PROCESS FOR PREVENTING OR REDUCING ABSORPTION FORMATION OF OIL-BEARING ROCK Russian patent published in 1996 - IPC

FIELD: drilling of wells. SUBSTANCE: during the drilling operation, agent is added to the drilling mud. The agent permits reducing permeability of the rock being drilled in amount of up to 100% with respect to the volume of the drilling mud. Said agent is continuously flowing gel containing polyacrylamine or carboxylate containing acrylic polymer, chromium complex and aqueous solvent. The chromium complex is formed of at least one electrically positive cation CR⁺³, at least one electrically negative carboxilate anion and electrically negative oxygen or hydroxyl, or inorganic ion, or water molecule or mixture thereof. EFFECT: more efficient process for preventing or reducing absorption of drilling mud. 3 cl, 7 tbl