二氧化碳驱引起管线穿孔的统计分析及防治措施

Statistical Analysis and Prevention Measures of Pipeline Perforation Caused by Carbon Dioxide Flooding

二氧化碳驱后柳赞北区管线穿孔频率明显增加,为查明原因,从管线类别、地理位置、穿孔影响因素及管线使用时间等因素进行了统计分析。结果显示,该地区管线频繁穿孔是受二氧化碳驱的影响,部分对应油井产出液中二氧化碳浓度较高,在集输过程中对管线造成腐蚀,导致管线穿孔;同时转油站不能成功地除去原油中高浓度的二氧化碳,使得掺水中二氧化碳含量累加,导致掺水管线穿孔。结合实际生产工艺流程,采取改换掺水来源、更换严重腐蚀管段、优化原油集输流程和化学防腐等措施,可极大地降低区域管线穿孔频率,对管线具有良好的保护效果。

After using carbon dioxide flooding, pipeline perforation frequency of Liuzan North area increases significantly. In order to find the reason, pipeline categories, geographic locations, perforation factors and pipeline using time are statistically analyzed and then verified by theories, practice and experiments. Results show that the frequent perforation in the area is caused by carbon dioxide flooding. Carbon dioxide concentration in produced liquid of some related oil wells is high, which causes pipeline corrosion during gathering and transporting process and then leads to pipeline perforation. Meanwhile, oil transfer stations cannot remove high concentration of carbon dioxide from the crude oil, which makes carbon dioxide in blending water accumulate and blending water pipeline perforate. Combined with actual production process, measures such as changing blending watered source, replacing seriously corrosive pipeline sections, changing gathering and transportation process and adding corrosion inhibitors are put Forward. They can effectively reduce frequency of pipeline perforation in the area and have good effect on pipeline protection.