DEVELOPMENT METHOD OF MULTILAYER NON-HOMOGENEOUS OIL DEPOSIT Russian patent published in 2015 - IPC E21B43/14 E21B43/16 

FIELD: oil and gas industry.

SUBSTANCE: invention is referred to development of oil deposits represented by multilayer reservoirs and non-reservoirs non-homogeneous in their injectivity. The method consists in construction of multihole injection well system made as horizontal borehole drilled in stable rocks at preset distance from roof of underlying oil source rocks and a number of downward offshoots drilled out of it and multihole producing well system made as horizontal borehole drilled in stable rocks at preset distance from foot of unstable overlying oil source rocks prone to collapsing and key-seating and a number of upward offshoots drilled out of it. At that upward offshoots of the multihole producing well system are drilled in parallel between downward offshoots of the multihole injection well system. Then offshoots in the multihole injection well system and multihole producing well system are perforated in the same plane in intervals corresponding to location of non-reservoir layers with further hydraulic fracturing from offshoots and injecting of proppant through the multihole injection well system. Thereafter through the multihole injection well system oxygen-containing mixture is injected to non-reservoir layers thus creating oxidising area with increased temperature and oil is produced through the multihole producing well system from non-reservoir layers. At that upward offshoots of the multihole producing well system and downward offshoots of the multihole injection well system are placed at distance from each other that is not less than radius of the zone of complete oxygen intake at injection of oxygen-containing mixture.

EFFECT: improved production rate of the deposit.

1 dwg