Cementing compositions and the application of such compositions to cementing oil or analogous wells

摘要

The invention concerns cementing compositions, particularly for squeeze cementing, comprising a liquid phase and a solid phase constituted by particulate materials which are insoluble in said liquid phase, in particular a microcement. The compositions of the invention comprise additives of a nature and composition such that variations in viscosity of the composition due to fluid loss are minimized. Preferably, the compositions comprise at least one “very fine” additive formed from particles which are smaller than the cement, with a ratio of the average grain sizes of the particles of said additive and those of the cement in the range 5 to 100, preferably about 10, the respective proportions of the solid particles corresponding to a packing volume fraction close to the maximum, and the porosity of the solid mixture being such that the mixture is in a state of hindered settling.