There are many reasons for pipeline leakage, which can be mainly divided into three categories: corrosion perforation, fatigue rupture, and external force damage.
Although taking corrosion control measures can significantly slow corrosion, it does not prevent corrosion. When the cathodic protection is insufficient, the pipeline corrosion process will be slow but will not stop due to the cathodic protection; when the cathodic protection is shielded, the pipeline corrosion will not be inhibited at all. Insufficient cathodic protection means that the protection currently provided by the cathodic protection system cannot meet the pipeline protection requirements; cathodic protection shielding means that the cathodic protection current is blocked in the flow and cannot reach the predetermined position. When there is a large area of damage, continuous leakage points, or a decline in the overall insulation performance on the coating, it is easy to lead to insufficient cathodic protection. Since such defects can be found through testing, corrosion accidents can generally be avoided by repairing them. When the coating is peeled off from the metal of the pipe body, it has a shielding effect on the cathodic protection system, especially the coating made of organic synthetic materials with high insulating properties, but the existing detection technology is difficult to detect the peeling off of the coating, so it is easy to produce Corrosion perforation leaks.
Oil and gas pipelines operate under high-pressure conditions for a long time, the mechanical properties of the pipeline metal will gradually decay, and the micro-cracks existing in the pipeline weld itself and due to stress corrosion will expand, and the cracks develop to a certain extent. Rupture accident, resulting in leakage. For gas pipelines, ruptures can have catastrophic consequences.
External damage mainly includes natural disasters and man-made disasters. Floods, landslides, mudslides, earthquakes, etc. may damage the pipeline; man-made disasters mainly refer to third-party damage, including unintentional damage caused by the construction of various construction projects such as road construction, excavation, etc., drilling, and stealing oil and gas Deliberate sabotage caused by criminals, etc., has now become a major threat to pipeline protection, and in some areas, it is even a bit of a cause of sabotage.
For large and sudden pipeline leakage accidents such as pipe bursting, rupture, etc., due to the sudden loss of pressure in the pipeline, they can generally be found in time, but an on-site inspection is required to determine the specific location. For small leaks, leak detection techniques are required. Leak detection technology includes offline detection and online monitoring.
Off-line inspection is an inspection along the pipeline as required or on demand. It can be inspected on foot, inspected by car, or taken on a special plane for flight inspection. Find leaks by looking at the surface, instrument detection, or infrared imaging techniques. Because detection is not always performed, this method generally fails to detect leaks in time after they have occurred.
Online monitoring is to use the leakage monitoring system specially installed on the pipeline to dynamically monitor the pipeline, capture the leakage information at the moment of leakage, issue an alarm, and quickly calculate the leakage location through the computer.
Pipeline leakage Oil and gas pipeline leakage not only causes oil and gas loss, but also pollutes the environment, and may even cause fire, explosion, and other accidents. Therefore, it is very important to ensure the safe operation of pipelines.
Post time: Sep-06-2022