Upstream, Midstream, Downstream.
What are the differences? In the oil and gas industry, there are various sectors which may be conveniently be described as upstream, midstream, and downstream. "Upstream" refers to the exploration and production of oil. "Midstream" refers to the transporting, processing, and storing of oil. "Downstream" refers to the manufacturing, refining, petro-chemicals, marketing, and retailing of oil. This is how the upstream river looks like.