Abstract The multi-phase flow characteristics and preferential paths in the heterogeneous pore structures of reservoir rocks at high pressures and temperatures are much significant to evaluate the exploitation efficiency of subsurface hydrocarbon resources and carbon sequestration effects. Therefore, these characteristics and paths should be accurately described and understood. However, only a few existing evaluation models consider the effect of thermo-hydro (T-H) coupling on these characteristics and paths. In this study, based on the commercial programs COMSOL with MATLAB, we developed a T-H coupling flow model to characterize the immiscible two-phase interface dynamics and flow paths in heterogeneous pore structures at various two-phase temperature differences. Ten numerical cases were carried to evaluate the effects of the reservoir and injection temperatures on the preferential paths of two-phase flow in the same two-phase temperature difference range. The results indicate that during CO2-water non-isothermal displacement process, the reservoir temperature affects the preferential paths of two-phase flow and injection temperature has a larger effect on branch flow in small pore regions. The injection rate considerably affects the two-phase flow paths as a result of temperature effects. This study provides a reference for quantitatively analyzing multi-phase flow in reservoir rocks at formation temperatures.

中文翻译：

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高温下非均相多孔结构中不混溶两相流的热-水耦合模型

摘要 高压高温下储集岩非均质孔隙结构中的多相流特征和优先路径对于评价地下油气资源的开发效率和固碳效果具有重要意义。因此，应该准确地描述和理解这些特征和路径。然而，只有少数现有评估模型考虑了热-水力 (TH) 耦合对这些特性和路径的影响。在本研究中，基于 COMSOL 和 MATLAB 的商业程序，我们开发了一个 TH 耦合流动模型来表征不同两相温差下异质孔隙结构中的不混溶两相界面动力学和流动路径。通过10个数值算例，评价了储层温度和注入温度对同一两相温差范围内两相流优先路径的影响。结果表明，在CO2-水非等温驱替过程中，储层温度影响两相流的优先路径，注入温度对小孔隙区分支流的影响较大。由于温度的影响，注射速率对两相流动路径有很大影响。该研究为定量分析地层温度下储层岩石中的多相流提供了参考。储层温度影响两相流的优先路径，注入温度对小孔隙区支流影响较大。由于温度的影响，注射速率对两相流动路径有很大影响。该研究为定量分析地层温度下储层岩石中的多相流提供了参考。储层温度影响两相流的优先路径，注入温度对小孔隙区支流影响较大。由于温度的影响，注射速率对两相流动路径有很大影响。该研究为定量分析地层温度下储层岩石中的多相流提供了参考。