METHOD OF HIGH-VISCOSITY OIL DEVELOPMENT Russian patent published in 2013 - IPC E21B43/24 C09K8/592 

FIELD: oil and gas industry.

SUBSTANCE: in the method of development for high-viscosity oil deposit that includes stages of steam injection into injection well, productive stratum heating with creation of steam pocket, oil recovery through recovery well, pumping of produced water to injection well when project value of residual oil saturation is reached and steam injection is cancelled concentration of hydrocarbonate-ions is determined in produced water. Produced water with concentration of hydrocarbonate-ions of at least 3 g/l is subject to pumping into wells. When concentration of hydrocarbonate-is less than 3 g/l at temperature more than 100°C in a steam pocket carbamide is added into produced water. When temperature in the steam pocket drops below 100°C sodium, ammonium or potassium carbonate is added into produced water and these substances decompose with release of carbon dioxide gas under effect of heat accumulated in the steam pocket.

EFFECT: increase in efficiency of thermal-steam treatment during recovery of residual oil due to use of heat accumulated in the steam pocket when steam injection is terminated.

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