Abstract
The corrosivity of CO2 containing water used for injection into formations is very high. One of the means for mitigating this corrosion is through the use of internal Fusion Bonded Epoxy (FBE) pipe coatings. However, these are very demanding services for coatings. Pressures and temperatures are high enough in some cases to severely stress the coating. Most FBE coatings are permeated by CO2, and when pressures are released, blistering of the coating may occur. This compromises the integrity of the coating which may result in premature failure of the coating followed by corrosion of the pipe metal. The identification of coatings with good performance is absolutely essential. The failure of the coating alone can result in great losses due to the initial cost of the coating application, plus potential operating problems. When corrosive penetrations of the pipe occur, the costs escalate even higher as a result of required maintenance and down time.
This paper will describe the test work conducted to determine how to evaluate coatings for such services, and to determine which coatings will give successful, long-term performance. Test methods contained in an industry standard have been validated, and suitable coatings identified. Future test work needed to add to these findings has also been recommended.
Although this work was designed for CO2 services, it does give valuable insight into tests that are required to properly qualify FBE coatings for non-CO2 services.