DEVELOPMENT METHOD OF HIGH-VISCOSITY OIL AND BITUMEN DEPOSIT Russian patent published in 2012 - IPC E21B43/24 

FIELD: oil and gas industry.

SUBSTANCE: development method of high-viscosity oil and bitumen deposit involves drilling and arrangement at least of two vertical wells with further secondary opening in them of upper and lower parts of productive formation, lowering to each well of tubing string with packer and separation of opening intervals with packer in production string, cyclic steam pumping to the formation through upper opening interval and extraction of formation fluid through lower opening interval. Between wells there drilled and arranged at equal distance is additional vertical well so that constant extraction of formation fluid from secondary opened lower part of productive formation and cutting of branch holes in upper part of productive formation is provided. Branch holes are made in inclined direction from roof to bottom of productive formation in the direction of peripheral wells with distance of inclined section, which is determined with linear size of its horizontal projection within the limits of 5-95% of the shortest distance to peripheral wells. In branch holes there separately provided is constant steam pumping to lower part of productive formation and steam pumping to upper part of productive formation when steam pumping to peripheral wells is stopped. At that, from peripheral wells via tubing string there performed is extraction of formation fluid in constant mode, and steam pumping to tube space of peripheral wells is stopped at water flooding of formation fluid to 95-97% and steam pumping is renewed when water flooding of formation fluid is decreased to 85%.

EFFECT: intensifying formation fluid inflow to wells at development of high-viscosity oil and bitumen deposit which is non-homogeneous as per the productive formation section, especially at its early stage.

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