Development Options for North American LNG Export: The Merits of Inshore Deployed FLNG for Liquefaction of Onshore Shale Gas and Examination of Principal Technology Drivers

摘要

The advent of shale gas onshore United States and Canada, the resulting overhang of gas supplies and downward pressure ongas prices have led Operators both upstream and midstream to consider the possibilities of LNG liquefaction plants for theexport of LNG from coastal locations to international markets. Several proposals for onshore liquefaction submitted to DoEand FERC, e.g. by Cheniere Energy relate to the conversion of existing under-utilized LNG regasification sites. Thedevelopment of LNG liquefaction at any greenfield onshore site is, however, anticipated to come under rigorous ‘permitting’scrutiny. From this standpoint, LNG FPSO provides an attractive development option for the monetization and export of shalegas, a growing feature of interstate and intrastate pipeline networks.The paper assesses the technology implications of migrating LNG FPSO concepts hitherto developed internationally to thisinshore service. The LNG FPSO topsides processing, including feed pre-treatment and liquefaction systems are evaluated forthe processing of feed gas sourced from either pipeline grids or from onshore gas plants with partial or full stripping of NGLs.The technology options for LNG storage, product offloading, and hull forms are also assessed for simplification that resultsfrom inshore deployment. The authors draw on insights from a recent FEED execution for a floating liquefaction unit destinedfor an inshore Asia Pacific location, and other FLNG studies to analyze the merits of inshore deployments in the NorthAmerican context.While schedule and project cost are conjecturally viewed as potential benefits, the paper addresses the following:Does feed gas partially or fully conditioned onshore, materially alter the processing required on the FPSO, e.g. in acid gasremoval, dehydration, and NGL extraction?What are the implications for choice of LNG liquefaction cycles, train capacity, and for refrigeration compression power, as aresult of processing conditioned gas?Do atshore/inshore deployments widen the choice of technology options for LNG containment and for LNG offloading?What are the potential hull forms that may be considered candidates for these applications?The paper critically assesses the above issues and choices in formulating a technology roadmap for LNG FPSO developmentsfor North American onshore gas.