A method for inhibiting the formation, deposition and adherence of scale to metallic and other surfaces in the equipment, vessels and/or piping of facilities for the handling of oil and gas produced fluid is disclosed. An effective scale inhibiting amount of alginate is added to a produced fluid containing a scale-forming divalent cation. The alginate effectively cross-links with a scale-forming divalent cation, e.g., calcium, forming an alginate gel for subsequent separation and removal from the produced fluid.