Offshore Processing Options for Oil Platforms

Abstract

Abstract An examination of the various processing options that have been implemented on previous (and recent) offshore oil field developments indicates a very broad range of possibilities. The spectrum ranges from: Minimal offshore processing with all produced fluids sent to an onshore terminal (or terminals) for final processing to meet saleable product specifications, to Full processing offshore to make specification products on the offshore facility, with no further onshore processing required. The decision as to where a given project ultimately ends up on this spectrum can have significant implications. For example: – is the offshore platform small and simple or large and complex? – is an onshore terminal (or terminals) required for final processing or not? – does the gas export pipeline operate in multiphase, moderate pressure single phase, or high pressure dense phase? – what is the impact on project schedule and manning requirement? eg. offshore platform size and complexity, number of facilities - offshore only or both offshore and onshore? – what is the impact on subsequent future projects? There is little published information or guidelines as to how to make the onshore/offshore processing split decision. Often it is fairly obvious based on the proximity to existing infrastructure (developed areas). In other cases, eg. new offshore regions with minimal infrastructure, it is not. In this regard, the various major offshore producing areas around the world, eg. the Gulf of Mexico (GoM), North Sea, etc., have often taken different approaches. Even in these established regions, there are significant variations in processing scheme details, from facility to facility and between operating companies. In order to begin to address the "optimum" offshore/onshore processing split issue, it is necessary to first gain an understanding of what the options actually are. The purpose of this paper is to review the main processing options available for an offshore oil production facility, including comparisons, major factors, pro's and con's, etc. This information can serve as a basis for evaluating processing alternatives for future projects. The Gulf of Mexico and North Sea are large, well established offshore production arenas. They can be used to provide historical context and act as points of reference. The concepts discussed are applicable to all offshore production regions.