GELLING COMPOSITION FOR ISOLATION OF LOST-CIRCULATION FORMATION Russian patent published in 1995 - IPC

FIELD: oil production. SUBSTANCE: composition, used for lost-circulation formation isolation, has, in mass treated with γ radiation polyacrylamide (РПАА) 0.7 0.9; ferrochromelignosufonate 2.0 2.6; balance water. РПАА is introduced in water, mixed and left for 1.5 hour. ФХЛС and ПАВ are added to the solution and stirred for 5 minuted. Introduced ratio of РПАА is taken as 1 mass particle per 2.0 2.6 mass particles of ФХЛС. Characteristic of the composition: isolating effect is twice as much due to increase of foam stability by 220 340 fold, decrease of water separation is one 7-th 10th as large, decrease of gelling time is one 20-th one 50-th of its previous value. EFFECT: increased effectiveness of isolation. 2 cl, 1 tbl