Natural Gas

Natural gas is mostly formed from plankton—tiny water-dwelling organisms, including algae and protozoans—that accumulated on the ocean floor as they died. These organisms were slowly buried and compressed under layers of sediment. Over long periods of time, the pressure and heat generated by overlying sediments converted this organic material into natural gas. Natural gas frequently migrates through porous and fractured reservoir rock with petroleum and subsequently accumulates in underground reservoirs. Because natural gas and petroleum are formed by similar natural processes, these two hydrocarbons are often found together in underground reservoirs