Pipeline maintenance works:
The main measures to maintain and restore the normal operation of transportation pipelines and their equipment, including regular and temporary pipeline maintenance and repair.
Remove oil, condensate, wax, mechanical impurities, and corrosion products such as iron sulfide and accumulated water in the gas pipe to restore or improve the efficiency of pipeline transportation. These substances are attached to the pipe wall or deposited under the pipe, which reduces the cross-sectional area of the pipe and corrodes the inner surface of the pipe, increasing the energy consumption of oil and gas transportation. Pigs are mainly used for pigging. Various instruments are installed on some pigs to measure pipe wall thickness, internal corrosion, pipe deformation and position settlement. Common pigs are spherical pigs, leather pigs and soft pigs.
Pipeline maintenance work highlights large-scale accident handling operations such as leak repair and pipe replacement. If the leak is caused by corrosive perforation, you can use a clamp to plug the leak in the pipe and then perform repair welding. If the pipe is severely damaged or deformed, the pipe must be cut and replaced with a new pipe section. Oil or gas leaking from the pipe can easily cause a fire. When cutting pipelines at a low place, a large amount of oil and gas must be prevented from leaking out. Mechanical occluders are often used to block pipelines, and repair operations are carried out without stopping.
The method of mechanical plugging is to open a hole in the upstream and downstream of the pipe section to be replaced. Each hole is plugged with a plug with a leather bowl to cut off the oil or gas at both ends, and then drain the oil in the damaged pipe section. Or gas, use a mechanical cutter to cut the pipe section, and then insert two pigging balls into the cutouts at both ends, and fill nitrogen between the pigging ball and the plug to prevent explosion during welding. Put the new pipe section in place, match it, and weld it. After the welding is completed, the plugging device is lifted out of the pipe and the opening is closed to complete the plugging and replacement work. When the pipeline was repaired and operated, two pigs were recovered in the pig receiver of the downstream station. When plugging and replacing pipe sections, bypass pipes can be drawn out before plugging to ensure uninterrupted pipeline transportation during the entire pipe changing process