METHOD AND LIQUID FOR PLUGGING OF WELL Russian patent published in 1998 - IPC

FIELD: oil and gas production industry. SUBSTANCE: this is used in carrying out subsurface and overhaul repairs in abnormal conditions: high permeability of productive bed, superabsorption of well liquid, high gas factor both in injection and producing wells. According to method, perforation interval is blocked by replacing well liquid with plugging liquid and pressing liquid of density less than density of plugging liquid. Proportion of plugging liquid is pressed into down-hole zone of bed. Amount of plugging liquid is determined proceeding from coefficient of well productivity. Plugging liquid incorporates water-soluble calcium salt, free ammonia, production waste from wood-pulp and paper industry on base of lignosulfonates. Additional component is wood flour. Ratio of components is as follows, mas.%: water-soluble calcium salt, 12.4-43.5; free ammonia, 0.1-2.0; production waste from wood-pulp and paper industry on base of lignosulfonates, 5.0-25.0; wood flour, 4.0-12.0; water, the balance. EFFECT: high efficiency. 2 cl, 3 tbl