All LNG import operations require berthing or docking facilities, offloading capability, storage tanks, regasification equipment and sendout lines. Four different offshore concepts mix and match these facilities in novel and creative ways.

A gravity-based structure (GBS) is a massive rectangular, prismatic caisson that rests on the ocean floor. LNG tankers would dock alongside or in tandem and offload into a tank in the caisson’s interior. Regas equipment on the structure would feed the product to a submarine pipeline tied into the onshore gas network. "The GBS is an attempt to deploy onshore technology in an offshore environment," says Max H. Krekel, senior naval architect at Bluewater Offshore Production Systems (USA) Inc., Houston.

A fixed platform cannot incorporate storage into the structure, so the LNG must be regasified during offloading. A floating storage and regas unit (FSRU) is a permanently anchored vessel that regasifies LNG stored onboard and sends it out via subsea pipeline.

The Energy Bridge concept uses purpose-built LNG tankers that regasify onboard and send the gas out via a permanently moored docking buoy that floats below the surface.