How was petroleum formed?
It is believed that millions of years ago, the microscopic plants and animals which live in seas died. Their bodies sank to the bottom of the sea and were soon covered with layers of sand and clay. Over a period of millions of years, these remains, in the absence of air, got converted into petroleum under the combined effect of high temperature, high pressure and bacteria. The petroleum so formed passed through porous rocks until it got trapped between some impervious rocks. Natural gas always occurs under the petroleum under the earth.
How was natural gas formed?
Natural gas is formed under the earth by the decomposition of vegetable matter lying under water in conditions of high temperature, high pressure and in the absence of oxygen.
