油气管道是国家能源发展的命脉,保持油气管道畅通是国家长久发展的基本保障.金属燃气管道的精准探测是实现管道安全畅通的必要手段,单一的地球物理方法难以满足管道的精准探测,本文提出瞬变电磁与基于静力触探的等电位体测试相结合的方法,实现燃气管道纵横双向探查.以安徽某场地为例,通过布置与疑似管道走向相垂直的多条瞬变电磁测线,确定每条测线两处低阻异常位置,将异常位置连接成线可基本定位管道走向,实现管道横向定位.结合瞬变电磁探测结果与场地静力触探施工条件,在疑似管线异常区域开展静力触探和等电位体测试,管道所在位置贯入阻力为0,电流密度最大,可达565 mA.现场实验表明:瞬变电磁法的横向异常位置圈定可减少验证孔的布置,基于静力触探的等电位体测试采用两种方法对管道的垂向深度进行定位,极大程度提高了管道定位的准确率,金属燃气管道的探测采用瞬变电磁与于静力触探的等电位体测试相结合的方法,可实现管道的精准定位.
Oil and gas pipelines as the lifeblood of national energy development,keeping oil and gas pipelines open is the basic guarantee for the permanent development of the country.Precise detection of metal gas pipelines is a necessary means to achieve safe and smooth pipe-lines,but solo geophysical method is difficult to meet the accurate detection of pipelines.In this paper,a method combining transient electromagnetic and equipotential body test based on static sounding is proposed to realize vertical and horizontal two-way detection of gas pipelines.Taking a site in Anhui province as an example,by arranging multiple transient e-lectromagnetic survey lines perpendicular to the direction of the suspected pipeline,two low-resistance abnormal positions of each survey line are determined.Connecting the abnormal position into a line can basically locate the pipeline direction and realize the horizontal positio-ning of the pipeline.Combined with the results of transient electromagnetic detection and site construction conditions,static sounding and equipotential body test are carried out in the suspected abnormal area of pipeline,the penetration resistance at the location of the pipe is 0,and the current density is up to 565 mA.The field experiment shows that the arrangement of verification holes can be reduced by delineating the lateral abnormal position of transient e-lectromagnetic method,and the equipotential body test based on static sounding uses two methods to locate the vertical depth of the pipeline,which greatly improves the accuracy of pipeline positioning.The detection of metal gas pipeline can achieve the precise positioning of the pipeline by combining transient electromagnetic and equipotential body test based on stat-ic sounding.