摘要 |
<p>This invention is a process and a formulation for minimising the squeezing and shut-in operations needed to inhibit scale in a production well using the precipitation squeeze method by injecting into an oil-bearing rock formation a water-miscible formulation comprising: (a) a water-miscible surfactant which is in liquid form, (b) a solution of water-soluble metal salt comprising a multivalent cation and (c) a solution of a water-miscible scale-inhibiting compound comprising an anionic component capable of forming a scale-inhibiting precipitate in situ in the presence of the cations in (b) upon injection into the rock formation, wherein the surfactant is a glycol ether and the minimum ion concentration of the scale-inhibiting compound (c) is 5000 ppm based on the total weight of the formulation.</p> |