松辽盆地CO2地质储存适宜性评价

摘要

为缓解全球气候变暖趋势,CO2地质储存成为目前减少向大气排放CO2量的有效方法之一.区域CO2地质储存适宜性评价是筛选CO2地质储存目标区和工程建设的基础,合理的评价指标体系和指标权重对评价结果有重要影响.本次研究结合松辽盆地地质条件,建立包括地质储存规模、储存经济性、储存条件和储存安全性4个方面、20个指标、5个指标划分等级的评价指标体系,利用层次分析法(AHP)确定各指标权重,且考虑到各评价指标分级标准的模糊性,由此得到基于层次分析法的CO2地质储存适宜性的模糊综合评价方法,并将该方法应用于松辽盆地6个一级构造单元的CO2地质储存适宜性评价中,得到各一级构造单元的地质储存适宜度.评价结果表明:中央坳陷区CO2地质储存适宜性较好,可以作为CO2地质储存的优先区域,北部倾没区、西部斜坡区和东南隆起区的适宜性一般,东北隆起区和西南隆起区适宜性均较差,不适宜储存CO2.该评价结果为松辽盆地地区CO2地质储存场地筛选和工程建设等提供了科学依据.%In mitigating the trend of global warming, CO2 geological sequestration becomes one of the effective methods for reducing the amount of CO2 emissions to the atmosphere. Regional suitability assessment constitutes the basis of selecting CO2 geological sequestration target areas. Both selecting suitable evaluation indicators and determining the weights have important effects on the reasonableness of the evaluation results. Considering the geological conditions of Songliao Basin and taking six I tectonic units as the evaluation objects, the research established an index system which included 4 aspects, 20 indicators and 5 indicator levels. The 4 aspects covered the scale of geological sequestration, the economy of geological sequestration, the conditions of geological sequestration and the security of geological sequestration. Using AHP (Analysis Hierarchy Process) to determine the indicator weights, and considering the fuzziness of grading standards, the authors obtained a fuzzy synthetic evaluation method of CO2 geological sequestration based on AHP. The research applied this method to the suitability evaluation of the 6 I tectonic units and obtained the CO2 geological sequestration suitability. The results of the evaluation show that the central depression area has relatively good suitability of CO2 geological sequestration, which can hence be used as the CO2 geological sequestration priority area. It is shown that the northern plunging area, western slope area, and southeast uplift have general suitability for CO2 geological sequestration, whereas the northeast uplift area and southwest uplift area are not suitable for the geological sequestration of CO2.