Developing Guidelines for On-Stream Mechanical Cleaning of a Complex Pipeline Network

On-stream pipeline cleaning is essential to pipeline operations in terms of maintaining both pipeline efficiency, as well as integrity. Running effective brush cleaning pigs through pipelines will remove accumulated solid debris as well as smoothen the pipe wall. This will reduce pipeline pressure as well as increase product flow. A pig with sealing discs will push out accumulated condensates in gas pipelines and will prevent internal corrosion. The concept is simple, but the implementation is challenging for a complex pipeline network such as the one covered in this paper. The network consists of different types of services both upstream and downstream including oil, gas, and refined products. The pipeline sizes range from 3″ to 56″. The age of pipes vary from 50 years old to new installations and accordingly, their conditions and cleanliness vary. Although pigging is largely based on experience and it is more of an art than a defined science, the complexity of the network needed a systematic approach to develop meaningful and useful guidelines. The approach included conducting gap analysis of current pigging practices in the company, interviews with the senior Operators and subject matter experts, and reviewing the latest literature including manufacturer brochures. The developed guidelines include selection criteria, design, material, as well as measurement effectiveness. The objective of the paper is to present the approach taken to develop the guidelines, as well as to give an overview of the guidelines themselves.