Cinética de craqueamento de hidrocarbonetos (C8) utilizando micropirólise em tubo de vidro selado aplicação em modelagem geoquímica

Abstract

One of the most fundamental problems in petroleum systems modeling, related to Oil Exploration, is to determine the limits of space and time of hydrocarbon generation in sedimentary basins. The aim of this study is to measure the kinetic parameters for cracking of lighter fractions of oil to gas, to identify the extreme geological conditions for its preservation. In order to achieve this it was developed a method using micropyrolysis MSSV (micro-scale sealed vessel) coupled with gas chromatography with flame ionization detector (GC-FID-MSSV) to assess the thermal degradation of n-octane, 2,3,4-trimethyl pentane, cyclohexane and o-xylene, pure substances that are known to be present in the oil, in order to calculate the kinetic parameters (Ea, the activation energy and frequency factor) of thermal degradation of these compounds through the Arrhenius equation. The temperature ranges used was 470 to 530 ° C and times up to 7 hours of pyrolysis. The results showed that this technique can be used to monitor the decrease of substances pyrolyzed, calculate the kinetic parameters and extrapolate to geological conditions.The kinetic parameters were obtained by two different ways, and Arrhenius Geokin. The geological conditions of temperature and time in which, according to calculations performed using the Arrhenius model, is expected to occur cracking of light fraction oil (C8) were: Initial cracking (10%) = 107 my / 126°C and final cracking (100%) = 183 my / 202°C.