STUDY AND APPLICATION ON NEW ANNULAR PROTECTING FLUID CORROSION

Modified mud annulus protection fluid, low solid annulus protection fluid and pure salt annulus protection fluid are in common use after well completion because of their simple use and low cost. Oil base annulus protection fluid is not corrosive, however, its high cost and environment pollution restricts its universal use. After compared with other organic salts, Weigh2 and Weigh3 organic salts solution are selected for study. Through hanged up metal corrosion experiment, metal self corrosion experiment, stress corrosion cracking experiment and rubber sample hardness and weight influence experiment, the two organic salts both attend to prevent corrosion and protect annular tubes. These two organic salts solution have been applied in 6 wells as annulus protection fluid. Results show that the fluids are very effective, economic and have no pollution.