Abstract The temperature field generated during an in-situ combustion (ISC) process sees dramatic variation from 50 °C to over 700 °C. The division of the reservoir into different temperature regions during an ISC process induces different phase state transition and chemical reactions, resulting in serious heterogeneity in oil compositions and reaction products. Combustion tube experiments were conducted to investigate the propagation behavior of combustion front, combined with outlook color observation of down-hole rock samples, permeability measurements (N2) and organic residual analysis. Fourier transform infrared spectroscopy (FTIR) and gas chromatography–mass spectrometry (GC–MS) were used to characterize the organic materials extracted from the combustion zones. X-ray diffraction (XRD) was employed to investigate the variation of mineral components before and after the ISC process. The results indicated that most of calcite component in the down-hole rock sample was decomposed in combustion front regions within the highest temperature range of 550–650 °C. The color transfer from light grey to brick-red in the outlook color observation demonstrated that an even higher temperature can be achieved. Permeability measurement had shown that secondary diagenetic reaction involving clay triggered a significant permeability reduction during the ISC process. This study demonstrated that variation of oil compositions from different locations of formation can serve as a direct indicator to the occurrence of fire chamber enlargement.

中文翻译：

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原位燃烧过程中温度场对岩石和重成分变化的影响

摘要 原位燃烧 (ISC) 过程中产生的温度场在 50 °C 到 700 °C 之间发生了巨大变化。在ISC过程中将储层划分为不同的温度区域会引起不同的相态转变和化学反应，导致石油成分和反应产物的严重非均质性。结合井下岩样外观颜色观察、渗透率测量（N2）和有机残留分析，通过燃烧管实验研究了燃烧前沿的传播行为。傅里叶变换红外光谱 (FTIR) 和气相色谱-质谱 (GC-MS) 用于表征从燃烧区提取的有机材料。采用 X 射线衍射 (XRD) 来研究 ISC 过程前后矿物成分的变化。结果表明，井下岩石样品中的大部分方解石组分在最高温度 550-650 ℃范围内的燃烧前沿区域分解。外观颜色观察中从浅灰色到砖红色的颜色转变表明可以实现更高的温度。渗透率测量表明，在 ISC 过程中，涉及粘土的二次成岩反应引发了显着的渗透率降低。这项研究表明，来自不同地层的石油成分的变化可以作为火室扩大发生的直接指标。结果表明，井下岩石样品中的大部分方解石组分在最高温度范围550-650 ℃的燃烧前沿区域分解。外观颜色观察中从浅灰色到砖红色的颜色转移表明可以实现更高的温度。渗透率测量表明，在 ISC 过程中，涉及粘土的二次成岩反应引发了显着的渗透率降低。这项研究表明，来自不同地层的石油成分的变化可以作为火室扩大发生的直接指标。结果表明，井下岩石样品中的大部分方解石组分在最高温度范围550-650 ℃的燃烧前沿区域分解。外观颜色观察中从浅灰色到砖红色的颜色转移表明可以实现更高的温度。渗透率测量表明，在 ISC 过程中，涉及粘土的二次成岩反应引发了显着的渗透率降低。这项研究表明，来自不同地层的石油成分的变化可以作为火室扩大发生的直接指标。外观颜色观察中从浅灰色到砖红色的颜色转移表明可以实现更高的温度。渗透率测量表明，在 ISC 过程中，涉及粘土的二次成岩反应引发了显着的渗透率降低。这项研究表明，来自不同地层的石油成分的变化可以作为火室扩大发生的直接指标。外观颜色观察中从浅灰色到砖红色的颜色转移表明可以实现更高的温度。渗透率测量表明，在 ISC 过程中，涉及粘土的二次成岩反应引发了显着的渗透率降低。这项研究表明，来自不同地层的石油成分的变化可以作为火室扩大发生的直接指标。