PRETREATED CLAYS, THEIR PREPARATION AND USE IN FORMULATING DRILLING MUDS NOT AGGRESSIVE TO LAYER CLAYS

摘要

Disclosed is a process for preparing aqueous, clay-based muds, not aggressive to layer clays, which process comprises a first step in which clay is treated with an aqueous solution containing the necessary amount of dispersant to fluidify the mud; a second step, of separation of so treated clay from the aqueous solution containing any not adsorbed dispersant, and, finally, a step of re-dispersion of so treated clay in water, in order to formulate the mud.