The goal of this project are to further develop, test, and demonstrate the impressed alternating cycle current (IACC) monitoring method for detecting third-party contact with pipelines in real time. This method will allow existing pipelines to be retrofitted for monitoring without excavation through the use of existing cathodic protection (CP) test points.
Southwest Research Institute (SwRI) – project management and research product
San Antonio City Public Service (CPS) – pipeline donation
San Antonio, Texas 78238
Third-party contact with pipelines (typically contact by a digging or drilling device) can result in mechanical damage to the pipe. Because this type of damage often goes unreported but can lead to eventual catastrophic failure of the pipe, a reliable, cost-effective method is needed for monitoring and recording third-party contact events. Since over half of subsurface damage results from third-party infringement, a capability for detecting contact and locating encroachment would be greatly beneficial.
Several methods exist, or are being investigated, for monitoring and reporting third-party contact or activity near a pipeline. These include: acoustic monitoring devices, continuous fiber-optic sensors buried alongside the pipe, satellite surveillance, cathodic protection monitoring, and methods that rely on the third party to alert the pipeline owner prior to digging. Because all of these methods have inherent limitations under certain conditions, the current project was initiated to investigate an alternate monitoring method. This method, impressed alternating cycle current, is capable of directly and continuously monitoring pipelines for third-party contact. Implementation of this method is relatively straightforward, and it can be retrofitted to existing pipelines without the need for excavation.
This project will further develop the IACC method to improve detection range and to reduce potential interference from extraneous noise sources, including those from CP systems. This will be accomplished through the refinement of IACC signal excitation and processing parameters. Any potential effect of the IACC approach on the proper functioning of CP systems will also be determined, and mitigation methods will be developed if necessary. Testing and demonstration of IACC will be performed through the use of a buried test pipe at the Southwest Research Institute (SwRI), as well as operating gas pipelines, and will include the effects of variability in soil types and conditions. Based on the results of the tests, system operating parameters and capabilities will be analyzed, and a design specification for an IACC system will be developed for use by a commercializing vendor.
Final tests with the newly developed signal processing approach will be conducted at several locations on an existing gas pipeline operated by City Public Service (CPS) of San Antonio or another pipeline operator. The tests will allow a determination of the maximum distance that can be obtained between monitoring stations. Tests will be conducted at different locations to determine the effect of different soil types and typical background noise that must be dealt with by the IACC. Periodic tests will be conducted to determine the influence of different soil moisture conditions. The test results will be evaluated to determine IACC operating capabilities over a wide range of soil types and moisture conditions. Based on the results, guidelines and specifications will be developed for design and operation of a field ready system.
The IACC method is a promising new method for monitoring third-party contact of pipelines. This method will allow existing pipelines to be retrofitted for monitoring without excavation through the use of existing cathodic protection (CP) test points. The method could be readily applied to new pipelines as well. Upon completion of the work, guidelines will be developed for use by a vendor/developer to begin development of a commercial version of an IACC system.
All experimental work has been completed.