Overview

Oil is found together with gaseous hydrocarbons at depths of tens of meters to 5-6 km. However, at depths greater than 4.5-5 km dominated by gas and gas condensate reservoirs with a minor amount of light fractions. The maximum number of oil deposits located at a depth of 1-3 km. At shallow depths and natural outcrops on surface oil is converted into a thick Malta, semisolid asphalt and other education - such as tar sands and bitumen.

Chemical composition and origin of oil is close to natural gas fuel, ozokerite and asphalt. These resources are collectively called petrolytes. Petrolytes referred to even larger group of so-called caustobioliths - combustible biogenic minerals, which also includes solid fossil fuels.