Fired-Siltstone Based Geopolymers for CO2Sequestration Wells : A Study on the Effect of Curing Temperature

摘要

Wellbore integrity during Carbon Dioxide (CO₂) storage in deep aquifers is a major problem as the currently used well cement will lose its integrity at higher temperatures and eventually leads to CO₂leakage into the atmosphere. Researchers have conducted several studies in order to find a proper well cement material and have tested several types of geopolymers mixing fly ash and different type of cements with an alkaline solution curing in different temperatures. This paper presents a study on geopolymer composites made from fired siltstone, slag as well as alkaline liquid which were cured at temperatures ranging from 23°C to 80°C. Five different types of geopolymer were prepared with ratios of fired siltstone (to 700 oC) and slag as 0:100, 20:80, 30:70, 40:60 and 50:50, separately. After preparing samples with various proportions under different temperatures, the mechanical properties of them were compared. The experimental results reveal that optimum curing temperature range is 50 to 70°C and addition of higher proportion of slag would help geopolymer gain better performance on mechanical strength compared to other geopolymer materials.