DISTRIBUTION OF BIOGAS SOURCE ROCKS OF ACID OXYGENATES

摘要

The maturation of source rocks from Cretaceous Ordos Basin is low, with vitrinite reflectance of 0.32-0.71%. Non-acidic hydrocarbon soluble organic matters are mainly composed of n-monobasic acid, n-dicarboxylic acid, acid pristine, phytanic acid, hopanes acid and sterol acid and other components. The n-monobasic acid content is dominate and showed two distributed forms, and various forms showed even odd advantage. Levels of n-dicarboxylic acid are low. Content of hopanes acid is higher than sterane acid. It is because of the acidic oxygen-containing compounds, especially n-alkyl fatty acid, which arise decarboxylase reaction. The CO2 are produced while n-alkanes are formed, which not only provide a lot of nutrients for methanogens energy, but also provide a matrix of respiratory metabolism.