GEOLOGY

Detailed explanation-1: -Thus the Catagenesis phase involves the maturation of the kerogen; petroleum is the first to be released from the kerogen followed by gas, CO2 and H2O. The third phase is referred to as Metagensis. It occurs at very high temperatures and pressures which border on low grade metamorphism.

Detailed explanation-2: -Optimal formation temperatures for maturation and catagenesis range from 90° to 125 °C, reached at burial depths between 2 and 4 km. Greater depth and higher temperature destroy the hydrocarbons. After oil and gas form, propelled by their buoyancy, they migrate from source rocks to porous and permeable reservoir rocks.

Detailed explanation-3: -Catagenesis is a term used in petroleum geology to describe the cracking process which results in the conversion of organic kerogens into hydrocarbons.

Detailed explanation-4: -With increasing temperature the chemical bonds in these large molecules (kerogen) are broken and kerogen is transformed into smaller molecules which make up oil and gas. This requires that the temperature must be 80–150◦C over long geological time (typically 1–100 million years).