POROUS EXPANDING CEMENT MATERIAL Russian patent published in 2024 - IPC C09K8/46 C04B28/04 C04B111/76 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to cementing materials for cementing casing strings in gas, gas condensate and oil wells, complicated by the presence of permeable, fractured and permafrost rocks. Porous expanding cement material, including additive-free Portland cement “ПТЦ I-50”, lightening and expanding components, which are low-temperature expanded clay, construction hydraulic lime, an air-entraining additive, which is sodium alkyl sulphate, as well as superplasticizer MELFLUX 1641 F, mixing liquid, for which process water is used, and additionally, as a setting time regulator, dispersing alumina, with the following component ratio, wt.%: additive-free Portland cement - 68.0-72.0, low-temperature expanded clay - 15-20, construction hydraulic lime - 8- 10, dispersing alumina - 2.0-5.0, sodium alkyl sulphate - 0.001-0.004; MELFLUX 1641 F - 0.03-0.07, process water - balance, while the mixing liquid, superplasticizer and air-entraining additive are added to the composition in excess of 100%.

EFFECT: improved quality of primary cementing of casing strings under the conditions of negative, low positive, and normal temperatures.

1 cl, 1 tbl