Finding Oil

Many people don't know that plastics come from oil. Since this is only the second post of this blog, I thought I'd start at the beginning and do a brief introduction to finding oil. In future posts I'll go into more detail about what happens to oil after its discovery and the process of how it becomes plastic.

Imagine large stagnant pools of water covered with algae growth. Without sunlight and aeration, life-cycles in these pools were very short. As the the millions of microorganisms died and piled up on the bottom, layer upon layer, pressure continued to build. This pressure, aided by volcanic activity and millions of years eventually removed all water molecules out of the layers. The heat and pressure finally broke down these layers until they become oil. The oil then rises up through the porous rock layers until it becomes trapped by non-porous layers above. Oil then pools in these areas until it is discovered by the oil companies.

Eureka!
Oil companies spend millions of dollars to find and extract oil because oil fields are rich finds not only of oil but also natural gasses. Oil fields can be found both on land and under the ocean floor. Typically oil reservoirs contain three main resources, namely water, natural gas, and oil.

Water
Water is commonly found along with natural gas and oil. This water is of little value and for the most part is ignored. When the drilling is finished and the well capped off, the water remains.

Natural Gas
Above the oil are large quantities of natural gas. The gas is brought to the surface, gathered from individual wells and then sent to processing plants. Processed natural gas consists almost entirely of methane; however, natural gas in its unprocessed state consists of methane; NGLs such as ethane, propane and butane; pentanes, water, hydrogen sulphide and other gases such as carbon dioxide and nitrogen. Most of these components are removed from the natural gas either at processing facilities at the gas field or at straddle plants located on pipeline systems. The hydrogen sulphide is extracted in the form of elemental sulphur and is used in the manufacture of fertilizers and other products. The NGLs are sold separately for use as diluent in heavy oil processing, as feedstock for petrochemical plants or as fuel.

Oil
Crude oil is naturally occurring petroleum.  Organic compounds consisting only of carbon and hydrogen are called Hydrocarbons.  Petroleum is the general term for solid, liquid or gaseous hydrocarbons.   These hydrocarbons are the basis of oil, natural gas and coal.

Lots more great information can be found at Centre for Energy and at How Stuff Works.
Photo by by Mike Woodfin.