Abstract:
Every year about 100 thousand failures of field pipelines fixed in Russia, 90 % of which are somehow connected with the corrosive wear.
The authors propose a modernization of the standard scheme galvanic cathodic protection by placing the anode electrode is not in the ground, but directly inside the pipeline using as the electrolyte transported fluid. In this case, as a result of the oxidation - reduction reaction due to the potential difference the metal recovery takes place on the inner tube wall.
Apart from the standard electrochemical protection of the decay of the anode electrode leads to the formation of iron oxide Fe$_3$O$_4$, which should cover as the thin film the inner wall of the pipe, clogging the pores of the existing defects, microcracks and prevent contact with aggressive fluids.
To test the performance was designed and assembled anticorrosive module. Empirically chosen alloy (aluminum alloy with 45 % magnesium) casting the anode electrode.
The authors constructed testbench, tested by measurement of the corrosion rate by using the proposed method of protection. Experimental - field tests were carried out on production lines of JSC «Udmurtneft». The relative rate of corrosion of the pipeline without protection at steady state was 0.73 mm/year. The relative rate of corrosion of the pipeline with anticorrosive module was 0.45 mm/year. Thus, due to the anticorrosive module corrosion decreased by 62.5 %. The pipeline with anticorrosive unit is not prone to the formation of paraffin and salt deposits.
Keywords:corrosion, anticorrosive module, galvanic cathodic protection, electrode, field pipeline.
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