Kerogen is an important factor in oil and gas generation and the types of unconventional resources it can form. It consists of four different types, each prone to maturing into a certain form of petroleum product. Type I is predominantly oil-prone, type II can generate both oil and gas, and type II is primarily a gas-generating kerogen. Type IV is considered “dead oil” and does not generate any producible hydrocarbons. The three main producible types can be seen in many different unconventional resources where this report discusses some of the most prominent examples for each type along with the degree of producibility of each formation/resource. Kerogen is an insoluble macromolecular organic matter that forms from various environments, climates, and biota, providing information on the geological past of these kerogen sources. It forms through diagenetic processes in the first few hundred meters of burial (Dow, 1976). Kerogen, when mature, forms oil and natural gas. To become mature, kerogen is converted by increasing temperature and pressure. Kerogen constitutes a large component of the total carbon on Earth with 1016 tons of C compared to 1012 tons of living biomass (Durand, 1980). The original definition of kerogen included only organic matter-rich rocks of economic importance, but this definition was later expanded to include all organic matter rocks capable of generating oil. This is because it has been determined that organic matter in sedimentary rocks, even in small quantities, could generate (mature) oil through pyrolysis or burial over long periods of time. The modern definition from the late 1950s states that kerogen is the dispersed organic matter of sediments insoluble in the usual organic solvents as opposed to extractable organic ones… middle of the paper… Opportunities and Challenges of Oil Shale Development.” GAO (2012): No. p. Web.Pacheco, Kenneth. “Petroleum Potential for the Gothic Shale, Paradox Formation in the Ute Mountain Reservoir, Colorado and New Mexico.” Colorado School of Mines, 2010. Web.Smith, John Ward e Kenneth E. Stanfield. “Petroleum Shales of the Green River Formation in Wyoming.” Associated Geological Guide of Wyoming (1965): n : Springer, 1978. Print.USGS “3 to 4.3 billion barrels of technically recoverable oil estimated in the Bakken formation of North Dakota and Montana: 25 times more. Compared to the 1995 estimate—." USGS Newsroom (2008): n. page. Web. Vandenbroucke, M. and C. Largeau. "Kerogen Origin, Evolution and Structure." Organic Geochemistry 38.5 (2007): 719-833. Print.