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Exxon develops new LNG storage tank Company says modular storage system can save months in construction Larry Persily Petroleum News Government Affairs Editor
ExxonMobil believes its new modular system for liquefied natural gas storage tanks could trim up to a year from construction schedules.
The key to the patented construction system is a rectangular, self-standing storage tank of nickel (9 percent) and steel, “standardized, scalable and pre-engineered for a broad range of design conditions,” according to a statement from ExxonMobil Upstream Research Co.
“The technology employs modern shipyard fabrication practices,” the company said. “It is modular because of a repeated structural module between the two tank ends that permits a variable length and thus the variable capacity of the tank.”
The research company recently licensed the patented technology to U.K.-based Skanska Whessoe, which operates worldwide to design and build LNG storage tanks and terminals.
“(The) design allows it to be constructed off-site, in parallel to the on-site construction of the reinforced, pre-stressed concrete outer tank,” the ExxonMobil statement reported. Both the inner nickel-steel tank and the outer concrete tank are independently capable of containing the stored LNG. Tanks could hold 200,000 cubic meters of LNG Contractors could build one of the modular tanks to hold as much as 200,000 cubic meters of LNG, with the company reporting that a standardized version of its storage system to hold 100,000 cubic meters would measure 44 feet wide by 33 feet high by 100 feet long.
The first use of the new technology could come at an LNG receiving terminal ExxonMobil plans for offshore in Italy’s northern Adriatic Sea, near Venice.
The terminal, scheduled to open as soon as 2007 to regasify and send out about 800 million cubic feet of gas a day, is a partnership of ExxonMobil (45 percent), Italy’s Edison (10 percent) and Qatar Petroleum (45 percent), which will supply most of the natural gas for the facility 10 miles off the Italian coast in 95 feet of water. Exxon/Qatar in LNG partnership ExxonMobil said the new storage tanks are among the technological advancements under way for its joint venture projects with Qatar Petroleum, including plans for the world’s largest liquefaction trains that would each produce more than 1 billion cubic feet of gas per day from the Middle East nation’s giant North field.
Development of the modular tank construction technology started in 1997 at Mobil, and continued after Exxon took over its smaller rival.
“Storage system construction is often on critical path for an LNG receiving terminal,” Exxon said. “Parallel construction of the inner and outer tanks can reduce construction time by up to 12 months, with associated cost savings,” as opposed to building the two tank structures in succession at the job site.
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