BACKFILL MAGNESIUM-CARNALLITE MIXTURE Russian patent published in 2017 - IPC C09K8/467 C04B28/30 C04B22/16 C04B24/12 C04B103/60 

FIELD: construction.

SUBSTANCE: invention relates to cementing casing strings in oil, gas and gas-condensate wells opening salt rocks and formations with polymineral waters of high mineralization. Invention can also be used in cementing pipe strings in saltless intervals and for installation of insulating cement bridge plugs. Backfill magnesium-carnallite mixture contains caustic magnesite powder, carnallite chlorinator sludge, a fine inorganic additive, sodium tripolyphosphate, carbamide and water in the following proportions, wt%: magnesite caustic powder 22.88–37.29, carnallite chlorinator sludge 22.22–36.79, a fine inorganic additive 6.35–11.43, sodium tripolyphosphate 0.32–0.65, carbamide 1.27–3.27, water – the rest. Fine inorganic additive used in the backfill magnesium-carnallite mixture is either blast-furnace granulated ground sludge, or thermal power plant fly ash, or pulverized ground quartz.

EFFECT: technical result is receiving a backfill magnesian-carnallite mixture excluding the need for preparing a special composition of the tempering liquid and allowing the use of standard technology of tempering water to produce a solution, the stone of which is characterized by high corrosion resistance in polymineral brines of high mineralization.

1 cl, 1 tbl