Hydrocarbon Migration

There is a number of observations are collected which shows that oil and gas do not originate generally but they must have migrated into the sedimentary basins . as previously given that organic matter is easily destroyed by oxidization in porous , permeable sediments at the earth surface . oil and gas are trapped in the highest point of a permeable rock unit ,which implies upward and lateral migration .oil, gas and water occur in porous permeable reservoir rock stratified as per as their relative densities value . this stratification implies that they are ,free to migrate vertically and laterally with in the reservoir .