Patent ID: 6148913
Filing Date: 2000-11-21
Classification: C09K,E21B,Y10S

Abstract:
A process for minimizing the number of squeezing and shut-in operations needed to inhibit scale and thereby increase the production rate from an oil well using the precipitation squeeze method, said process comprising injecting into an oil-bearing rock formation matrix a water-miscible formulation comprising:(a) a water-miscible surfactant which is a glvcol ether 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 precipitation in situ in the presence of the cations in (b) upon injection into the rock formation matrix, wherein the minimum ion concentration of the scale inhibiting compound (c) is 5,000 ppm based on the total weight of the formulation, said components (a)-(c) being introduced either as a pre-formed single homogeneous composition, or simultaneously or sequentially in either order into the rock formation matrix.