LIGHTENED GROUTING MATERIAL Russian patent published in 2003 - IPC

FIELD: lightened grouting materials; applicable in cementing of oil and gas wells. SUBSTANCE: lightened grouting material includes Portland cement clinker, fuel fly ash and siliceous additive, at least, one from group including tripoli, opoka, diatomite, gypsum and calcium chloride. In this case, Portland cement clinker has free calcium oxide within 0.5-3.0 wt.%. Fuel fly ash contains, at least, 35 wt.% of cilicon oxide, and, at least, 17 wt.% of aluminum oxide. Lightened grouting material has the following amounts of components, wt. %: said fuel fly ash 10-30; said siliceous additive 5-20; gypsum 3-8; calcium chloride 1-2; the balance, Portland cement clinker, but not less than 55 wt.%. EFFECT: better quality of well cementing with less bulk density of grouting mortar and presence of linear expansion and self-straining. 2 tbl