BACKFILL COMPOUND Russian patent published in 2023 - IPC C09K8/467 C04B28/04 

FIELD: oil and gas industry.

SUBSTANCE: cement mixtures intended for cementing oil and gas wells covering intervals of permeable formations at elevated temperatures. The cement composition includes, wt.%: Portland cement PCT-I-50 62.1-62.2; water 31.2-31.4, as carbon black, a mixture of nanoadditives 0.3-0.45; silica smoke 6.0-6.4. The mixture of nanoadditives comprises Graphene Oxide GLC-GO, Carbon nanotubes CAS 308068-56-6, Nanosilica OSCh CAS 112926-00-8 at the following ratio in wt.% of the mass of the cement composition: 0.1:0.1:0.1, or 0.15:0.1:0.1, or 0.15:0.15:0.1, or 0.15:0.15:0.15 respectively.

EFFECT: increasing the efficiency of well casing under conditions of elevated temperatures.

1 cl, 1 tbl, 16 ex