Processes of migration and accumulation of oil and gas: studying and representation at the present stage
The subject of the study is the processes of migration and accumulation of oil and gas. The problem of migration and accumulation of oil and gas is very multifaceted. The complexity of this problem gave in due time great opportunities for a variety of constructs and brought to life a huge number of all sorts of hypotheses and theories. Oil and gas become of industrial importance when they enter the reservoir rocks and concentrate in the deposits. Oil and gas are initially scattered in clay and carbonate rocks in the form of dissolved particles in undissolved organic matter. The process of transporting oil and gas to the reservoirs is called primary migration. The starting material (kerogen) is present in the parent rocks and is the source of the bulk of hydrocarbon compounds. In order for the organic matter to be transformed, energy is needed, which is contained in the sediments themselves and organic matter. Organic matter in various concentrations is present in virtually all types of sedimentary rocks, ranging from the oldest - the Archaean-Proterozoic and up-to-date. Then comes the next stage - the concentration of hydrocarbons and ak-cumulation of them into oil and gas deposits. This process is called secondary migration. Accumulation of oil and gas can not occur if a trap is not formed. The trap can be formed during one geological period or throughout the entire stage of deposition of productive rocks. Water, oil and gas can migrate and vertically, from top to bottom and from bottom to top. Using the example of the study of the rocks of the terrigenous Devonian in the Volga-Ural oil and gas province, within Bashkirsky it was established that the formation of deposits of this territory occurred due to overlying oil reservoirs because of zones with increased reservoir pressure that prevent migration upwards. When considering the issues of migration and accumulation of oil and gas, it is necessary to take into account the geological conditions of migration and accumulation and the range of migration of oil and gas.