TECHNOLOGY OF REPEAT OPENING OF STRATUM Russian patent published in 2002 - IPC

FIELD: mining industry, oil and gas production, running of wells with opened carbonate collectors. SUBSTANCE: technology embraces primary perforation of water-saturated stratum located above oil-saturated pool. Packer is set above primary perforation. Water insulation composition is injected through primary perforation and primary perforation is pressure grouted with the help of cement bridge. First bath of reagent dissociating clay is formed in well. First bath is forced through perforation zone into oil-saturated pool by means of pressure fluid-mineralized water with density from 1.05 to 1.10 g/cu cm. Solution of reagent of dissociating clay is aged in the course of 18 h as minimum. Pressure fluid and first bath of reagent dissociating clay is forced out by swabbing. Products of reaction of solution of reagent dissociating clay with clayey minerals in mixture with oil are recovered from oil-saturated pool in volume larger by factor of 1.2 as minimum than volume of first bath. Second bath of solution of acid with reagent stabilizing clay is formed in same perforation zone of oil-saturated pool. Second bath is forced by pressure fluid through perforation zone into oil-saturated pool, is aged there and removed. EFFECT: recovery of water-free oil, preservation of hydraulic conduction of oil-saturated pool and prevention of fall of oil discharge due to sedimentation in collector. 6 cl, 4 dwg