Upstream companies are involved in finding, extracting, and producing raw materials like crude oil and natural gas. Midstream companies link upstream and downstream sectors through storage and transportation. Downstream companies process and refine crude oil into usable products like fuel and gasoline and market these products to retailers and consumers.

1. UPSTREAM AND
DOWNSTREAM
COMPANIES
Ivor R Ellul

2. Introduction
 Holding a Ph.D. in Petroleum Engineering from
Imperial College, London, Ivor R. Ellul maintains a
number of industry affiliations. Based in Houston,
Texas, Ivor Ellul brings years of experience in the
upstream oil and gas industry to his role as managing
director of CiSK Ventures, Ltd.
Companies involved in the oil and gas industry are
often referred to as being either "upstream" or
"downstream." These terms are used to indicate a
company's position in the industry’s supply chain. For
example, companies involved in finding, extracting, or
producing raw materials are said to be upstream
companies.

3. Upstream and Downstream
Companies
 The upstream sector also includes services
related to the industry, such as machinery rental,
rig operations, and chemical supplies.
Midstream operations function as a link between
the up and downstream sectors and typically
include storage and transportation resources.
Refineries and marketing are examples of
downstream operations. Refineries process crude
oil into its usable forms, like fuel oils, gasoline,
and an array of petroleum-based products.
Marketing services then help deliver these
products to retailers and consumers.