Decommissioning of deep and ultra-deep water oil and gas pipelines: Issues and challenges

When production facilities reach the end of their economic life in the offshore oil and gas industry, field owners must decide whether to replace, extend the life of, or decommission assets. The decommissioning of deep and ultra-deep water oil and gas pipelines has become a serious issue in recent years because it is a complex process and presents challenges to stakeholders. In this paper, we review the current practices of pipeline decommissioning in different regions of the world and then highlight issues and challenges related to such activities in deep and ultra-deep waters. These issues and challenges can be broadly categorised into technical (e.g., selection of appropriate decommissioning procedures for handling hazardous pipelines), financial or economic, health and safety legislation, environmental, and human or organisational issues (such as lack of requisite skills, knowledge and expertise). In order to address the challenges identified in the study, some directions for future research are suggested.