Stranded gas reserve
|This article does not cite any references or sources. (June 2010)|
A stranded gas reserve is found in a natural gas field which has been discovered, but remains unusable for either physical or economic reasons. Gas that is found within an oil well is conventionally regarded as associated gas and has historically been flared. Now gas is circulated back into oil wells to maintain extraction pressure or converted into electricity using gas powered engines.
Economically stranded gas
A reserve of gas can be economically stranded for one of two reasons:
- The reserve may be too remote from a market for natural gas, making construction of pipelines prohibitively expensive.
- The reserve may be in a region where demand for gas is saturated, and the cost of exporting gas beyond this region is excessive. Such reserve is the most likely to be tapped in the future when existing sources begin to deplete.
Physically stranded gas
A gas field that is too deep to drill for, or is beneath an obstruction, may be considered physically stranded. Continuous development of drilling technology provides access to many difficult-to-access fields.
Examples of stranded gas
Alaska has a large reserve of natural gas stranded in its Prudhoe Bay oil field. The largest gas plant in the United States exists there exclusively to reinject the associated gas into the oil fields. Marketing of the gas awaits the completion of the Alaska gas pipeline to carry it to the lower 48 states. Building of the pipeline has been delayed by the availability of low-cost natural gas in Canada and development of non-conventional gas fields in the lower 48 states, as well as political considerations.
Canada has a large amount of stranded gas in its Arctic Islands, Beaufort Sea, and Mackenzie Delta. Marketing of this gas would require completion of the Mackenzie Valley Pipeline to bring it south along the Mackenzie River. Some companies would like to combine it with Alaska gas by building a pipeline offshore in the Arctic Ocean from Alaska to the Mackenzie Delta. The government of Alaska is resisting such option because it would prefer to bring the gas first to southern Alaska, and then transport it across the Yukon along the Alaska Highway. In either case, the pipeline would feed into the continental distribution system in northern Alberta.
Russia, which has the world's largest natural gas reserves, has much of gas stranded in Siberia. In some cases, the easiest way to bring it to market would be by pipelines across the Bering Strait, and then feeding it into the proposed Alaska gas pipeline. Other options include moving it south to China, or west to Europe. Another alternative would be to build liquefied natural gas (LNG) terminals at Siberian ports, where it could be shipped to any port in the world with an LNG regasification terminal.