METHOD FOR DEVELOPMENT OF HIGH-VISCOSITY OIL DEPOSIT Russian patent published in 2016 - IPC E21B43/16 E21B7/04 

FIELD: oil and gas industry.

SUBSTANCE: invention can be used in development of deposits of high-viscosity oil with water-oil zones of small thickness. Method comprises selecting a section of a deposit, oil-saturated with dynamic viscosity more than 400 mPa·s, with water-oil zone, where thickness of oil part of formation is greater than 10 m, and water-bearing part is not greater than 5 m. Main vertical boreholes are drilled on deposit. Lateral horizontal boreholes - BGS are cut from one of said boreholes with controlled filters towards closest neighbouring vertical well. Length of BGS is 0.5-0.9 of distance between said vertical wells. Distance between horizontal boreholes in productive formation is set not less than 4 m vertically. Water-bearing part of formation is perforated in vertical borehole. Two pipe strings are lowered into well, one of which is packed below sidetracking of lower BGS. Mixture of water at temperature higher than 50 °C, nitrogen and solvent is pumped through said string. Extraction of pumped mixture is carried out in circulation mode through adjacent vertical well, in side of which are drilled BGS. Optimal ratio of components of mixture is determined by laboratory investigations of oil displacement on cores. Oil is recovered through BGS through a second string. Oil extraction is carried out by means of equipment for dual production.

EFFECT: increasing sweep efficiency and oil recovery of deposits of highly viscous oil.

1 cl, 1 ex, 1 dwg