METHOD OF EXTRACTING HIGH-VISCOSITY OIL AND NATURAL BITUMEN FROM A DEPOSIT Russian patent published in 2019 - IPC E21B43/24 E21B43/26 E21B43/22 C09K8/592 C09K8/524 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry. Method of extracting high-viscosity oil and natural bitumen from deposit involves pumping into wells of solvent consisting of viscosity of reducing solvent, which is aliphatic hydrocarbons with number of carbon atoms of 5–7, and an asphaltenes solvent, which is aromatic hydrocarbons, and subsequent extraction of the product. Prior to injection, preliminary investigations and determination of core oil composition are carried out, and composition of fringe and forcing composition is selected based on said composition. Composition of fringe is injected into well at pressure exceeding hydraulic fracturing pressure. Composition of fringe includes non-ionic surfactant, the volume ratio of aliphatic, aromatic and surfactant components is (90–80):(≤10):(≤10). Then well is conditioned for reaction. After holding for reaction, a mixture of aliphatic components with an ionic surfactant is used as a pushing composition to reduce interfacial tension between the injected composition and steam condensate to improve steam penetration. Then steam is pumped to reduce viscosity of extracted product.

EFFECT: reduction of steam supply time, more complete extraction of hydrocarbon components from productive formation, prevention of formation of a high-viscosity emulsion due to maintenance of asphaltenes in suspended state, increase of economic efficiency due to use of one well, reduction of environmental risks.

3 cl, 3 dwg