DEVELOPMENT OF THICK OIL OR BITUMEN DEPOSITS Russian patent published in 2014 - IPC E21B43/24 

FIELD: oil-and-gas industry.

SUBSTANCE: proposed method comprises construction of pairs of horizontal production wells and injection wells arranged one above the other, and vertical observation wells. Heat carrier is injected via injection wells with heating of productive bed and creation of steam chamber. Product is extracted by steam-gravity drainage via production wells, steam chamber conditions being monitored. Note here that thick oil deposit is worked with adjustment of current size of steam chamber by changing of heat carrier injection volume and extraction of fluid from production wells. Observation wells are exposed below the lowest production horizontal well by at least 0.5 m but above the level of water-oil contact by 0.5-1 m. Additionally, well is drilled between adjacent pairs of horizontal wells. In case the area of steam chamber extension of productive bed is smaller than distance between pairs of production and injection wells, extra horizontal well is drilled. in case it is larger, vertical well is drilled. Note here that extra wells are exposed below the lower horizontal production well by at least 0.5 m but not lower than water-oil contact by over 0.5 m. Extra wells are heated by heat carrier to create thermal hydrodynamic communication with adjacent horizontal wells for symmetric and uniform extension of steam chamber around pairs of horizontal wells. Superheated steam or steam with hydrocarbon solvent or steam with inert gas is used as heat carrier.

EFFECT: higher yield, lower costs of bed heating.

3 dwg