مدلسازي سينتيك واكنشهاي احتراق درجا و بررسي مكانيسمهاي موثر در آن براي مخازن نفت سنگين

چكيده انگليسي :

Modeling of Reactions Kinetics and Study of Effective Mechanisms of In Situ Combustion Process at Heavy Oil Reservoirs Mehdi karami Mehdi karami64@gmail com Date of submission May 4 2013 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor M R Ehsani EhsaniMR@cc iut ac ir Abstract Heavy oil as one of the world s hydrocarbon resources has special characteristics that differentiate it from other instances of oil in the world Density and viscosity of this oil result in different kind of extraction from other lighter naphtha Normally this type of oil is immobile So that in some parts of Canada where the oil is spread on the surface of the earth surface drilling machines are used transfer to it to downstream processes The mobility of the subsurface oil must be increase in order to be extracted In situ combustion method is the most important method to extract the heavy oil fields In this method some amounts of have oil in the reservoir is burned to increase the temperature of the remained oil So the viscosity and gravity of the oil are decreased in the way that the mobility is increased To determine the optimized condition in the in situ combustion process it is essential to have synthetic parameters of this reaction such as activation energy pre exponential factor and the reaction mechanism as an approximate Accordingly various techniques have been proposed In practice different reactions occur when burning a fuel mixture which are generally not possible to predict But it is not too far fetched to introduce a good way to specify the behavior of the burning Kissinger method as a subset of integral method is widely used in the literature It is generally used to predict the activation energy of the reaction However in this method it is assumed that the temperature varies linearly with time While this assumption is valid for gravimetery analyzers it is not more valid for real systems In a burning reaction there may be some exothermic or endothermic reaction which may slant the temperature from the pre estimated temperature Here we proposed a new method based on the Kissinger method in which the so called assumption was ignored In this study the results of new method was compared with those of Kissinger and Vyazokin methods It was shown that the new method could predict the activation energy extracted from Vyazokin method with a good accuracy While the Vyazokin method is based on a trail and error procedure the new method can predict the activation energy explicitly Master plot method was also used to predict the pre exponential factor Eighteen different reaction models were used to enhance the accuracy Use of CMG simulator and the so described synthetic parameters a combustion tube was simulated The mechanism of the reaction was extracted from the PDF created with pdfFactory trial version www pdffactory com

كرمي، مهدي

مدلسازي سينتيك واكنشهاي احتراق درجا و بررسي مكانيسمهاي موثر در آن براي مخازن نفت سنگين