BASE OF CURABLE GROUTING MORTAR Russian patent published in 2012 - IPC E21B33/138 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to the base of curable grouting mortar used for filling in the inner volume of open and cased shaft of the well between permanent bridges, grouting fluid-resistant covers and screens during well abandonment process, as well as at isolation of productive horizons and long-term preservation of wells in formations with abnormally high formation pressure (AHFP) and availability of corrosive components of hydrogen sulphide and carbon dioxide in the product. Base of curable grouting mortar includes grouting Portland cement, regulating agents of process properties and densifier. In addition, it contains finely dispersed binding agent, clay and hydrogen sulphide neutraliser. Superplasticising agent C-3 and nitrilotrimethylenephosphonic acid is used as regulating agents of process properties at the following component ratios, wt %: grouting Portland cement 4.0-22.0; densifier 85.55-60.05; superplasticising agent C-3 0.4-3.0; nitrilotrimethylenephosphonic acid 0.05-0.45; finely dispersed binding agent 1.5-3.0; clay 3.0-4.5; hydrogen sulphide neutraliser 5.5-7.0.

EFFECT: increasing isolation efficiency.

5 cl, 1 tbl