Kerogen is an important factor in the production of oil and gas and the types of unconventional resources it can form. There are four different types, each capable of becoming some form of petroleum product. Type I is primarily oil-prone, Type II can produce both oil and gas, and Type II is primarily 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 in which this report discusses some of the most important examples for each type as well as the producibility of each formation/resource. Kerogen is an insoluble macromolecular organic matter that forms from various environments, climates and biota, providing insight into the geological past of these kerogen sources. It is formed by diagenetic processes during the first few hundred meters of burial (Dow, 1976). Kerogen, once mature, forms oil and natural gas. To become mature, kerogen is converted by increasing temperature and pressure. Kerogen represents a significant part of the total carbon on Earth with 1,016 tonnes of C compared to 1,012 tonnes of living biomass (Durand, 1980). The original definition of kerogen included only organic-rich rocks of economic importance, but this definition was later expanded to include all organic-rich rocks capable of generating petroleum. Indeed, it has been determined that organic matter present in sedimentary rocks, even in small quantities, can generate (mature) oil through pyrolysis or burial for long periods of time. The modern definition from the late 1950s states that kerogen is dispersed organic matter. of sediments insoluble in usual organic solvents as opposed to extractable organic solvents...... middle of paper...... Opportunities and challenges of oil shale development. " GAO (2012): n. pag. Web.Pacheco, Kenneth. “Oil potential of the Gothic Shale, Paradox Formation in the Ute Mountain Ute Reservation, Colorado and New Mexico”. Colorado School of Mines, 2010. Web.Smith , John Ward and Kenneth E. Stanfield. "Bitumen Shales of the Green River Formation of Wyoming." Associated Geological Guide to Wyoming (1965): Web. Tissot, BP, and DH Welte. of Oil and Gas Exploration: Springer, 1978. Print.USGS "3 to 4.3 billion barrels of technically recoverable oil assessed in the Bakken formation of North Dakota and Montana: 25 times more. Estimate higher than 1995—." USGS Newsroom (2008): n. pag. Web. Vandenbroucke, M. and C. Largeau. “Origin, evolution and structure of kerogen.” Organic Geochemistry 38.5 (2007): 719-833. Print.