METHOD FOR DEVELOPING AN OIL POOL WITH A CLAYEY RESERVOIR Russian patent published in 2018 - IPC E21B43/20 E21B43/17 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry and can be used for developing an oil pool with a clayey reservoir in order to enhance the oil recovery of formations by waterflooding. Method for developing an oil pool with a clayey reservoir comprises pumping working fluid through injection wells and extracting formation fluids through vertical and horizontal production wells. According to the first embodiment, mineralized water is pumped through the injection wells to the formation until the water cut of the production fluid up to 50 % (inclusive) is reached, after which three modes of developing an oil pool with a clayey reservoir are alternately used. First mode comprises pumping fresh water in the volume up to 0.5 (inclusive) of the pore volumes of the hydrodynamically coupled channels of the pay formation through the injection walls or until a bottom hole pressure value reaches 95 % of formation hydraulic fracturing. Second mode comprises processing the productive interval of the formation of the horizontal production well with a physical action – a device for generating elastic resonant pulses in the hydrosphere of the horizontal well and for maintaining during a technological pause for redistribution of filtration streams for 12–24 hours. Third mode comprises pumping mineralized water through injection wells until the average water cut of the production fluid is increased by 10 %. According to the second embodiment, the first and second development modes are such as in the first embodiment, and the third mode comprises pumping mineralized water or mineralized water containing 0.05 wt% of a non-ionic surfactant through injection wells until to the average water cut of the production fluid is increased by 10 %.

EFFECT: increasing the formation coverage and oil displacement, as well as improving reservoir properties of the pay formation of deposits with hard-to-recover hydrocarbon reserves.

1 cl, 1 dwg