What are the causes and detection methods of oil and gas pipeline leakage

There are many reasons for the leakage of oil and gas pipelines, 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 corrosion process of oil and gas pipelines will be slow but will not stop due to cathodic protection; when the cathodic protection is shielded, the corrosion of oil and gas pipelines will not be inhibited at all. Insufficient cathodic protection means that the protections currently provided by the cathodic protection system cannot meet the protection requirements of oil and gas pipelines; 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 cause 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 oil and gas pipeline metals will gradually decay, and the micro-cracks existing in the oil and gas pipeline weld itself and due to stress corrosion will expand, and the cracks will develop to a certain extent. The oil and gas pipeline rupture accident resulted 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 oil and gas pipelines; 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. Deliberate damage caused by lawbreakers such as gas has become a major threat to the protection of oil and gas pipelines.

For large and sudden oil and gas pipeline leakage accidents such as pipe bursts, fractures, etc., due to the sudden loss of pressure in the oil and gas pipelines, 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.

Offline inspections are inspections along oil and gas pipelines that are scheduled or required and can be inspected on foot, by car, or by flight inspections by special planes. 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 oil and gas pipeline to dynamically monitor the oil and gas 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 oil and gas pipelines.