The traditional two_phase structural model of coal based on the chemical covalence bonding has to be revised since recent discoveries of powerful mixed solvent such as CS-2/C-5H-9N, giving extra high yields in coal ex...The traditional two_phase structural model of coal based on the chemical covalence bonding has to be revised since recent discoveries of powerful mixed solvent such as CS-2/C-5H-9N, giving extra high yields in coal extraction at room temperature. It is believed that the physically associated interactions play important roles in the structure of coal. A composite model of coal is suggested. The organic matter of coal is mainly composed of some parts: the rigid 3_D macromolecules linked with chemical bonds; the polar molecules of high and moderate molecular weights, corresponding to asphaltenes and resins; the hydrocarbons with lower molecular weights. The polar molecules are associated by physical interactions (such as hydrogen bonding, charge transfer interactions, π_π interactions of aromatic sheets, etc.) each other and with macromolecules to form the network structure, in which some smaller nonpolar molecules are trapped. Based on the new concept of the composite coal model, some considerations for the generation mechanism of oil from coal have approached. Since the energy level of physical association is much lower than the chemical covalent bonding, the upper threshold of oil window for the generation of oil from coal seems not to be limited strictly after the theory of oil generation at the latter stage of the kerogen maturation. It looks reasonable to pay more attention to the geological conditions including the salt, water, minerals and environments of the sedimentation. The evolution process of physically associated interactions in the composite structure of coal and the generation of oil is thought to be intimately influenced by these factors.展开更多
THE expulsion of hydrocarbons from coal is controlled by two main factors. The first is theproperties inherited from coal itself and contains two implications. One is original potential ofhydrocarbon generation from c...THE expulsion of hydrocarbons from coal is controlled by two main factors. The first is theproperties inherited from coal itself and contains two implications. One is original potential ofhydrocarbon generation from coal, which determines the degree of oil-bearing saturability;展开更多
The characteristics of coal pores and the interaction relationship between hydrocarbons and pores in coal are analysed based on the typical example of oil from coal in Tuha Basin, pointing out that the interaction bet...The characteristics of coal pores and the interaction relationship between hydrocarbons and pores in coal are analysed based on the typical example of oil from coal in Tuha Basin, pointing out that the interaction between hydrocarbon molecules and coal pore surface particles is a major controlling factor of expulsion of oil from coal. Distribution characteristics of coal pores and the ability of hydrocarbon generation are inner factors of the expulsion of the oil from coal; tectonic compressive shear stress is an external force of the expulsion of oil from coal; expulsion of the oil from coal has greater geochromatographic effect than that from mudstone, the low mature stage (or vitrinite reflectance R\-o is less than 0.9%) is advantageous to the coal-formed oil expulsion and migration; hydrocarbons in the hydrocarbon network are linked with carrier beds (such as fault), through the pore network and fissure which are connected with each other, which constitutes the main pathway of expulsion and migration.展开更多
文摘The traditional two_phase structural model of coal based on the chemical covalence bonding has to be revised since recent discoveries of powerful mixed solvent such as CS-2/C-5H-9N, giving extra high yields in coal extraction at room temperature. It is believed that the physically associated interactions play important roles in the structure of coal. A composite model of coal is suggested. The organic matter of coal is mainly composed of some parts: the rigid 3_D macromolecules linked with chemical bonds; the polar molecules of high and moderate molecular weights, corresponding to asphaltenes and resins; the hydrocarbons with lower molecular weights. The polar molecules are associated by physical interactions (such as hydrogen bonding, charge transfer interactions, π_π interactions of aromatic sheets, etc.) each other and with macromolecules to form the network structure, in which some smaller nonpolar molecules are trapped. Based on the new concept of the composite coal model, some considerations for the generation mechanism of oil from coal have approached. Since the energy level of physical association is much lower than the chemical covalent bonding, the upper threshold of oil window for the generation of oil from coal seems not to be limited strictly after the theory of oil generation at the latter stage of the kerogen maturation. It looks reasonable to pay more attention to the geological conditions including the salt, water, minerals and environments of the sedimentation. The evolution process of physically associated interactions in the composite structure of coal and the generation of oil is thought to be intimately influenced by these factors.
文摘THE expulsion of hydrocarbons from coal is controlled by two main factors. The first is theproperties inherited from coal itself and contains two implications. One is original potential ofhydrocarbon generation from coal, which determines the degree of oil-bearing saturability;
文摘The characteristics of coal pores and the interaction relationship between hydrocarbons and pores in coal are analysed based on the typical example of oil from coal in Tuha Basin, pointing out that the interaction between hydrocarbon molecules and coal pore surface particles is a major controlling factor of expulsion of oil from coal. Distribution characteristics of coal pores and the ability of hydrocarbon generation are inner factors of the expulsion of the oil from coal; tectonic compressive shear stress is an external force of the expulsion of oil from coal; expulsion of the oil from coal has greater geochromatographic effect than that from mudstone, the low mature stage (or vitrinite reflectance R\-o is less than 0.9%) is advantageous to the coal-formed oil expulsion and migration; hydrocarbons in the hydrocarbon network are linked with carrier beds (such as fault), through the pore network and fissure which are connected with each other, which constitutes the main pathway of expulsion and migration.
