CO_2咸水层封存中组合盖层密封效果的影响因素

Factors of sealing efficiency of combined caprocks for CO_2 storage in saline aquifer

为了研究组合盖层的密封效果,设计了对比工况,研究了不同形式和岩性条件下组合盖层密封效果的差异,从而确定了组合盖层密封效果的关键影响因素。研究结果表明:组合盖层的层数、层厚、薄砂岩层渗透率及孔隙度是影响密封效果的主要因素。层数越多,密封效果越好。薄储层的厚度会影响CO2的总封存容量,对密封效果也有一定的影响。渗透率和孔隙度越大,则CO2沿着薄砂岩层向远处迁移越容易,密封性也越好。因此,在选址时,不仅要尽量选择有组合盖层的储盖组合,更应该选取盖层层数多、薄砂岩层渗透率高和孔隙度大的组合盖层的储盖组合。

For studying of sealing efficieny of combined caprocks, the authors designed different cases to study the sealing effects of different combined caprocks. The results show that the layer number, thickness, permeability and porosity of thin reservoirs are main factors which influence the sealing efficiency of combined caprocks.More layers and bigger permeability and porosity result in better efficiency, also, the thickness of thin reservoirs will influence the CO2 capacity. Therefore, for site selection, combined caprocks can be a good choice,but combined caprocks with more layers and bigger permeability and porosity would be a better one.