Phase formation of oil-well cements based on chemical industry wastes

Abstract

The crystalline compounds CaAl2O4 and Ca12Al14O33 are reliably identified by electron microscopic and X-ray studies of the structural and phase features of clinker, and the iron- and chromium-containing phases are presented in the form of solid solutions: Ca2Al0.48Fe1.52O5 and Ca5(CrO4)(CrO4)2. This allows creating of a heat-resistant, strong, weighted oil-well cement for cementing “hot” oil and gas wells. It has been found that obtained materials have enhanced strength – compressive strength after 28 days of setting reaches 55 MPa, quick-setting – initial set – 2 hours 55 minutes, final set – 4 hours 20 minutes, quick-setting – compressive strength after 3 days of setting reaches 48.6 MPa, bending strength reaches 6.7 MPa; and are hydraulic binders with water-cement ratio of 0.17 – 0.38; with high sulfate resistance ratio of 1.31 which is 1.5 times higher than that of Portland cement.