Study Of Local Erosion-corrosion Of Pipeline Steel Under Multiphase Flow Of Oil/Water/Sand

Owing to the oil, water and sand contained in the fluid, gathering pipelines in the oilfieldencounter serious erosion-corrosion damage. Combining the in-suit condition of the oilfield tostudy the erosion-corrosion mechanism, to providing the controlling measures of themultiphase flow erosion-corrosion directly is meaningful in guiding the safety production. Anapparatus that could be used to launch both pipe loop and jet flow erosion-corrosion testsunder multiphase flow conditions was designed and constructed to launch the localerosion-corrosion experiments. Tests of20#pipe steel under different velocities, different sandconcentration, different impact angles and different angle position of the same pipeline crosssection were carried out using the apparatus, together with weight loss methods, normalelectrochemical tests and WBE. Erosion-corrosion mechanism of20#pipe steel undermultiphase flow was also investigated. In addition, numerical simulation was used tocharacterize the local erosion-corrosion. Conclusions are as follows:1) During the pipe loop erosion-corrosion tests, local corrosion of20#steel was found inoil/water, added solid particles enhanced local feature of corrosion greatly. Pure corrosion andpure erosion ranked47.50percent and70.83percent of the total erosion-corrosion in the20#steel-oil/water/sand (2wt%,40-60mesh) system with the velocity of2m/s at ambienttemperature, respectively. Negative synergism was observed, corrosion inhibited the erosiveweight loss by35.00percent, but erosion enhanced corrosion by16.67percent.2) During the jet flow tests, both distribution of local corrosion and the potentiation ofadded solid particles on local corrosion were quantified and characterized with the WBE.3) Flowfield numerical simulation was found helpful in interpreting the jet flow test result means that numerical simulation is potential in investigating local erosion-corrosionunder multiphase flow conditions. What’s more, numerical simulation will contribute topredicting local erosion-corrosion.