A barge, outfitted with gas liquifaction processing equipment and LNG storage tanks, is suggested as a possible way to exploit remote offshore gas production. A similar study with a barge-mounted methanol plant was done several years ago, also using remote offshore feed gas.
This barge-mounted, LNG system, is bow moored to a single point mooring through which feed gas is piped via seafloor pipeline from a nearby gas production facility. The barge is arranged with personnel accommodation forward, LNG storage midships, and gas liquifaction processing equipment aft. A flare boom is cantilevered off the barge's stem.
The basis of design stipulates feed gas properties, area environmental data, gas liquifaction process, LNG storage tank type plus other parameters desirable in a floating process plant. The latter were concerned with safety, low maintenance characteristics, and the fact that the process barge would also serve as an offshore port where LNG export tankers would periodically moor.
The liquifaction process facilities are described, then the product storage and loading facilities. Relief and flare, hot oil circulation, plant and instrument air, inert gas systems, etc. are described under "other process facilities." The barge itself, ballast, lifesaving and safety systems, quarters and shops, plus the single point mooring are outlined in the next section.
A brief summary of results for a barge-mounted methanol plant from an earlier study is then followed by a comparison of LNG and methanol alternatives. The LNG option appears more favourable than the methanol option.