METHOD FOR INCREASING OIL RECOVERY OF BEDS OF TERRIGENOUS DEVONIAN DEPOSITS WITH DIFFERENT PERMEABILITY Russian patent published in 2024 - IPC E21B43/20 

FIELD: oil, gas and coke-chemical industry; mining.

SUBSTANCE: invention relates to a method for increasing oil recovery of formations of terrigenous Devonian deposits with different permeability. Method involves additional oil recovery using the existing stock of production and injection wells and taking into account the geological structure of the productive formation. Also, the method includes a stage in which pumping of the displacement agent is stopped when the extracted oil is flooded. Development of high-permeability non-clay reservoirs of the lower member of the formation is carried out at advanced rates in forced mode with compensation of fluid extraction by pumping of injected medium in range from 100 to 130%. When watering of extracted oil is more than 97% and production of at least 40% of oil from initial balance reserves, operation of lower packs of formations with high permeability is temporarily stopped and pumping of injected medium is stopped. Also, formations of the lower pack are stopped for gravitational separation of oil and water for period of 3 to 5 years. Well is changed over to development of the upper member of the formation with low permeability with compensation of more than 100% of the extracted liquid by pumping of the injected medium. As formation energy in the upper stratum of the formation is depleted, the well is transferred to the development of residual reserves of the lower stratum of formations.

EFFECT: increasing oil recovery of formations by transferring the development of oil reserves from the upper pack of formations to the period of reformation of residual reserves in the lower pack of formations of the Pashian horizon.

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