Integral evaluation of the external corrosion control system for buried pipelines
- Asesoria Adiestramiento y Construccion, Caracas (Venezuela)
The External Corrosion Control System of a 16 inch diameter (406 mm), 70 miles long (113 km) pipeline, was evaluated using the Direct Current Voltage Gradient DCVG, Close Interval Potential Survey CIPS and Continuous Soil Resistivity Evaluation CSRE techniques. Sixteen thousand five hundred meters (16,500 meters) of the pipeline were evaluated using the three techniques simultaneously and the rest was inspected separately in previous years. The results from the survey were taken as parameters to classify all defects found on the protective coating. A Defect Severity Classification (DSC) was established and used as an input for a maintenance program for the rehabilitation of the pipeline integrity. The parameters taken to establish the DSC were: (a) Instant Off Potential, (b) %IR, (c) Soil Resistivity, (d) defect shape, (e) Geographic location, (f) Distance from drain point. A Maintenance Program for the Pipeline External Corrosion Control System was designed by implementing the Integral Evaluation of the Corrosion Control System for Buried Pipelines (IEECCSBP). The priority was to achieve pipeline integrity and then, gradually improve the protection level of the system. The implementation of IEECCSBP will help to reduce the frequency of Electromagnetic Metal Loss Inspections, which in the future will serve only as an audit of the External Corrosion Control System performance.
- OSTI ID:
- 350147
- Report Number(s):
- CONF-980316--
- Country of Publication:
- United States
- Language:
- English
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