METHOD OF WELLS CASING AND CEMENTING Russian patent published in 1996 - IPC

FIELD: insulation and separation of productive stratums. SUBSTANCE: aim is to provide increase of casing sealing and to prevent casing string collapse. Solidifying and nonsolidifying plugging back material is pumped in given place of casing string outside space, that obtains plastic properties after setting in well. For the purpose they using selection of components (hydrophobic liquid and thickeners) determine during modeling of stratum temperature capability of nonsolidifying plugging back material to obtain properties of plastic substance. Then part of thickeners is dissolved in hydrophobic liquid till nonsolidifying plugging back material viscosity is equal to solidifying plugging back material viscosity and before pumping-in rest part of thickener is added to allow full solution and formation of plastic substance to be realize in given place of casing string outside space. Method also provides for full dissolving of thickener in surface terms and viscosity adjustment is exercised using heating of nonsolidifying plugging back material. EFFECT: method allows to provide increase of casing sealing and to prevent casing string collapse. 3 cl, 1 dwg, 1 tbl