HYDROGEN SULPHIDE RESISTANT GROUTING MORTAR Russian patent published in 2013 - IPC C09K8/467 

FIELD: oil and gas industry.

SUBSTANCE: hydrogen sulphide resistant grouting mortar contains Portland cement, sand, weighting material, water-repelling agent and liquid for pre-mixing and differs by the fact that it also contains Mikrodur-261R-X, regulating agents of process properties- superplasticising agent C-3 and nitrilotrimethylenephosphonic acid, weighting material of thermal corrosion protection - ethyl silicate, and sulphanole as water-repelling agent and barytic concentrate as weighting material, fine quartz sand with specific surface of 5000-8000 cm²/g as sand at the following component ratios, wt %: Portland cement 60-30, Mikrodur-261R-X 2-4, sand 1-2, superplasticising agent C-3 0.3-1, nitrilotrimethylenephosphonic acid 0.05-0.2, ethyl silicate 1.4-2.3, sulphanole 0.25-0.5, weighting material 5-35, and liquid for pre-mixing 30-25.

EFFECT: obtaining sedimentation resistant system with water sedimentation close to zero with further formation of corrosion-resistant stone with unchangeable volume during long period of time and with back pressure on formations and walls of the well shaft, which is equivalent to overburden pressure, which allows reliable cementing of casing strings in wells with flows of hydrogen sulphide, brine.

4 cl, 1 tbl