kms form marine basins of Mesozoic and Tertiary times.India’s offshore areas have Mesozoic and Tertiary rocks of marine origin spread over 2.5 lakh km up to 200 metres,the probability of oil occurrences is rated high in these rocks (divided into 10 basins), particularly the Cambay region where oil was discovered in Bombay High in 1974.
kms form marine basins of Mesozoic and Tertiary times.India’s offshore areas have Mesozoic and Tertiary rocks of marine origin spread over 2.5 lakh km up to 200 metres,the probability of oil occurrences is rated high in these rocks (divided into 10 basins), particularly the Cambay region where oil was discovered in Bombay High in 1974.petrol, paraffin and high grade lubricating oils.(ii) Asphalt-Base Oil: This consists mainly of the heavier hydrocarbons with a viscous, asphaltic base.Tags: Education Past Present Future EssayBusiness Continuity Planning StepsPersuasive Essays By KidsEssay CompanyDo Essays Have ParagraphsGet Someone To Do My AssignmentEssay On Foreign Policy Of Pakistan
Some recent sediment less than one million years also show evidence of incipient oil.
Oil and gas do not occur normally at their original sites.
Thus, oil is usually found in a water-oil-gas sequence, though sometimes only gas is found, and no oil exists.
While petroleum, like coal, can occur in rocks of any geological age from Cambrian to Pliocene, the most productive petroliferous strata in Asia are of Jurassic to Miocene Age.
Much of its residue is in the form of asphalt or bitumen, almost in solid state.(iii) Mixed-Base Oil: This is an intermediate group with mixed properties of the lighter and heavier oils.
It carries a high percentage of naphthene and is graded 20° on the Baume scale. The origin of oil is still not definitely known, though it is generally presumed to be derived from organic material.The word petroleum is derived from the Latin words, Petra meaning rock, and oleum, meaning oil.It is so called because it is derived from the rocks where it flows freely in either liquid or gaseous state.The second belt extends from Mahesana (Gujarat) in the north to the continental shelf offcast Ratnagiri (Maharashtra) in the south and includes the several important oilfields in Gujarat and the Bombay High and other newly discovered oilfields offshore.Againt a 63 per cent supply of primary commercial energy through hydrocarbons in the world in the case of India, it is 44.9 per cent (36% oil and 8.9% natural gas).Wherever there are areas of marine sedimentary rocks such as mudstone, shale, sandstone or limestone oil may be found in some of the strata.The oil is trapped in the pore-spaces of the rocks and thus, rocks such as sandstone with a high proportion of spaces are most likely to contain oil.When the rocks originally formed under the sea, not only oil was trapped but also sea-water. Because oil is lighter than water it usually lies above it in the rock.Above the oil are the lightest hydrocarbons forming natural gas.It is often, therefore, referred to as ‘black gold’.It was first used where seepages occurred at the surface.