Generalized oil is found in the ground or cracks in the pores of the rock is given priority to with liquid hydrocarbon and gaseous hydrocarbon combustible organic minerals. Also known as crude oil, liquid petroleum gas hydrocarbon is often referred to as natural gas.
Organic is the basis of the formation of oil and gas. Organic matter is a biological substance (mainly including phytoplankton, bacteria and higher plants) body, after death through sedimentation into sediments and buried.
The formation of oil and gas needs plenty of sedimentary organic matter, the appropriate temperature, pressure, time, bacteria and other physical and chemical and biological chemical conditions.
Temperature: the temperature is the most important factors in the process of oil and gas formation. In sedimentary basin, the temperature of the organic matter to oil source is usually between 60 degrees to 120 degrees c, as the organic matter of burial time and different. End temperature of the liquid oil generated in general is not higher than 170 degrees Celsius, the production of natural gas and liquid petroleum company, terminate the temperature higher than the density of its liquid oil, but do not generally higher than 230 degrees Celsius. In other words, the formation of oil and gas appears only in limited temperature range, temperature too low or too high is bad for the oil and gas formation.
Time: the time also play an important role in oil and gas generation, time and temperature can be complementary, but the temperature of the primary position. At very low temperatures, time has no effect generally, that is to say, If organic matter under low temperature condition, no matter how long it experience nor hydrocarbon generation.
Pressure: with the increase of sediment buried depth, overlying strata thickness increases, the temperature of the sediment, the pressure will increase. Pressure will promote chemical reaction. Pressure of oil and gas generation, however, the role of the relatively small, in some cases can promote the hydrocarbon generation, but under certain conditions can inhibit the oil and gas generation.
Bacteria: for oil and gas generation, the most significant is the anaerobic bacteria. Bacteria play an important role for the modification of the organic matter decomposition and properties. At the same time, under the low temperature decomposition of organic matter, can also produce predominantly methane biogas.
Catalyst: a catalyst is a kind of chemical reaction accelerator. Is generally thought that plays a role of catalyst to clay minerals content, its in the oil and gas generation process can promote the effect of oil and gas generation and cracking.