METHOD FOR DEVELOPMENT OF ULTRAVISCOUS OIL DEPOSIT BY THERMAL METHODS AT A LATE STAGE Russian patent published in 2020 - IPC E21B43/24 E21B7/04 E21B49/00 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil-producing industry. Method for development of ultraviscous oil deposit by thermal methods at a late stage of development involves pumping of steam into upper injection wells, heating of productive formation with creation of steam chamber, extraction of oil through lower production wells, at the late stage of development, termination of steam injection, pumping of hot water into the formation and extraction of products, note here that steam injection to upper injection wells is stopped, while lower production wells are converted to injection of hot water at temperature of 40-65 ° C. Initially, after geophysical surveys through observation wells, the deposit is drilled in rows of parallel paired horizontal producers and injection wells, directed towards similar corresponding wells from adjacent row with holding distance between bottoms, excluding steam and / or hot water from one well into another. After transferring to the lower horizontal production wells hot water injection, geophysical survey is carried out in observation wells to determine oil-saturated zones of the formation, in which additional production horizontal wells are drilled in the overhead part of the productive formation between the faces of previously drilled horizontal wells at distance of 1-3 m from the roof of the productive formation.

EFFECT: high efficiency of heat action, maximum possible extraction of residual ultraviscous oil from the reservoir part of the productive formation, avoiding fast flooding of production additional wells at a late stage of development.

1 cl, 1 ex, 2 dwg