Evaluation of the Application Effect and Improvement Method of Corrosion Monitoring Technology for Buried Thermal Insulation Pipelines

Abstract

In order to further clarify the cathodic protection effect of buried thermal insulation pipeline，improve the cathodic protection monitoring technology，reduce oilfield maintenance costs and ensure the safe operation of buried insulation pipeline in oilfield，the detection and monitoring tests of a buried thermal insulation delivery pipeline were conducted，the field application effect of the detection and monitoring technology for buried thermal insulation delivery pipelines in oil fields at present was analyzed，and a stable and inexpensive external corrosion monitoring device was proposed for pipelines inside the insulation layer.Results showed that the accuracy of the test results of outer anti-corrosive coating would be affected by the protective layer，when using PCM，ACVG and DCVG technologies.Using a high-definition magnetic flux leakage detector to detect the corrosion status of pipelines，the detection result error was 6%，but the detection results could not distinguish whether there was metal loss on the inner or outer walls，and the excavation verification was required.Due to the current shielding effect of anti-corrosive insulation layer，the measurement value of cathodic protection potential could not characterize the true potential of the pipeline.The designed external corrosion monitoring device for buried thermal insulation pipelines based on metal potential difference could effectively monitor the water ingress of insulation layers of buried thermal insulation pipeline and the cathodic protection potential of pipelines for a long time.

Keywords

• buried thermal insulation pipeline|anti-corrosive layer detection|corrosion state detection|cathodic protection potential monitoring|external corrosion monitoring equipment