定向钻穿越中管道防腐层损伤探讨

Pipeline Anticorrosive Coating Damage in Directional Drilling Crossing

定向钻穿越技术日趋成熟,常应用于国内外管道建设,但实施过程中不可避免地会对防腐层造成损伤,降低损伤成为关键。以塔中处理厂至轮南输气管道塔里木河定向钻穿越工程为例,介绍了定向钻穿越施工工艺、防腐层损伤评定、保护措施等内容;以及定向钻穿越施工完成后利用PCM采用电流衰减法评估定向钻穿越对管道防腐层的损伤程度,分析因防腐层损伤对整条输气管道阴极保护系统产生的影响。通过分析定向钻施工工艺,发现管道在定向钻穿越中,由于洗孔、泥浆配比、回拖等施工工艺不当都会造成防腐层大量损伤。为减少定向钻穿越管道防腐层损伤,从提高施工工艺精度和增加防腐层保护措施两方面加以改进,确保穿越段管道防腐层的完整性。

Introduced is the construction technology process of double gas pipeline directional drilling crossing project under the Tarim River. After crossing completion,applied is the current attenuation method through PCM to evaluate damage degree of pipeline anticorrosive coating during directional drilling crossing construction,analyzed are negative effects of the damaged anticorrosive coating on effective operation of the cathodic protection system in the entire gas pipeline and identified are causes of a lot of pipeline anticorrosive coating damage resulted during crossing construction and proposed are some anticorrosive coating protection measures,which will provide valuable reference for future directional drilling crossing projects.