METHOD OF KILLING OIL AND GAS WELLS Russian patent published in 1998 - IPC

FIELD: oil and gas production. SUBSTANCE: when killing wells, solution pumped into the well contains 0.4-0.8 wt.-% of polyacrylamide and is radialyzed by the dose 0.5 to 2.5 Mrad. Solution is forced through by column of liquid providing bottom pressure exceeding formation pressure. Before aqueous solution of radialyzed polyacrylamide is applied, demuding fluid is pumped in. The latter is forced through into formation by buffer liquid. Volume of demuding fluid is twice as large as that of buffer liquid. Volume of solution of radialyzed polyacrylamide is superior to that of demuding fluid by a factor 1.5-2.5. EFFECT: prevented pollution of productive zone of formation and reduced consumption of material. 1 tbl