CO₂ injection into a reservoir with marginal permeability (≲ 10⁻¹⁴ m²) could induce pressure high enough to fracture the reservoir rock and/or caprock. A pressure‐driven fracture can immensely enhance the injectivity and would not compromise the integrity of the overall storage complex as long as the fracture is contained vertically. Conventional models for geologic carbon storage simply treat fractures as high‐permeability conduits, ignoring coupled interactions between the fluids, the fracture, the reservoir, and caprock. We employ a high‐fidelity model coupling multiphase flow, heat transport, poroelasticity, thermal contraction, as well as fracture mechanics to study thermo‐poroelastic responses of a pressure‐driven fracture in a carbon storage reservoir. We found that poroelasticity dictates that to maintain an open fracture in the reservoir rock requires a continuous and significant increase of pressure, potentially exceeding the fracturing pressure for the caprock. A closed‐form equation is derived to conservatively compute the pressure increase. Although cooling in the near‐well region could reduce the fracture‐opening pressure, the fracture propagation pressure is still dictated by processes in the far‐field rock unaffected by the cooling. This discrepancy causes a high net pressure near the injection well and could further drive the fracture into the caprock. However, while such fracturing is likely, we demonstrate that in many instances we can expect it to be contained.

中文翻译：

---

碳储层中压力驱动裂缝的热孔隙弹性响应及其对注入性和盖层完整性的影响

将CO ₂注入具有边际渗透率（≲10 ^-14 m ²的油藏）中）可能会引起足够高的压力，使储层岩石和/或盖层破裂。压力驱动的裂缝可以极大地提高注入能力，并且只要裂缝是垂直容纳的，就不会损害整个储层的完整性。常规的地质碳储量模型只是将裂缝视为高渗透率的管道，而忽略了流体，裂缝，储层和盖层之间的耦合相互作用。我们采用耦合多相流，热传输，多孔弹性，热收缩以及裂缝力学的高保真模型来研究碳储层中压力驱动裂缝的热多孔弹性响应。我们发现，孔隙弹性要求维持储层岩石中的开放裂缝需要持续且显着增加压力，可能会超出盖层的破裂压力。可以得出一个封闭形式的方程式，以保守地计算出压力增加。尽管在近井区域进行冷却可以降低裂缝的张开压力，但裂缝传播压力仍受不受冷却影响的远场岩石过程的控制。这种差异会在注入井附近造成较高的净压力，并可能进一步将裂缝驱入盖层。但是，尽管可能发生这种破裂，但我们证明，在许多情况下，我们可以预期它会被遏制。裂缝扩展压力仍然是由远场岩石中不受冷却影响的过程所决定的。这种差异会在注入井附近造成较高的净压力，并可能进一步将裂缝驱入盖层。但是，尽管可能发生这种破裂，但我们证明，在许多情况下，我们可以预期它会被遏制。裂缝扩展压力仍然是由远场岩石中不受冷却影响的过程所决定的。这种差异会在注入井附近造成较高的净压力，并可能进一步将裂缝驱入盖层。但是，尽管可能发生这种破裂，但我们证明，在许多情况下，我们可以预期它会被遏制。