METHOD FOR WATER INFLUX ISOLATION AND RESTRICTION IN WELL Russian patent published in 2006 - IPC E21B43/32 

FIELD: oil production, particularly to isolate casing annulus and tubing-casing annulus with the use of plugging polymer-based compositions curable in reservoir conditions.

SUBSTANCE: method involves injecting isolation material in injection or production well, wherein the isolation material includes polymer curable in reservoir conditions; forcing thereof through well and holding the composition inside well for time enough to cure and strength development. The composition is water-soluble polymeric composition including acetone-formaldehyde resin in amount of 80.0% by weight, sodium carbonate or potassium carbonate in amount of 4.0-7.0% by weight, chemical reagent Okzil-SM in amount of 0.5 % by weight, remainder is water or 30% NaCl solution. If reservoir temperature is 50°C or less alkali, namely sodium hydroxide NaOH, in amount of 0.1-2.5% by weight is additionally mixed with above composition. In the case of plugging operation performing in high-pressure wells fine inert filler, namely industrial talc, is added in amount of 30-100% of composition volume to be injected.

EFFECT: possibility of casing annulus and tubing-casing annulus plugging in temperature range of 20-90°C.

3 cl, 3 tbl, 3 dwg