TY - JOUR
T1 - Experimental and Mechanism Study on Crude Oil Spontaneous Ignition during the Air Injection Process
AU - Yue, Ping
AU - Huang, Siyuan
AU - Zeng, Fancheng
AU - Sheng, James J.
AU - Jiang, Qi
N1 - Funding Information:
This work is supported by the China Postdoctoral Science Foundation under Awards 2019M663562 and 2019M650965, the National Major Projects China under Award 2016ZX05048-002, the Science & Technology Department of Sichuan Province under Award 2018FZ0070, the Natural Science Foundation of China under Award 51974263, and the Fund of State Key Laboratory (SKL) of Oil & Gas Reservoir Geology and Exploitation Engineering under Award PLN2019020.
Publisher Copyright:
Copyright © 2020 American Chemical Society.
PY - 2020/6/18
Y1 - 2020/6/18
N2 - The spontaneous ignition behavior is considered as one of the most important factors to the success of air injection process (AIP) application. Although the theory of crude oil spontaneous ignition is easy to understand, this phenomenon turned out to be difficult to capture in the lab. In this study, the Frank-Kamenetskii method was applied to investigate the spontaneous ignition of the crude oil sample both theoretically and experimentally. The thermal experiments were performed to study the thermal oxidative characteristics of crude oil samples and obtain their kinetic data. The kinetic data and typical reservoir properties were used to predict the spontaneous ignition, and the oven tests with a mixture of crude oil and sand samples were performed to validate the predictions. The experimental results of crude oil spontaneous ignition failed to prove the predictions made by the Frank-Kamenetskii theory, which implies that the complicated oxidation reactions of crude oil cannot be considered as one single-step reaction with a constant fuel ratio in the low-temperature oxidation stage, and the uniformly distributed heat within the body of the sample also needs to be reconsidered. Also, this study shows that the coke does not produce tremendous heat under low-temperature conditions, although the coke may be important for sustaining the combustion after the combustion front was already developed, and it does not contribute to the spontaneous ignition process. Moreover, this study shows that the reason for spontaneous ignition failure may be because the gaseous light oil components escaped during tests, which is different compared to the real AIP practice in reservoir conditions, and the gaseous light oil components are the key for ignition. Therefore, a conventional reaction model for in situ combustion needs to consider the gaseous phase combustion, especially when predicting the spontaneous ignition.
AB - The spontaneous ignition behavior is considered as one of the most important factors to the success of air injection process (AIP) application. Although the theory of crude oil spontaneous ignition is easy to understand, this phenomenon turned out to be difficult to capture in the lab. In this study, the Frank-Kamenetskii method was applied to investigate the spontaneous ignition of the crude oil sample both theoretically and experimentally. The thermal experiments were performed to study the thermal oxidative characteristics of crude oil samples and obtain their kinetic data. The kinetic data and typical reservoir properties were used to predict the spontaneous ignition, and the oven tests with a mixture of crude oil and sand samples were performed to validate the predictions. The experimental results of crude oil spontaneous ignition failed to prove the predictions made by the Frank-Kamenetskii theory, which implies that the complicated oxidation reactions of crude oil cannot be considered as one single-step reaction with a constant fuel ratio in the low-temperature oxidation stage, and the uniformly distributed heat within the body of the sample also needs to be reconsidered. Also, this study shows that the coke does not produce tremendous heat under low-temperature conditions, although the coke may be important for sustaining the combustion after the combustion front was already developed, and it does not contribute to the spontaneous ignition process. Moreover, this study shows that the reason for spontaneous ignition failure may be because the gaseous light oil components escaped during tests, which is different compared to the real AIP practice in reservoir conditions, and the gaseous light oil components are the key for ignition. Therefore, a conventional reaction model for in situ combustion needs to consider the gaseous phase combustion, especially when predicting the spontaneous ignition.
UR - http://www.scopus.com/inward/record.url?scp=85088915654&partnerID=8YFLogxK
U2 - 10.1021/acs.energyfuels.0c01206
DO - 10.1021/acs.energyfuels.0c01206
M3 - Article
AN - SCOPUS:85088915654
VL - 34
SP - 7076
EP - 7084
JO - Energy and Fuels
JF - Energy and Fuels
SN - 0887-0624
IS - 6
ER -