WEIGHTED GROUTING MORTAR Russian patent published in 2016 - IPC C09K8/48 E21B33/138 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to backfill mud used when casing cementing deep oil and gas wells in range of abnormally high formation pressures and temperatures. Weighted grouting mortar contains portland cement grouting, weighting additive and water. Weighted grouting mortar as weighting additive contains a galenite concentrate from lead ores, as hardening retarder - nitrilotrimethylphosphonic acid, additionally Natrosol 250 EXR in following proportions, wt%: portland cement 53.85-50.0, galenite concentrate from lead ores - 23.05-26.92, nitrilotrimethylphosphonic acid - 0.015-0.03, Natrosol 250 EXR - 0.11-0.08, water - balance.

EFFECT: high density and sedimentation stability, longer time of pumping ability of weighted grouting mortar at high temperatures while providing other technological parameters of solution and stone.

1 cl, 2 tbl