Multicomponent thermal fluid flooding has become a widely used and very effective heavy-oil recovery technology, but the harsh CO 2 -O 2 -Cl − environment can lead to serious corrosion perforation failure of the pipeline. Therefore, the influence of O 2 content and main controlling factors on corrosion perforation were investigated through a weight-loss experiment, corrosion defect test, characterization and grey correlation method. The results showed that, with the increase in O 2 content, the general corrosion rate and localized corrosion rate increased. The uneven protection performance of the product after the addition of O 2 was found to be the key cause of localized corrosion. In addition, the synergistic effect of O 2 -Cl − promoted the lateral and longitudinal expansion of pits. The results of the grey correlation showed that the temperature (30-120 °C) had a greater impact on localized corrosion compared with the content of O 2 (0-0.045 MPa) and Cl − (0-16,000 mg/L).
For long-distance natural gas pipes crossing highway, the changing load of vehicles is the most important and frequently acting-live load on buried pipes, which poses a serious threat to the integrity of the pipe. This study has designed and built a buried pipe stress test experimental system. The experimental system is mainly composed of a sealed pipe, an air compressor, and a stress-strain testing system. In this study, a total of 24 sets of stress test experiments are carried out. The research conclusions are as follows. The maximum stress of the pipe occurs at the 12 o’clock position of the pipe when the vehicle load is rolled at the middle. The increase in vehicle load results in an increasing pipe stress value. Both of the vehicle speed and the internal pressure play a certain role in protecting the pipe. After carrying out a real experimental case via Sinopec’s natural gas pipe crossing the highway, we have found that it can withstand the rolling load of a heavy vehicle of 78t, when the L325 steel pipe section that crossing the Grade-4 highway has a buried depth of 0.8m, a diameter of 355.6 × 5.6mm, and a internal pressure of 1.03MPa.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.