BASE COMPOSITION FOR BOS GROUTING MORTARS, GROUTING MORTAR AND METHOD OF WELL CEMENTING Russian patent published in 2003 - IPC

FIELD: well drilling, particularly, reagents for regulation of compounding properties of grouting mortars used in casing and cementing of oil, gas and water wells. SUBSTANCE: base composition for grouting mortars contains water-soluble cellulose ether from group including methyl cellulose, carboxymethyl cellulose, oxyethyl cellulose, carboxymethyl-oxyethyl cellulose, polyanion cellulose and oligomer glycol with molecular weight of 1000-2000 from group: oligomer polyoxyethylene glycol or polyoxypropylene glycol, or oligomer copolymer of ethylene oxide and propylene oxide, or ether of oligomer ethylene oxide, or ether of oligomer propylene oxide, ether of oligomer copolymers of ethylene oxide and propylene oxide, with the following ratio of components, wt.%: water-soluble cellulose ether, 95.0-99.9; oligomer glycol, 0.1-5.0; possible also additionally plasticizers - setting retarder, 0.1-5.0; or setting accelerators, 1.0-4.0. Base composition may be added to grouting mortar in amount of 0.5-2.0 wt.%. Grouting mortar containing cement and said base composition may also have at least one plasticizer in amount of 0.1-0.5%, or at least one setting accelerator in amount of 0.1-4.0%. Said grouting mortar is used in said method of well cementing. EFFECT: effective base composition for production of grouting mortars with high insulating ability, reduced water losses and absent foaming, increased reliability of well cementing, preserved minerals. 9 cl, 2 tbl