Cement slurries, unaffected by salts of magnesium, for cementing wells traversing salt formations, and related cementing processes

摘要

The slurries according to the invention contain: 18% NaCl; Na silicate and an agent of compatibility with magnesium consisting of H. sub. 3 PO.sub.4 and HEDP diphosphonate.PPThickening time is not affected by the presence or absence of salts of magnesium, up to 30% of bischofite equivalents. The rheology of the slurry and the compressive strength of the cement are also practically unaffected by magnesium contamination or the lack thereof.