Propane comes from drilling hydrocarbon wells, usually in some remote area of the country. The wells are classified as crude or natural gas depending on whether they produce heavier hydrocarbons (crude) or lighter hydrocarbons (natural gas). An array of hydrocarbons comes from these wells regardless of type.
Near the fields where heavy hydrocarbon wells are drilled, there are separators. In these separators, water settles to the bottom, heavy hydrocarbons are in the middle, and lighter hydrocarbons rise to the top. Each leaves the separator and heads to the next part of the supply chain. The water is generally disposed of in the field, the lighter hydrocarbons head to a natural gas processing plant, and the heavy hydrocarbons go into tanks or pipelines and ultimately end up at a refinery.