Investigation of Heavy Sludge Formation in a Chemically Inhibited Sour Gas Pipeline: How Far Do We Have to Go?

In this paper a summary of the investigation performed to identify the root causes for the heavy sludge formation in a sour gas pipeline downstream of a gas process plant is provided. The investigation included reviews of historical and current gas and heavy hydrocarbon analyses, particle size analysis, field investigations, operational records, records of cleaning pig runs, and analysis of chemicals used in the upstream process plant and in the pipeline. The strategy undertaken by the operator to manage and mitigate the issue of heavy sludge formation based on the investigation results is also discussed. In the first phase of the investigation, the operational conditions which resulted in sludge formation were investigated but the detailed chemical analysis to determine the mechanism of sludge formation will be performed in the next phase of the investigation, and therefore is not included in this paper.