Single Flowline Tiebacks: Flow Assurance Considerations From Appraisal to Operations

Abstract

In addition to the recent downturn in oil price, as tiebacks get deeper, longer and originate from more remote areas, interest in making single flowline tiebacks (SFTs) viable development options continues to grow. SFTs provide a means for smaller operators with marginal projects and large international operators with stranded assets to move projects from concept to producing assets. The main challenges in making SFTs viable are: Development and implementation of mitigation and remediation strategies for addressing the typical flow assurance challenges encountered in deep-water.Development of operational strategies considering the processing and liquid handling capacities of the existing tieback host. By more clearly understanding the operating conditions from subsurface to surface and systematically addressing each of the field's challenges with novel operating techniques, enhanced facilities and/or chemicals, SFTs have gone from once simply a conceptual idea, to a valid development alternative. The focus of this paper is to apply findings and lessons learned from various SFT projects, ranging from concept selection to decommissioning, to highlight various considerations. It is the hope and intent that by highlighting these considerations we, as an industry, can continue to mature SFTs. This maturation will then be able to provide an alternative development option to make certain projects economically viable, while not making them unfeasible, difficult and unsafe to operate.