This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 30871, “Could Barge LNG Replace FLNG?” by Edward A. Hernandez, Timothy D. Highfield, and Thomas G. Forbes, io consulting, et al. The paper has not been peer reviewed. Copyright 2020 Offshore Technology Conference. Reproduced by permission.
Most currently operating floating liquefied natural gas (FLNG) vessels are ship-shaped and designed for offshore, over-field locations. This approach, however, does not necessarily offer an optimized solution for gas monetization. An alternative solution is barge-based LNG (BLNG), focused on near-shore positioning with liquefaction facilities mounted on a simple floating or grounded substructure with the remainder of the systems decoupled from the liquefaction technology in a separate location. The complete paper addresses the benefits of BLNG and why it is an increasingly viable gas-monetization concept.
BLNG is focused on near-shore or at-shore positioning. The LNG liquefaction facilities are mounted on a simple floating substructure and either moored near shore, connected to shore by a jetty, or set down in a prepared dry dock. The remainder of the system (preprocessing, liquids handling, and storage) is decoupled from the liquefaction technology and can be in separate locations. Examples include an FPSO in deep water over the field; adjacent to onshore gas wells; or, as technology develops in subsea processing and compression, feeding the BLNG facility.
BLNG concepts typically consist of multiple LNG trains that meet the required throughput. BLNG minimizes project risk by better aligning the phasing of the development with the proving-up of the reservoirs. The approach also could help deliver greater certainty through better control over the scope of supply and fabrication away from remote, low-infrastructure locations.
The authors do not advocate BLNG as a replacement for FLNG in all cases, nor are they critical of current and future FLNG developments. They write that FLNG and BLNG each have their place and that it is important for owners, consultants, and contractors to appreciate the strengths and weaknesses of each so that quality decisions can be reached.