Abstract: A method and apparatus for converting natural gas from a remote source into hydrocarbon liquid stable at room temperature, comprising a skid or trailer-mounted portable gas-to-liquids reactor. The reactor includes a preprocessor which desulfurizes and dehydrates the natural gas, a first-stage reactor which transforms the preprocessed natural gas into synthesis gas, and a liquid productions unit using a Fisher-Tropsch or similar polymerization process. The hydrocarbon liquid may be stored in a portable tank for later transportation or further processed on site in a portable hydrocarbon cracking unit to yield fuel or lubricating oils.