RECOVERY METHOD OF LAYERED HETEROGENETIC OIL RESERVOIRS BY IMPULSE LOW-MINERALISED WATER FLOODING Russian patent published in 2017 - IPC E21B43/20 

FIELD: petroleum industry.

SUBSTANCE: invention refers to the petroleum industry and allows solving the problem of increasing of oil production from the layered heterogenetic oil reservoirs by the impulse pumping of low-mineralised water. The method includes the cyclical increasing and decreasing of pumping pressure of the operation agent in injection wells, application of low-mineralised water as the operation agent, and the extraction of products from production wells. Initially, the site with the dispersion of permeability of oil-saturated interlayers of at least 30% is selected. Low-mineralised water is used from the surface watercourses, rivers, lakes, seas; water is to be decontaminated and filtered before the pumping. The pumping of the agent start to conduct into the injection wells with gradual consumption increasing up to (0.7-0.8)·P_rock, then, the consumption is reduced down to the value, at which the pumping pressure is (0.1-0.2)·P_rock. Cycles of increasing/decreasing of the consumption of low-mineralised water will repeat many times. The rate of the daily consumption is set by 2-50 m³/day per one injection well. The bottom-hole pressure is kept at the same level in the close production wells.

EFFECT: proposed method allows increasing the oil recovery factor from the layered heterogenetic oil reservoirs by means of the application of the impulse pressurisation and pumping of low-mineralised water.