AN IMPROVEMENT IN PLACING CEMENT SLURRY IN WELLS IN THE PRESENCE OF GEOLOGICAL ZONES CONTAINING SWELLING CLAYS OR MUD RESIDUES CONTAINING CLAYS

摘要

The present invention seeks to improve placement of cement slurry in wells in the presence of geological zones containing swelling clays or mud residues containing clays. According to the invention, the well zone liable to contain water swelling clays is treated with a solution containing clay precipitating agents so as to coagulate the clay prior to the cement slurry being put into place during the cementing stage.