METHOD OF DEVELOPMENT OF MULTIHORIZONT OIL POOL Russian patent published in 2003 - IPC

FIELD: oil producing industry: applicable in development of multihorizon oil pools. SUBSTANCE: method includes oil withdrawal from formations through producing wells. Working agent is injected into formations through injection wells. Additional producing well is drilled down to upper producing formation and its productivity is analyzed. In case of insufficient productivity of tapped formation, additional producing well is drilled in interval between upper and lower producing formations. Additional producing well is cased in interval of absence of oil-bearing interlayers. Tubing string is lowered to drilled bottomhole. Formation fluids are withdrawn through tubing string from all uncased interval. Water-oil boundary in annulus is determined and tubing shoe is installed at level of water-oil boundary. After oil withdrawal from uncased interval, additional producing well is drilled to lower producing formation and oil is withdrawn. EFFECT: increased oil recovery from pool. 2 cl