轻质原油注空气热特征及氧化动力学研究

doi:10.13809/j.cnki.cn32-1825/te.2020.04.018

摘要/Abstract

摘要：

为深入分析油藏注空气过程中原油的氧化热行为,进一步发展注空气提高原油采收率技术,采用热重/微商热重—差热联用（TG/DTG-DTA）分析手段进行研究,并基于经典的Arrhenius动力学模型定量地表征原油化学组成和储层岩石对氧化活性影响的大小。原油在整个升温过程中经历了三个化学机理完全不同的反应：低温氧化、燃料沉积和高温氧化。在低温度区间原油氧化表现出一定的吸热现象。由于不同的碳烃组成,三组原油在各个反应区域表现出不同的质量损失速率,与单独原油相比,储层岩石的加入降低了原油低温和高温氧化活化能。研究表明：重质组分含量越高,原油低温氧化反应速率越大,所沉积的燃料越多,高温氧化阶段燃烧释放的热量越强;原油在高温阶段的活化能大于低温阶段,高含量的重质组分使氧化反应活化能增大;储层岩石的催化特性和比表面积作用降低原油氧化活化能,起到非均相催化氧化的效果。

关键词: 轻质原油, 热行为, 动力学分析, 原油四组分, 岩石矿物

Abstract:

In order to deeply analyze the thermal oxidation behavior of crude oil during air injection process in reservoir and further develop air injection enhance oil recovery technology, the TG/DTG-DTA analysis methods were used for study. Based on the classical Arrhenius kinetic model, the effects of oil chemical composition and reservoir rock on the oxidation activity of tested samples were quantitatively characterized. Crude oil undergoes three completely different chemical reactions during the whole heating process: low-temperature oxidation, fuel deposition and high-temperature oxidation. The oxidation of crude oil at low temperature shows a certain endothermic phenomena. Because of different hydrocarbon composition, crude oil with three samples added show different mass loss rates in each reaction area. Compared with that only contains crude oil, the addition of reservoir rocks reduces the activation energy of low temperature and high temperature oxidation. Researches show that: the higher the content of heavier components, the quicker the reaction of crude oil in LTO stage, the more fuel is deposited, and the higher the heat released from the combustion in HTO stage. The activation energy of crude oil in the high temperature stage is greater than that in the low temperature stage. High content of heavy components make the activation energy of oxidation reaction increase. The catalytic properties and specific surface area of reservoir rock reduce the activation energy of crude oil, playing an important role in the heterogeneous catalytic oxidation.

Key words: light crude oil, thermal behavior, kinetic analysis, SARA component, rock minerals

中图分类号:

TE357

侯剑锋,刘鹏刚,曹廷义. 轻质原油注空气热特征及氧化动力学研究[J]. 油气藏评价与开发, 2020, 10(4): 113-118.

HOU Jianfeng,LIU Penggang,CAO Tingyi. Thermal characteristics and oxidation kinetics study of light crude oil during air injection process[J]. Reservoir Evaluation and Development, 2020, 10(4): 113-118.

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参考文献 14

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样品	饱和烃/%	芳香烃/%	胶质/%	沥青质/%	密度/（g·cm^-3）	黏度/（mPa·s）	API/（°）
原油-1	41.535	43.256	14.483	0.725	0.859	23.624	33.235
原油-2	47.326	41.308	10.872	0.492	0.857	21.517	33.617
原油-3	48.368	42.083	9.120	0.428	0.854	20.704	34.192

样品	低温氧化（LTO）			燃料沉积（FD）		高温氧化（HTO）			燃尽温度/℃
样品	温度/℃	峰值温度/℃	质量损失/%	温度/℃	质量损失/%	温度/℃	峰值温度/℃	质量损失/%	燃尽温度/℃
原油-1	25~129	98	5.332	129~406	61.113	406~494	453	33.562	501
原油-2	25~125	74	13.401	125~409	66.061	409~516	462	20.540	517
原油-3	25~122	97	4.234	122~414	76.694	414~579	466	19.010	594
原油-1+储层岩石	25~162	132	4.741	162~397	33.730	397~476	433	16.512	527

样品	线性拟合斜率		活化能/（kJ·mol^-1）		指前因子/min
样品	LTO	HTO	LTO	HTO	LTO	HTO
原油-1	-2 556.352	-4 595.501	48.952	87.991	67 601	575 004
原油-2	-1 447.140	-4 281.890	27.710	81.990	2.572	851.140
原油-2	-1 259.130	-3 897.054	24.114	74.623	1.480	120.235
原油-1+储层岩石	-1 481.016	-3 061.673	28.363	58.621	42.650	776.240