The exploration of gas fields in more remote and / or deeper water environments will continue to increase over the coming years. The economic viability of these fields needs to be demonstrated or else they will be left stranded. Gas field developments entail numerous multifaceted issues related to the transported fluid such as: pressure drop, liquid hold-up, hydrates, corrosion and sand. The recent subsea technology development, Pseudo Dry Gas System (PDGS), has demonstrated that deep water fields (~2000 m) can be transported long distances (~200 km) to existing processing facilities [Ref. 1]. The objective of this paper is to compare the available subsea processing options, based on recoverable reserves, extent of plateau production and the economic performance. The paper will examine emerging subsea processing arrangements from subsea dry and wet gas compression to PDGS whilst highlighting the impact of a conventional subsea tieback. The paper examines the work previously performed in the DEPTH study [Ref. 2] in selecting the subsea processing options whilst using the current processing performance as constraints in the modelling. A set of key parameters that impact the amount of recoverable reserves will be assessed; these include: tie-back distance, water depth, water production and reservoir size. The use of a life of field integrated modelling approach using the latest multiphase correlations with the in-built subsea processing equipment is linked with economic models to evaluate the long-distance gas development options and chose the best techno-economic subsea processing technology. The paper will demonstrate the subsea processing operating envelopes for all the variations examined, water depth, tieback distance, water production and reservoir size and highlight the arrangements which maximise the recoverable reserves, increase the plateau production and provides the best economic performance of all the subsea processing technologies examined.

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