METHOD OF SECONDARY DEVELOPMENT OF HIGH-VISCOSITY OIL DEPOSIT Russian patent published in 2003 - IPC

FIELD: secondary methods of development of high-viscosity oil deposits earlier operated by mining method under conditions of depletion drive. SUBSTANCE: method includes drilling of wells from surface with well bottoms located in region of underground wells drilled from underground gallery in primary development of deposit by mining method. Producing wells are drilled from surface on block boundaries. Producing well of increased diameter is drilled in block center bypassing the underground gallery. Injection wells are drilled within block. Then, after well completion by steam-cycling treatment, treatment with the help of solvents of bottom-hole zones of all wells, heat carrier is injected into injection wells. Fluid is withdrawn from producing wells. Heat carrier is injected at low rate to prevent break-through of heat carrier to underground mine workings with concurrent control over temperature of drilling gallery. With increase of said temperature by 5 C, cyclic injection of heat carrier is carried out with simultaneous redistribution of fluid withdrawal in central and boundary producing wells towards increase of withdrawal from the latter. EFFECT: higher coverage and oil recovery from formation, reduced unproductive losses of heat. 4 dwg, 1 ex