Supplying energy needs
Chile has a dependence on imported natural gas, which supplies a large proportion of their electricity generation. At present, gas imports are predominantly via pipeline from Argentina. However, in 2004 Argentina decided to reduce its gas exports to Chile, forcing a dependence on more expensive fuel oil to make up the difference whilst an increased hydroelectric capacity is developed. In order to reduce this dependence and diversify its gas supply sources, the Government of Chile
decided to build an LNG import terminal at Quintero Bay, about 155 km north west of Santiago. With increasing demand and a growing uncertainty of supply from current sources, there was significant pressure to deliver an operational terminal as quickly as possible.
LNG or liquefied natural gas is natural gas (primarily methane) that has been converted to a liquid form for ease of transport. The gas is chilled to -163ºC and in this state occupies about 1/600th of the volume at close to normal atmospheric pressure and room temperature. It is then loaded into specially designed ships for shipping to the points of gas demand. When the ships arrive at the LNG import terminal the liquid is offloaded and stored in insulated tanks. The liquid is then drawn from the tanks and heated to turn it back into its gaseous form. This process allows countries such as Chile to economically source gas from remote locations around the world.
Beginning in 2006 BG International entered into an agreement with Chilean par tner s (ENAP, Endesa and Metrogas), to form the GNLQ Joint Venture to develop an LNG import terminal. Along with the requirements for future expansion, the Quintero Bay terminal was required to deliver 10 million cubic metres per day of gas by mid
2009. The terminal will ultimately receive around 2.5 million tonnes of LNG per annum, which is equivalent to around 40% of the Chilean gas demand, and have the flexibility for future expansion.
HR Wallingford came onto the project at BG’s request and worked as part of the project team to identify the location of the marine facilities in Quintero Bay, optimise the layout and design of the LNG marine facilities, develop the design of the intake and outfall system to supply seawater for regasification, and to investigate methods for fast-tracking gas supplies.
Defining the challenge
The proposed development infrastructure will comprise:
• Marine facilities for receiving LNG carriers
• LNG storage tanks
• Re-gasification plant using seawater as the heating medium
The initial process was similar to many of the LNG projects in which HR Wallingford have been involved and resulted in the development of a list of primary marine development tasks.
These were defined as:
• Develop a functional requirements specification
• Develop an understanding of the bay environment
• Identify the layout of marine facilities that would best meet the functional requirements
• Develop design concepts, costs and schedule for construction