This statement is true but also rather misleading. It is misleading in the sense that on a global scale most conventional oil and gas is reservoired in carbonates (~60%) and sandstones (~40%). Only a very small percentage is reservoired in igneous or metamorphic rocks. Shale oil and shale gas are reservoired in shale (= claystone)

Oil and gas often to be in anticlinal zone. But if we see thinking about migration that oil reservuare will be if there have sandstones