| 摘要 |
<p>The invention relates to the oil and gas extraction industry, in particular to methods for expelling unrecovered oil, said methods reducing the permeability of flooded strata, drawing oil-saturated sections of low permeability into development and increasing oil recovery. The technical result of the invention consists in creating an effective method for controlling the permeability of a heterogeneous oil stratum by reducing the permeability of zones of high permeability of a water-saturated reservoir. The method for controlling the permeability of a heterogeneous oil stratum comprises pumping an aqueous suspension of sludge into the stratum - the sludge being a waste product of the production of sodium carbonate from Dorr settling tanks between separating banks of fresh water, pressing said sludge through together with the bank of fresh water in a volume equal to the volume of the above-mentioned suspension and shutting the well down for 24 hours. As the above-mentioned aqueous suspension of sludge - a waste product from the production of sodium carbonate from Dorr settling tanks, use is made of a sludge from the final production stage having the following composition, g/l: calcium carbonate - 80.0-90.0, calcium hydroxide - 2.0-10.0, magnesium hydroxide - 4.0-5.0, calcium sulphate - 0.4-0.6, sodium chloride - 300, sodium hydroxide - 2.0, the remainder comprising impurities and water. Mineralized waste water with a density of 1.107 g/cm3 is additionally pumped in.</p> |
