METHOD FIXING OIL AND GAS WELLS Russian patent published in 2003 - IPC

FIELD: oil and gas production, stabilization of wells with corrosive and active stratal water, gas and gas-water-oil fluid. SUBSTANCE: according to invention casing string is cemented in well. At least one length of casing string located in zone of possible exposure to corrosive media is implemented in the form of one or several corrosion-resistant casings. After injection of calculated volume of cement mortar intervals of possible action of corrosive media and productive pools are limited with the help of separators with formation of reinforced cement stone in zone of location of the latter. Tubes made of steel brand 09 ГСΦ or of stainless steel are used in the capacity of corrosion-resistive tubes. Outer surfaces of tubes bordering on corrosion- resistive tubes are treated with anticorrosive coat before sinking of casing string. EFFECT: increased reliability of well fixing with provision for long service life of casings located in interval of action of corrosive media, protection of adjacent casings bordering on these casings against corrosive action of corrosive media, increased time between well overhauls and reduced scope of repair and insulation operations. 1 cl, 3 dwg