Method for scale inhibition in oil producing wells

摘要

A method for inhibiting scale formation in oil producing wells. The method comprises pretreating the rock formation of the near well bore area with a surface agent and then a saline solution by injecting these down the well bore. Subsequently the formation is treated with a source of divalent cations such as calcium. An acid inhibitor in the form of a polyacrylic acid derivative, a phosphonated or a phosphinopolycarboxylic acid is then injected into the rock formation and allowed to soak in for a period of 24 hours. The inhibitor is retained on the surface area of the rock formation by means of divalent cationic bonds.