The use of differential GPS as an inspection tool in the external corrosion control of buried pipelines
- Asesoria Adiestramiento y Construccion, Caracas (Venezuela)
A maintenance program was designed to improve the cathodic protection level of two oil gathering pipelines of an oil production facility in Eastern Venezuela. The program was built upon the information obtained from a coating condition evaluation and the soil resistivity profile along the pipeline corridors. The external coating was inspected with the Direct Current Voltage Gradient technique, DCVG; the soil resistivity of the pipeline corridor was measured every 100 meters (328 ft.). All the geographical information was obtained with Differential Global Positioning System (DGPS). This allowed the pipeline operator to relocate all coating defects with a sub metric accuracy that considerably reduced the rehabilitation costs. The coating inspection covered a total distance of twelve thousand, nine hundred and thirty-six meters (12,936 meters). Two hundred and ninety two (292) defects were found; 54 defects belonged to Category 3 and will need immediate repair. The soil corrosiveness along the pipeline corridors was established by the resistivity gradient. Critical areas were established and exploratory digs were recommended to assess exposed metal condition.
- OSTI ID:
- 350146
- Report Number(s):
- CONF-980316--
- Country of Publication:
- United States
- Language:
- English
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