METHOD TO TREAT CRITICAL ZONE STRATUMS , LAID BY TERRIGENOUS CLAY-CONTAINING ROCKS Russian patent published in 1995 - IPC

FIELD: oil extracting industry. SUBSTANCE: method to treat critical zone stratum provides for pumping in stratum first 0.1 7.5 concentration reducer in volume of 0.5 1.0 of pores volume and then oxidizer. As oxidizer they use concentrated sulfuric acid in volume of 25 of pores volume. Dichloride of tin, sodium thiosulfate, sodium sulfate, sodium sulfite or hydrogen sulfide containing waste water with share of dissolved hydrogen sulfide of 0.014 0.024 mass and density of 1,1-1,13 g/cm³. EFFECT: method allows to stabilize water-sensitive clays and to increase efficiency of reduction of initial permeability of critical zone of stratums, laid by terrigenous clay-containing rocks. 2 cl, 3 dwg