Geophysical Technology In The Application Of The Buried Pipeline Leak Detection

Existing leakage control technology at home and abroad mostly are negative pressure wave and relevant analysis technology,although can be buried pipeline monitoring and leaking positioning,roughly but unable to pinpoint specific leak.If it is not found the leak point in time after buried pipeline leak,extremely easy to cause further loss;If the leak is flammable and explosive medium,that once into the limited space,and it may even cause serious safety accidents.Now,Regular testing project of buried pipeline mainly includes Pipeline anticorrosive coating protection status,the effectiveness of cathodic protection etc.,the main technology are alternating current gradient(ACVA),dc potential gradient(DCVG),etc.These technology are not directed against leakage problem,But through the buried pipeline oil long-term detection work summary,the detection technology which involved Geophysical technology in a certain extent has certain response of buried pipeline leakage signals.Therefore,despite the testing purpose and method of buried pipeline technology,from geophysical technology,in-depth analysis of the specific correlation between it and leakage.It can achieve to screening for leak detection technology and establish the effective code of leak detection.The purpose of the paper is to through the establishment of field leakage simulation experimental area that simulates various oil possible leakage condition,based on a large number of comparative experiments and field application research,combination and optimization of the current commonly used at home and abroad advanced corrosion of buried pipeline detection and leakage detection technology,set up a discriminant method of buried pipeline leakage evaluation and specification.In experimental zone with buried pipes,an investigation using different methods,for example the current gradient?voltage gradient and acoustic emission,has been carried out to recognize the leakage of pipe under various conditions(including media,leakage,location,inspect parameters and devices etc).The technologies of Voltage gradient and acoustic emission could recognize the leakage of pipe on site.The ground penetrating radar(GPR)could define the location of leakage or reduce the region of suspected leakage of the pipe.Through analyzing the properties of leakages of the buried pipes,it should be useful for detecting the location of leakage according to our method provided in this paper.Applied our method,there are one leakage has been located and 23 stealing oil/gas points.Furthermore,the status of corrosion for buried pipes has been estimated.In addition,the experiment of voltage gradient testing show that the changes of transmitting pressure could strongly affect the results of inspections.It could eliminate the effect of disturbing signals if the method of change the pressure has been applied under the electromagnetic interference.The method provides a new idea to detect the leakage of buried pipes.Other inspection technology could apply the method mentioned above to eliminate the interference of electromagnetic signals.