中国二氧化碳地质储存目标靶区选取问题研究

Study on the Problem of Target Area Selection of CO₂ Geological Storage in China

在开展我国重点地区二氧化碳地质储存适宜性调查评价过程中,调查和评价对象选取问题和目标靶区边界条件确定的问题是困惑笔者的2大问题。通过研究国际上已经开展的二氧化碳储存工程,并结合在四川盆地目标靶区选取过程中的经验,认为:我国二氧化碳地质储存目标靶区调查评价应始于三级构造单元或局部有利构造,终于封闭的咸水含水层,或者适宜储存二氧化碳的非封闭的咸水含水层内部;在调查评价过程中,应充分考虑目标靶区边界条件,即咸水含水层的边界条件和三级构造单元及局部有力构造的物理边界条件。同时,我们在选取目标靶区时,一定要考虑源–汇匹配,有利于进一步评估二氧化碳注入目标靶区后,在深部咸水含水层中的运移和对该含水层系统中其他能源的影响。文章给出了目标靶区的评价指标体系,并指出,存在明确物理边界条件的目标靶区评价对象,建议采用层次分析–综合指数法,对于大范围的区域咸水含水层评价对象,建议采用多因子空间叠加法。

During the process of the suitability investigation and assessment of the important areas, the study and assessment object and the boundary conditions are the two problems that confuse the author. Through studying the international carbon dioxide storage projects that have been carried out, combining target selection process experience in the Sichuan Basin, we think that geological storage of carbon dioxide target investigation and evaluation should begin from three tectonic le-vels or partially favorable structures, and finish with closed saline aquifers, or suitable non-en- closed interior saline aquifer for the storage of carbon dioxide. In the course of the investigation and evaluation, we should consider objective target boundary conditions, namely, the physical boundary conditions of the saline aquifers, three tectonic levels and local favorable structure. At the same time, when we select the target, we must consider the source-sink match which is conducive to further evaluate the migration of CO2 in deep saline aquifers and the impact on other energy sources of the aquifer system. The article proposes the target evaluation index system, and points out that when a clear physical boundary condition exists, we recommend using AHP-com- prehensive index method;for large-scale regional saline aquifers evaluation, we recommend using multi-factor spatial overlay method.