METHOD OF PREPARATION OF LIGHT-WEIGHT GROUTING MORTAR Russian patent published in 2003 - IPC

FIELD: well construction. SUBSTANCE: method includes mixing of oil-well Portland cement with aluminosilicate microspheres and subsequent introduction into produced dry mix of mixing fluid containing cement setting accelerator and water, and their mixing. Mixing of oil-well Portland cement and aluminosilicate microspheres is effected in weight ratio of (80:90)-(10:20). Mixing fluid additionally contains oxyethylcellulose or hydrooxyethylcellulose and lignosulfonates or reagent based on melanine with the following their relation to weight of said dry mix, wt.p.p.: cement setting accelerator 0.2-3.0; oxyethylcellulose or hydrooxyethylcellulose 0.3-0.5; lignosulfonate or reagent based on melanine 0.1- 0.4; water 44-50. After introduction of mixing fluid, mixing is carried out for 0.5h. EFFECT: provided imparting to prepared mortar of high sedimentation stability, good pumpability, lower filtrate loss, controlled terms of setting and time of thickening, higher strength to cement stone with thickening, higher strength to cement stone with improved adhesion properties and low permeability. 2 tbl