中国深部咸水含水层CO_2储存优先区域选择

RANKING AND SCREENING OF CO_2 SALINE AQUIFER STORAGE ZONES IN CHINA

CO2地下储存可有效地减少人类活动排放到大气中的CO2量,从而缓解日趋严重的全球气候变化问题。沉积盆地地下深部存在体积巨大的咸水含水层,咸水不宜开发利用,可用来储存大量的CO2。为了选出一些将来可优先利用的储存分区并进行详细研究,在收集大量地质、水文地质、石油勘探等资料的基础上,将中国大陆地区24个主要沉积盆地分为70个储存分区,利用溶解度法计算了各储存分区地下1～3km深度内咸水含水层的CO2储存容量。根据分区内及其周边CO2集中排放量,对各分区进行了分级评价。研究结果表明,中国咸水含水层CO2储存容量达1.43505×1011t,约为2003年中国大陆地区CO2排放量的40.5倍。华北平原大部,四川盆地北部、东部和南部,准葛尔盆地东南部都是将来优先考虑的CO2含水层储存地区。东南沿海和华南大部,应考虑利用近海沉积盆地内的咸水含水层储存CO2。

Geological storage is one of potentially effective means of reducing anthropogenic atmospheric emission of CO2 to mitigate the worsening global climate change. The enormous saline aquifers deeply buried in the sedimentary basins are saturated with high concentration dissolved solids, which make groundwater unsuitable to any large-scale exploitation. Storing CO2 in such aquifers is one of good options to reduce anthropogenic CO2 emission. In order to select some preferential zones for commercial CO2 storage in the near future, 24 major sedimentary basins in China Mainland are divided into 70 sub-regions and their CO2 storage capacities in deep saline aquifers are estimated on the basis of geological, hydrogeological, water quality and geothermal data. All the sub-regions are graded into four ranks according to the CO2 storage capacities and total CO2 emission from the large-scale industrial sources inside and within 50 km and 100 km around each sub-region. The total storage capacity of CO2 reaches to 1.43505× 10^11t which is equal to 40.5 times against the total CO2 emission of China in 2003. The sites in rank I are mainly located in North China Plain, Sichuan Basin and the southeast of Junggar Basin. The sites of east and southeast China are also potential storage candidates. In southeast coastal area and South China, CO2 can be stored in the brine aquifer of sedimentary basins located on the continental shelf.