Well treating composition and method

Abstract From the Canadian patent

There is disclosed a method of treating a subterranean substantially carbonate-free sandstone formation associated with a well completed in said substantially carbonate-free sandstone formation comprising displacing into said formation through said well an effective amount of an acidic aqueous solution comprising from about 5 to about 36 weight % phosphoric acid, from about 0.6 to about 5 weight % of a highly polar surface active agent which is a citric acidmonoethanolamine elimination reaction product and an, effective amount of a ferrous metal corrosion inhibitor. For treating a subterranean limestone or dolomitic formation or a sandstone formation having a substantial carbonate content …