METHOD OF TIGHTNESS RECOVERY OF WELL TUBING-CASING ANNULAR SPACE Russian patent published in 2000 - IPC

FIELD: oil-and-gas producing industry. SUBSTANCE: method is used in performance of repair and sealing operations in wells, particularly, in recovery of tightness of tubing-casing annular spaces in operation of deep oil, gas and gas-condensate wells. Method includes heating of casing string and tubing-casing annular space; injecting into annular space of sealing composition; cooling of casing string and annular space. Casing string and annular space is cooled prior to injection of sealing composition. For this purpose, well is shutoff. Casing string and annular space are heated after injection of sealing composition and well is brought into operation. Sealing composition is used in the form of polymer grouting material with solidification within temperature range of 65-100 C. EFFECT: higher sealing of annular space due to increased interval of filling of overflow channels with sealing composition and formation of channel of long-tern impermeable composition. 2 cl, 2 dwg