带状镁合金牺牲阳极在库鄯输油管线阴极保护中的应用

APPLICATION OF MAGNESIUM RIBBON ANODE FOR CATHODIC PROTECTION OF OIL PIPELINE FROM KURLE TO SHANSHAN

根据φ３７７埋地管道工业规模预备试验的初步结果，在土壤电阻率相当高的新疆库鄯输油管道工程中，分别依靠三组长１０００ｍ的带状镁合金牺牲阳极，在两个相邻的测试桩上以两根并联（２×２５０ｍ）或四根并联（４×１２５ｍ）的方式埋设，使得长８１ｋｍ、１３１ｋｍ和１０７ｋｍ的三处φ６１０长输管段受到了有效的阴极保护。

For external corrosion protection of the newly constructed 610mm oil pipeline from Kurle to Shan-shan in Xingyiang, a combination scheme of high quality coating and cathodic protection executed partiallyin sacrificial anode mode was designed. Due to the high resistivity of soil in this region, extruded mag-nesium ribbons instead of traditional cast ingots were selected as sacrillcial anodes. Conventionallyt thecontinuous ribbon anodes were installed lengthwise in a trench parallel to and of the same length as thepipeline to be protected. In this project, however, only a short section of ribbon anode was found sufficientto provide a high level of protection for a considerably longer pipeline. Such a special configuration waspreliminarily verified on a 377mn pipeline in Shandong and then put into practice in Xingjiang.Twogroups of anodes consisting of 2 x 250m or 4x 125m ribbons were installed respectively at two test stationsseparated about 1kin. Potential measurements indicated that successful protection was achieved along thepipeline longer than 80km.