METHOD OF OPERATING A PAIR OF WELLS PRODUCING HIGH-VISCOSITY OIL Russian patent published in 2025 - IPC E21B43/24 E21B7/04 E21B47/00 

FIELD: mining.

SUBSTANCE: invention relates to oil industry. Method of operating a pair of wells producing high-viscosity oil includes the construction in the productive formation of a horizontal production well and an injection well located above, conducting geophysical studies in the horizontal shaft of the injection well to determine oil saturation along the horizontal shaft, placing two tubing strings in the injection well, wherein the end of the tubing string of a smaller diameter is placed at the beginning of the horizontal shaft, and the end of the tubing string of a larger diameter is placed at the end of the horizontal shaft. A geological model of the deposit is pre-built; a horizontal shaft of the injection well is placed at one absolute mark along the whole length of the well, and a horizontal shaft of the production well is arranged along an ascending trajectory. Vertical distance between horizontal shafts of production and injection wells at beginning of horizontal shafts was 7-9 m, and the distance between the production and injection wells horizontal shafts at the end of the horizontal shafts is calculated by the formula L_z=L_p⋅0.65, where L_z is distance between horizontal shafts of production and injection wells at end of shafts, L_p is the distance between the horizontal shafts of the producing and injection wells at the beginning of the shafts. Initial heating of injection and producing wells is performed by steam injection to tubing smaller of larger diameter of injection well and producing well in volume of 80 t/day for two months. Then wells are stopped for thermocapillary impregnation for 20 days. After that, steam pumping is resumed to tubing smaller of larger diameter of injection well with volume of 85-90 t/day, and production well is switched to extraction of liquid with flow rate of 80-120 t/day. When water cut exceeds 93 % the tubing smaller of larger diameter is displaced to the middle part of the injection well and steam is pumped to the tubing smaller of larger diameter and via the tubing smaller of smaller diameter of the injection well.

EFFECT: higher efficiency of production of high-viscosity oil due to creation of steam chamber stretched along horizontal shaft of wells and involvement in development of previously not captured zones of formation, uniform formation heating, increased overhaul period of pumping equipment due to maintenance of optimum temperature at the beginning of horizontal wells.

1 cl, 1 dwg, 1 ex