(302c) Methodology for the Selection of Small Scale LNG Technologies for Remote Gas Production

Natural gas fields accessible via proven technology are limited demanding that smaller and less accessible gas field should be considered for commercial exploitation. The Liquefied Natural Gas (LNG) could be a solution for this kind of gas reserves, but in the case of remote gas fields with a low productivity, the large scale LNG technologies are neither practical nor economical. The small and middle offshore scale technologies demand different requirements than the ones related to conventional on-land LNG plants. While a thermodynamic efficient process is considered a most important parameter for the selection of onshore LNG plants, other factors need to be considered in the process selection for offshore LNG plants such as safety, compactness, low equipment count, modularization, easy maintenance, reliability, simple operation, low influence of the motion of the vessel, etc. Offshore LNG plants require overcoming many challenges due to the marine environment (winds, currents and waves). The motion of the vessel can affect the process efficiency. In addition, the limited space demands highly compact and light processes. In general, the main characteristics of the Mixed Refrigerant and Expander technologies made them suitable for developing an offshore LNG project, but which is the most convenient choice might depend on the particular scenario. The most important aspect in this work is that the costs related to the offshore installation are included as a component of the capital cost of LNG project. The plot area required for each technology plays a significant role in the final comparison and this parameter should not be neglected in the economical analysis of future offshore LNG plants.