Erosion-Corrosion Study of Oil-field Materials due to Liquid Impact

摘要

The goal of this work is to determine erosion-corrosion damage caused by liquid impacts in the oil and gas industry. The American Petroleum Institute Recommended Practice 14E (API RP 14E) guide describes a method for calculating an erosional velocity for clean service. Some authors believe that the basis for API RP 14E is erosion due to liquid droplet impacts. The API correlation is very simple and as noted in the literature does not contain many factors contributing to erosion-corrosion. A series of experimental data was collected for specimens from oilfield materials impacting liquid jets in a test configuration that conforms to American Society for Testing and Materials (ASTM) standard G73-10. Specimens were mounted on a rotating disk and impact the liquid jet periodically. The tests were conducted with two solutions, aerated 3% NaCl brine and tap water at two impact velocities, 52 and 26 m/s. It was observed that the weight loss of low chromium alloys was higher than the weight loss of corrosion resistant alloys especially when brine was used as the erodent solution. The weight loss is then converted to Erosion-Corrosion Ratio which is defined as the ratio of volumetric loss of the specimen to the total volume of the fluid that is impinged. A correlation has been proposed based on the erosion correlation from ASTM G73-10 to calculate the erosion ratio of the materials for different configurations and verified with experimental data from literature. The calculated threshold velocity using the data and method developed in this study are compared for several different flow conditions with the API RP 14E. It is shown that the trend of the erosional velocity calculated by the API guideline does not correlate with erosion-corrosion caused by liquid impact.