EXTRACTING PETROLEUM - LAB

Crude oil and natural gas are produced in source rocks. Source rocks refer to strata with a large organic component, which later turns to crude oil. Diatomite, a source rock, is a shaly rock that is composed mainly of the remains of diatoms (one celled plants) and radiolarians (protist). As the oil and gas are generated, depending on local conditions, the petroleum products will separate by density.

Oil is less dense than water so it will "float" on water. Gas is less dense than both and will float to the top. Petroleum produced by source rocks will migrate into a "reservoir" rock. A reservoir rock, like sandstone, is a strata that has "space" within the pores of the rock for oil to reside. Reservoir rocks need an impermeable layer above and below so the oil is "trapped."