Abstract: A method for inhibiting oilfield scale formation including calcite in a high brine environment comprises introducing an effective amount of a scale inhibiting composition to a high brine environment susceptible to calcite scale formation. The environment has a total dissolved solids content of at least about 150 g/l, and the scale inhibiting composition comprises an aminomethylene posphonate of the formula ##STR1## wherein x is 2 or 3, each Z is independently selected from among H and CH.sub.3, and R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are independently selected from among hydrogen and --CH.sub.2 PO.sub.3 M.sub.2 wherein the M's are independently selected from among the hydrogen and cations associated with Lewis bases, such that at least about 80% of the R.sup.1, R.sup.2, R.sup.3, and R.sup.4 in the composition is --CH.sub.2 PO.sub.3 M.sub.2.

Abstract: Oil-in-water emulsions are resolved by contacting the emulsion with a polymer of vinyl phenol or a salt thereof. The polymers may be made by hydrolyzing polyacetoxystyrene.