Low Temperature Oxidation of Heavy Crude Oil: Experimental Study and Reaction Modeling
Date
2014-02-05
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
In situ combustion (ISC) or air injection is one of the oldest thermal methods for enhanced oil recovery. In this technique, air or oxygen-enriched air is injected into the formation. A portion of the oil combusts in situ and provides heat, water, and product gases. Within the oil formation, three major combustion regions can be recognized: Low Temperature Oxidation (LTO), Thermal Cracking (TC), and High Temperature Oxidation (HTO). LTO provides fuel for HTO to sustain the combustion front. Therefore the success of ISC process directly depends on quality and quantity of LTO residues. The research documented in this thesis comprises four studies. The first study consisted of experimental investigations to evaluate the thermal behavior and reaction kinetics of an Alaskan and Lloydminster heavy oils by using thermogravimetric methods to examine isothermal and ramped temperature oxidation reactions. The results revealed that there are different subzones within the LTO zone with different reaction behaviors. In the second study, an LTO reaction conceptual scheme was developed based on the elemental studies. In the third study, a multiple subzone LTO reaction model was created, suitable for use in thermal reactive reservoir simulators. Based on the fourth study, LTO region was divided into two temperature subintervals with contrary reactive behaviors based on the moisture contents of the heavy oil samples. The results of the research provide overall insight about the LTO region, its subranges, major products within each subranges, and how to model it. This equips the ISC process the flexibility of controlling the temperature or water content to produce value-added LTO residues to sustain the combustion front. For instance if more heat is needed to keep the combustion front propagating, the temperature can be controlled in subzone that produce LTO residues with higher heating values or if air requirement is a concern temperature or water content can be controlled to produce residues with higher C/H ratios.
Description
Keywords
Engineering--Petroleum
Citation
Khansari, Z. (2014). Low Temperature Oxidation of Heavy Crude Oil: Experimental Study and Reaction Modeling (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/26800