Gas processing plants are usually located fairly close to the source of supply. 
They come in a variety of shapes and sizes from small movable units to straddle plants to large extraction units that deal with sour gas. Read more
Once the gas has been processed, it becomes known as "sales gas".
Sour gas: Raw natural gas with a concentration of hydrogen sulphide (H2S) greater than 1%.
In 2010, processing and production consumed 12,543,450 GJ and emitted 1,845,590 GHG tonnes.