Suitability Evaluation of CO2 Geological Sequestration Based on Unascertained Measurement

Carbon capture utilization and storage (CCUS) is the primary technique to achieve large-scale industrialized CO2 emission reduction. There is a key issue on CCUS and related engineering construction, which is the suitability evaluation of CO2 geological sequestration. The suitability evaluation of CO2 geological sequestration is essentially a decision-making process in which unascertained information of various factors and attributes is involved. With the CO2 geological sequestration suitability evaluation indexes and released data, a new CO2 geological sequestration suitability evaluation model is developed based on the unascertained measurement theory and comprehensive weight which is composed of subjective weight and objective weight to reduce the errors arising from employing single weight (either subjective or objective weight) for the evaluation indexes. The new model is validated by the basin-level CO2 geological sequestration suitability evaluation of six first-level tectonic units, which are the northern plunging zone, the northeast uplift zone, the central depression zone, the western slope zone, the southeast uplift zone and the southwest uplift zone in Songliao Basin. The results indicate that the evaluation by the proposed model aligns with the previous study by the consistency of 83.33%. Since the objective weight is introduced to develop the comprehensive weight of evaluation indexes in the model, the proposed model yields a better evaluation for the northeast uplift zone. With different evaluation indexes, the proposed model is extensible to evaluate the suitability of CO2 geological sequestration at different levels.