High temperature retarder for ölbohrlocherzemente, cement slurry and associated cementing

摘要

The invention relates to the cementing wells high temperature. & br / the delay device consists of a derivative methylenephosphonic) acid and boric acid or a borate at least as the acid chloride borax in aqueous solution, in particular of sodium pentaborate, in the preferred ratio of 0,08 to 0,92 parts by weight. & br / are obtained simultaneously a long time and a very rapid development of resistance to compression.