Valence Effect : In general, the higher the valence of an ion the greater the loss of stability to emulsions, colloidal suspensions etc., these polyvalent ions will impart. (Bul D11)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}