Kinetics Study On Hydrolysis And Hydrocarbon Generation Of The Mixed Fatty Acid Ester Catalyzed By Immature Oil Source Rocks At Low Temperature

It is an important aspect in cause of immature oil formation that hydrocarbon from decarboxylation of fatty acid or ester catalyzed by minerals at low temperature. Fatty acid in immature oil source rocks are regarded as one of the important precursors for generating hydrocarbons. It is the fatty acid esters that is the main forms of the fatty acids existing in the nature. The role that the immature oil source rocks had played in the process of hydrocarbon from fatty acid or esters,which was introduced in the test. The active energy of hydrocarbon from fatty acid or ester decarboxylation catalyzed by minerals at low temperature is illuminated from thermodynamics.The high pressure kettle was applied in the closed and water existed system. In this test, the seven immature oil source rocks (Daqing, Liaohe, Dagang, Shengli, Subei, Biyang, Jianghan) are chosen as catalysts to study the hydrolysis and hydrocarbon-generating of fatty acid esters. To make up the lack of the studies in the past, we chose the mixed fatty acid esters as the model compound (methyl myristate, methyl palmitate, methyl state). The content of this study include: studying the environment and the component of immature oil source rocks; The factors such as the temperature, pressure, value of pH and the salinity which influenced the reaction catalysed by immature oil source rocks were studied; In the same condition, studying interaction among the mixed esters and comparing the activity of the hydrolysis and hydrocarbon-generating catalysed by the seven immature oil source rocks; A series of simulation experiments such as hydrolysis and hydrocarbon-generating carried out at the conditions gotten by the analysis of the environment of immature oil source rocks; Estimating the years and quantity of hydrocarbon-generating. At the last, the results indicate that the seven immature oil source rocks all played an important role in reaction of hydrolysis and hydrocarbon-generating. According these experiments, we found that the temperature, pressure, pH value and the salinity had some different influences in the reaction, but we found that the temperatue played an important role in the reaction compared with the other reaction conditions. There were some competitions in the reaction of hydrolysis and hydrocarbon-generating catalysed by immature oil source rocks when it was going on. We also found that the more the clay in immature oil source rocks, the greater the ratio of hydrolysis of the mixed esters; the more the carbonate in immature oil source rocks, the greater the ratio of hydrocarbon-gengerating of the mixed esters. By simulated experiments,we got that the reactions of hydrolysis and hydrocarbon-generating catalysed by immature oil source rocks at low temperature were first order reaction. In a word, the immature oil source rocks played an unsubstituted role in reaction of carbon-generating.