skip to main content

Attention:

The NSF Public Access Repository (NSF-PAR) system and access will be unavailable from 5:00 PM ET until 11:00 PM ET on Friday, June 21 due to maintenance. We apologize for the inconvenience.


Search for: All records

Creators/Authors contains: "Dong, Shiqi"

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. null (Ed.)
  2. Abstract

    Calcium nitrate (Ca(NO3)2) has been suggested to inhibit steel corrosion. However, the effectiveness of corrosion inhibition offered by calcium nitrate in highly halide-enriched environments, for example, completion fluids, is not well known. To better understand this, the inhibition of corrosion of API P110 steel by Ca(NO3)2was studied using vertical scanning interferometry in solutions consisting of 10 mass % calcium chloride (CaCl2) or 10 mass % calcium bromide (CaBr2), for example, to simulate the contact of completion fluids with the steel sheath in downhole (oil and gas) applications. The evolution of the surface topography resulting from the initiation and growth of corrosion pits, and general corrosion was examined from the nano-scale to micron-scale using vertical scanning interferometry. Special focus was paid to quantify surface evolution in the presence of Ca(NO3)2. The results indicate that, at low concentrations (≈1 mass %), Ca(NO3)2successfully inhibited steel corrosion in the presence of both CaCl2and CaBr2. Statistical analysis of surface topography data reveals that such inhibition results from suppression of corrosion at fast corroding pitting sites. However, at higher concentrations, calcium nitrate’s effectiveness as a corrosion inhibitor is far less substantial. These results provide a means to rationalize surface topography evolution against the electrochemical origin of corrosion inhibition by NO3species, and provide guidance regarding the kinetics, and susceptibility to degradation of the steel sheath during exposure to halide-enriched completion fluids.

     
    more » « less