Abstract Coupled thermo-hydraulic-mechanical behavior of saturated porous media with low permeability is of crucial significance to multiple operations including thermal treatment for declogging wellbores, thermal fracturing during production of unconventional shale oil, radioactive-waste disposal, and soft tissue and tumor growth. This work presents new thermo-poroelastic solutions for an isotropic medium subjected to a constant fluid flux and a localized heat source, incorporating two novel components: (a) transient flow transfer between the source and the embedding layer, thus incorporating the temporal thermo-poroelastic changes in the stress state adjacent to the source; and (b) vertical confinement effects on the mechanical response of the target zone, governed by the stiffness of the sealing media using the Winkler model approximation. The Westerly Granite is selected to assess the thermo-poroelastic alterations induced under the imposed fluid flux and heat loads. Results reveal generation of short-term thermal-induced pore pressures subsequent to injection initiation which otherwise cannot be predicted using current solutions. The new solutions capture higher thermal induced pore pressures and a more rapid dissipation under a higher heat transition rate between the source and the target zone. A compassion between the response of the porous layer under constant fluid flux and localized heat source, versus localized heat and flow sources reveals the former loading to be the most effective for localized thermal treatment as it results in: notably higher thermal-induced pore pressures, the maximum thermal-induced pressures to occur in the source vicinity; and particularly slower dissipation of the thermal-induced pore pressures. The stress paths demonstrate slight initial dilation before compaction under the latter loading; while the former results in an initial compaction with higher deviatoric stresses proceeded by dilation once the thermal-induced pore pressures tend to dissipate. Stress paths reveal the vertical confinement to remarkably impact the response of a porous layer. Higher compaction is generated under higher vertical confinement. In case of a mechanically free source-medium interface, lower vertical confinement gives rise to higher deviatoric stresses and lower mean stresses during the initial compaction phase, in addition to causing the formation to undergo dilation much sooner compared to when higher confinement is applied. For a mechanically fixed boundary setting, higher deviatoric stresses are generated under higher vertical confinements.

中文翻译：

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恒定流体通量和局部热源下的热多孔弹性

摘要 低渗透饱和多孔介质的热-水-力耦合行为对井筒解堵热处理、非常规页岩油生产热压裂、放射性废物处理、软组织和肿瘤生长等多种作业具有重要意义。这项工作为承受恒定流体通量和局部热源的各向同性介质提出了新的热孔弹性解决方案，其中包含两个新组件：（a）源和嵌入层之间的瞬态流动传递，从而结合了时间热孔弹性源附近应力状态的变化；(b) 垂直约束对目标区域机械响应的影响，由使用 Winkler 模型近似的密封介质的刚度控制。选择西风花岗岩来评估在施加的流体通量和热负荷下引起的热多孔弹性变化。结果表明，在注入开始后会产生短期的热致孔隙压力，否则无法使用当前的解决方案进行预测。新的解决方案在源区和目标区之间更高的热转换率下捕获更高的热致孔隙压力和更快速的耗散。多孔层在恒定流体通量和局部热源下的响应与局部热源和流动源之间的同情表明，前一种载荷对于局部热处理最有效，因为它导致：显着更高的热致孔隙压力，源附近发生的最大热致压力；尤其是热致孔隙压力的消散更慢。应力路径在后一载荷下压实前表现出轻微的初始膨胀；而前者导致初始压实，一旦热致孔隙压力趋于消散，就会通过膨胀进行更高的偏应力。应力路径揭示了垂直限制对多孔层响应的显着影响。在更高的垂直约束下产生更高的压实度。在机械自由的源 - 介质界面的情况下，与应用更高的限制相比，除了导致地层更快地进行扩张之外，较低的垂直限制会在初始压实阶段产生更高的偏应力和更低的平均应力。对于机械固定的边界设置，