Hydrothermal Transformation of Organic Matter of Carbonate Rock near Critical Point of Water

The mechanisms of transformation of organic matter of siliceous-argillaceous carbonate rock in a hydrothermal fluid at 340-380°C under 17-20 MPa pressure are investigated. It is shown that in a hydrothermal fluid containing excess water oxidation reaction with accumulation of aromatic hydrocarbons, resins, and asphaltenes dominates with rise of temperature and pressure and that geochemical parameters of hydrocarbons (extracts) of carbonate rock depend on the temperature and pressure of the hydrothermal fluid. The optimum thermobaric parameters of hydrothermal fluid for carbonate rock are 340°C and 17 MPa at which the amount of petroleum hydrocarbons increases while the content of organic matter decreases, the diameter of the pores increases, and micropores are formed. The obtained experimental data contribute to the development of carbonate rocks treatment technologies.