How Was Oil And Gas Formed?


3 Answers

Simon Davies Profile
Simon Davies answered
Oil and gas a called fossil fuels. They were formed by the sedimentation and fossilization of plants and animals.

When plants near the sea, or tiny sea creatures died, they fell to the bottom of the sea or lake and formed a layer of organic matter. These layers were then covered by layers of sand or other sediment.

As the layers of sediment built up and other changes happened in the crust of the earth, such as volcanic activity or distortion of tectonic plates the organic matter was squeezed and put under pressure and high temperatures.

These high pressures and temperatures changed the organic matter into coal, oil and gas. All three fossil fuels are based on carbon chain molecules called hydrocarbons. Coal contains the largest molecules, oil intermediate length molecules and gas the smallest molecules. Natural gas is mainly made up of methane which is one carbon atom bonded to four hydrogen atoms.
attz malik Profile
attz malik answered
When more and more organic matter starts decaying, it results into the formation of oil and gas formation. That process or condition exists in such environment where there is high production of organic matter such as sea water in bottom, where there is less supply of oxygen in the bottom, in that condition it decompose all organic matter. There condition in some where satisfies in offshore sedimentary basins as well. it rivers, that rate is less because if sedimentation is higher and because of that sedimentation it buried all organic matter and prevent it to decompose. During million years of burial, different chemical and physical reactions, temperature effects at depth result to change some organic material into liquid and different gaseous materials. The hydrocarbons are major source of oil and gas, when the process of compaction of organic sediment into sources beds, it forces the hydrocarbon containing crude oil and fluid pushed into permeable rock for example sandstone that what we called as oil reservoirs. Due to low density of both oil and gas they move easily to the highest place where they start floating above water that is always occupied in the pores spaces of the permeable formations.
Sachin P Profile
Sachin P answered
There are several opinions available on the processes by which oil and gas have been formed. Since long it is believed that these petrochemicals are the changed version of the carbons, gathered in a single place from the huge amount of fossils. Because of some natural calamity, a large quantity of trees, animals, etc. had gone underneath the earth's crust millions of years ago, giving rise to the large number of fossils deposits. Gradually, with the earth's pressure, temperature and chemical reactions those fossils have now converted into the oil and gas. The theory is largely substantiated by the fact that most of the oil and gas deposits have been found either under the sea or near to the sea. But recently the Russian and Ukrainian scientists have proposed an alternate theory on the formation of oil and gas, which also has received wide acceptance.

According to this new theory, fossils are not the creator of oil and gas; rather they have been developed from some inorganic materials. This abyssal, abiotic theory tells that during the formation of the Earth, the available carbon and hydrogen formed into hydrocarbon molecules at the mantle of the earth under the huge temperature and pressure. This theory has able to provide the satisfactory answer for the presence of helium in petroleum.

Scientists have yet not discarded any of the above theories and further research is in progress to find the truth.

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