Since the events of September 11, 2001, there has been a prevailing attitude of ‘not in my backyard’ associated with any new plans for onshore terminal facilities. At the same time, the US demand for natural gas is increasing.Offshore terminals are among the most interesting solutions to this problem.

Through early project involvement, DNV has helped a number of operators and designers to manage the risks associated with these challenges. DNV has also assisted clients in comparing the risk between onshore and offshore solutions, thus providing risk-based decision-making support.

The main advantages of offshore terminals compared to onshore terminals are flexible locations, less security risk, and less sailing time for trading tankers giving net economic benefits.

An offshore terminal can be built as a gravity-based structure or a floating facility, and can then be located almost anywhere. Based on this, the receiving terminal may be located far from centers of population, thus making any potential impact on the general public less likely.

Located offshore, a gas-receiving terminal constitutes less of a security risk. Such a terminal will also have economic benefits compared to land-based facilities.

The onshore U.S., Western Canada and offshore Gulf of Mexico production of natural gas is diminishing, while the demand for natural gas, especially for gas-fired power plants, is increasing. Based on this, there is a growing interest in safe and secure gas-receiving solutions for North American markets.

In addition to the market concerns related to a potential shortage of gas supply, there is a lot of public and governmental concern regarding the safety and security of large gas-carriers entering ports and the handling and storage of large quantities of natural gas on land, often near urban areas.

Off course, there are challenges associated with offshore terminals too. The process of offloading gas products from gas carriers to the offshore terminal sometimes takes place under demanding environmental conditions. The vessel-collision risk – i.e. passing merchant vessel traffic and visiting gas carriers, supply vessels or tugs – must be managed properly, as must the control of process-related risks in the limited space onboard the offshore terminal.

Offshore gas-receiving terminals are currently under consideration for Australia, West Africa, the US, Japan and the Mediterranean.