2 results about "Pitting corrosion" patented technology

Provided are a viscous acid and a preparation method thereof. The preparation method includes: adding 60.00-81.25 parts of water, 15.00-25.00 parts of 31% dilute hydrochloric acid, 0.25-1.00 part of biological activator, 0.50-4.00 parts of an acidizing corrosion inhibitor and 1.00-5.00 parts of an iron ion stabilizer into a container, dropwise adding 2.00-5.00 parts of acidizing thickener THICK-B100 under stirring, and mixing well to form a viscous acid solution; the viscous acid is 4 to 5 times as high as a conventional acid in retarding action, never causes pit corrosion near a shaft, and may cause long cracks that have excellent flow guide capacity; viscous acid gel-breaking liquid is lower than 30 mN/m in surface tension and never causes water blocking damage during flowback.

The invention discloses a spraying method for an electric arc spraying coating of a well drilling water string and a hole sealing coating thereof. The spraying method comprises the steps that a protective coating is prepared on the surface of a water string base body by an electric arc spraying process, and at the same time, the hole sealing coating is sprayed, and the protective coating of the surface of the water string with high hardness, wear resistance and pitting corrosion resistance is obtained. The service life is effectively prolonged, and the cost of use and maintenance is reduced.