Len Krissa, Enbridge Inc., Canada and Christophe Baete, Elsyca nv, Belgium, discuss cathodic protection technology for inspecting damaged coatings on HDD installed pipelines.
The preferred method of new pipeline construction for most major liquid products transmission companies at significant watercourse and roadway crossings is horizontal directional drilling (HDD). Pipelines installed by HDD have an increased likelihood of experiencing coating damage as opposed to those constructed through conventional open trench techniques. Currently available methods for identifying damaged coating regions within pipe installed by HDD cannot always provide absolute or accurate information on the location, size and geometry of the holidays. Lately, coating conductance, CP current requirement test and geotechnical survey data are used as inputs to create a 3D computational model that simulates the polarisation level of HDD coating defects.