LIGHTENED GROUTING CEMENT AND A METHOD FOR PREPARATION THEREOF Russian patent published in 2007 - IPC C09K8/473 C04B7/12 

FIELD: oil and gas production.

SUBSTANCE: invention is designed for use in cementation of deep boreholes under complicated geologic conditions and on deposits in late development stage, in whose geologic profiles there are intake formations and formations in risk or rupture. Lightened grouting cement containing mixture of Portland cement, ashes or tripoly powder further includes microspheres not larger than 0.5 mm in diameter, above mixture has specific surface 9000-12000 cm²/g, and proportions of components are as following: cement 70-85%, ashes or tripoly powder 10-17%, aluminosilicate microspheres 5-13%. In a method of preparing lightened grouting cement by mixing Portland cement, ashes or tripoly powder, Portland cement having specific surface 2000-2200 cm²/g with ashes or tripoly powder are preliminarily crushed in disintegrator operated at particle concussion rate 90-140 m/sec and concussion frequency 4-5 per 10-3 sec to achieve above-indicated specific surface, after which mixture is mixed with aluminosilicate microspheres in screw-mixers or drums to obtain homogenous composition.

EFFECT: reduced density of cement mortar to 1300-1400 kg/m², reduced water loss of mortar, and increased strength and corrosion resistance of cement stone.

2 cl, 2 tbl