LIGHTWEIGHT PLUGGING COMPOSITION Russian patent published in 2016 - IPC C09K8/473 

FIELD: oil and gas industry.

SUBSTANCE: invention can be used in cementing production string of upper over-producing intervals of well with backfill material with addition of foamed glass. Lightened grouting mortar for cementing over-producing intervals of upper well includes grouting portland cement, lightweight additive in form of foamed glass, water loss reducer and an antifoaming agent, foamed glass is selected with fractional composition 0.4-1 mm, water absorption in volume of 2-10 % and bulk density of granules 400±50 kg/m³, as reducer water loss composition contains polyvinyl acetate grade BP-08, and antifoaming agent is low-viscosity silicone antifoaming emulsion Penta 463, with following component ratio, wt%: grouting portland cement - 100, and over 100 % foam glass - 17-23, water loss reducer - 0.3-0.6, antifoaming agent - 0.04-0.06.

EFFECT: broader technological capabilities of using cement composition due to change of range of density while maintaining high strength of cement stone and high adhesion strength.

1 cl, 1 ex, 1 tbl