Black Powder Movement in Gas Pipelines

Abstract

Black powder, a mix of iron sulfides, oxides, and other material can represent a serious threat to the integrity of pipelines by plugging pipelines, damaging customer equipment such as compressors, plugging instrumentation and pipeline drips, and preventing valid in-line inspection by In-Line Inspection (ILI) pigs. However, black powder may not be a problem until it starts to move in the pipeline due to fluid velocity. The velocity to cause movement of dry black powder in pipelines is presented for black powder in gas pipelines. Once black powder starts to move, it will continue to move until the flow rate is reduced or gas is compressed. Examples of black powder problem case histories are presented. Powder in gas pipelines wet with compressor oil or glycol requires higher velocities, and movement of dry black powder can be partially controlled by using corrosion inhibitors.