearing formation comprising crude oil, having a dynamic viscosity of at least 1,000 mPa⋅s (1,000 cP) at 25 °C and an API gravity at 15.5 °C (60 °F) of at most 20 °C as measured in accordance with ASTM Method D6822, wherein the oil recovery formulation comprises at least 15 wt% of the combined steam or hot water and oil recovery formulation introduced together into the formation; contacting the steam or hot water and the oil recovery formulation with the oil in the formation; and recovering oil from the formation after introducing the steam or hot water and the oil recovery formulation into the formation.

EFFECT: producing about 60 % of the oil remaining in the core after waterflooding.

16 cl, 11 dwg, 8 tbl, 3 ex