Natural Gas is classified as coming from either “conventional” wells or “unconventional” wells. Conventional wells are relatively shallow and gas is easier to extract than from unconventional sources. Unconventional sources include “tight gas”-gas extracted from tight geological formations such as sandstone or limestone, as well as shale gas.
At this time Coal Bed Methane is the primary source of natural gas production in southwest Virginia while Shale Gas is the primary source of natural gas production in eastern Kentucky.