Crude Oil
Crude Oil
Petroleum also known as crude oil, naturally occurring oily is a bituminous liquid composed of organic chemicals. Petroleum means rock oil, from the Greek petros (rock) and oleum (oil).
It occurs in the earth in liquid, gaseous or solid forms. The term is usually restricted to the liquid form, commonly called crude oil but as a technical term it also includes natural gas and the viscous or solid form known as bitumen. Petroleum is a complex mixture of organic liquids consisting of hydrocarbons (compounds composed mainly of hydrogen and carbon with some nitrogen, sulphur and oxygen).
Petroleum is formed under the earth’s surface by the decomposition of marine organisms. The remains of tiny organisms that live in the sea, that are carried down to the sea in rivers and of plants that grow on the ocean bottom are enmeshed with the fine sands and silts and settle to the bottom in quiet sea basins. Such deposits that are rich in organic materials become the source rocks for the generation of crude oil. The process began millions of years ago and still goes on today. Trapped in fine-grained sediments, the remains are cooked by the heat of the earth to produce oil and gas. Once the petroleum forms, it flows upwards in the earth’s crust because it has a lower density than the constituents of the earth’s crust. When petroleum is trapped, a reservoir of petroleum is formed.
Exploration is probably one of the most important steps of producing oil. In order to find oil underground geologists, geophysicists and exploration engineers attempt to search for it so that petroleum-producing companies can drill for it. They must search for a sedimentary basin in which shales rich in organic material have been buried for a sufficient long time for petroleum to form. The petroleum must also have had an opportunity to migrate into porous traps that are capable of holding large amounts of fluid. The occurrence of crude oil in the earth’s crust is limited both by these conditions, which must be met simultaneously, and by the time of span of tens of millions to a hundred millions years required for the oil’s formation. These people have many tools at their disposal such as Jack Ups, Semi-submersibles and Drill ships to assist in identifying potential areas for drilling. Exploration mostly involves luck, with one out of ten drilling becoming commercial successes.
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