WEIGHTED EXPANDING GROUTING MORTAR Russian patent published in 2001 - IPC

FIELD: grouting mortars applicable in cementing of casing strings in deep oil wells, in intervals of abnormally high formation pressures and temperatures. SUBSTANCE: weighted expanding grouting mortar contains ingredients in the following amounts, wt.%: Portland oil-well cement 20.50-36.55; iron ore concentrate 46.60-33.55; ferrochrome lignosulfonate 0.35-0.15; caustic magnesite powder 6.00-3.00; the balance, water. EFFECT: higher uniform expansion of grouting mortar and stone in time, increased strength of contact with metal of casing pipes. 2 tbl, 3 ex