Optimization of Offshore Gas Production Systems: The Use of Compact Compression and Separation Unit (CSU) With Isothermal Compression Technology for Reduced Carbon Emissions

Abstract

The main objective of this thesis is to present a novel compression technology as a valid optimization option for offshore gas compression and processing. Several attempts to reduce environmental impact of offshore oil and gas installations while maintain a wide margin on the cost-benefit ratio have been the main driver for research into process systems optimization and energy efficiency in the last two decades. On one hand, offshore gas processing activities are energy intensive and represent a source for significant carbon emissions, mainly because of the rotating machinery involved in these activities. On the other hand, power and heat generating processes stand as one of the major causes of emissions and as such, a balance must be struck between process system optimization and dependence on clean energy systems, to achieve desired results. Hence the introduction of the novel technology – Compact Gas Compression and Separation Unit, CSU. This thesis focuses on a high-level comparison between CSU and current conventional compression systems in use on offshore installations on the Norwegian continental shelf. Further in this study, it will be proven that the CSU is not just an environmentally friendly optimization solution to offshore gas compression, but also a cheaper and more compact option when compared to conventional type compressors. This novel technology is not qualified, but it is beyond the concept stage as at now. Case studies from two of the leading energy companies operating on the Norwegian continental is presented in this study. These cases are not theoretical but practical. They are ongoing projects within the companies and as such, present a perfect opportunity to prove the novel technology concept and qualify the innovative technology through pilot testing and adaptation to the installations. At the end of this study, the numbers will show how CSU compares with conventional centrifugal compressors in cost savings as high as 46% and weight and footprint savings of approximately 35%.