Gas to liquis or GTL is a refinery process to convert natural gas or other gaseous hydrocarbons into longer-chain hydrocarbons. Methane-rich gases are converted into liquid fuels either via direct conversion or via syngas as an intermediate, for example using the Fischer Tropsch or Mobil process. Using such processes, refineries can convert some of their gaseous waste products into valuable fuel oils, which can be sold as or blended only with Diesel fuel. The process may also be used for the economic extraction of gas deposits in locations where it is not economical to build a pipeline. This process will be increasingly significant as crude oil resources are depleted, while natural gas supplies are projected to last into the 22nd century.