Abstract
Floating LNG (FLNG) technologies are being deployed to monetize mid-sized offshore gas reservoirs, avoiding constructing a sub-sea gas pipeline to a land based LNG facility and export jetty. A previous OTC-Brasil paper (OTC-26158 Gas Pretreatment Considerations for Floating LNG) has discussed marinization and pre-treatment options available for FLNG, and an OTC paper (OTC-27940 Liquefaction Technologies and Mechanical Drive Considerations for Floating LNG) has discussed space, weight, and safety consideration in liquefaction technology selection. This paper is a continuation, focusing on the thermodynamic and efficiency considerations of the liquefaction technology options. For those not familiar with the previous work, there is some discussion of the marinization and safety drivers within the focus topic.
Offshore liquefaction technologies are often novel and many lack offshore references. The available offshore liquefaction technologies will be presented by Licensor and Technology name. Because of the diversity of liquefaction technologies, and to remain Licensor agnostic, the technologies are grouped by refrigeration method, with Nitrogen expander and SMR (Single Mixed Refrigerant) groupings of technologies examined with an emphasis on overall liquefaction efficiency, efficiency focus areas and design flexibility. DMR (Dual Mixed Refrigerant) is compared with the other two technology groupings.
The paper provides an overview of the FLNG state of the art in liquefaction.
