GROUTING MORTAR FOR CONSTRUCTION AND REPAIR OF GAS AND OIL WELLS IN LOW TEMPERATURE CONDITIONS Russian patent published in 2021 - IPC C09K8/46 E21B33/138 

FIELD: oil, gas and coke-chemical industries.

SUBSTANCE: invention relates to oil and gas industry. Cement mortar for construction and repair of oil and gas wells in low temperature conditions contains 50.0-65 wt. % of alumina cement, 4.0-19.0 wt. % of metakaolin, 0.1-1.0 wt. % of plasticiser, 0.001-0.01 wt. % of setting accelerator and water up to 100 %. Plasticizer used is a superplasticiser Melflux PP100F, and the setting accelerator used is potassium carbonate, or sodium carbonate, or lithium carbonate.

EFFECT: technical result is provision of controlled time of thickening and setting time in conditions of low temperatures, as well as production of cement stone of high strength.

1 cl, 3 ex, 1 tbl