Precipitation of scale inhibitors in subterranean formations

A process to emplace a scale inhibitor within a brine containing subterranean formation in the vicinity of a producing wellbore comprising:

• providing an acidic aqueous solution comprising a dissolved scale inhibitor and a metal cation which combination is slightly soluble in the formation brine, a precursor which is capable of reacting within the formation to become a basic component and a chelating agent in an amount effective to prevent decomposition of the precursor upon contact with steel tubulars;
• injecting the acidic aqueous solution into the formation through the wellbore;
• and
• producing formation fluids from the wellbore after the precursor has generated an amount of basic material sufficient to cause an amount of the scale inhibitor and metal cation to precipitate within the formation that is effective to provide scale inhibition.