15:30 〜 15:45
[BPT03-06] Ureolysis-driven microbially-induced carbonate precipitation under high-temperature and anoxic condition
キーワード：ureolysis-driven MICP, high-temperature and anoxic, calcium carbonate(CaCO3), microbial solid-free drilling fluid, subsurface geological
Microbial-induced carbonate precipitation (MICP) is an environmentally friendly, efficient, and sustainable technology that has garnered significant attention due to its applications in soil reinforcement, groundwater purification, metal remediation, and geological engineering. While traditional MICP processes are performed under aerobic conditions, many real-world applications, such as in petroleum reservoirs and deep saline aquifers, occur in high-temperature, anoxic or anaerobic environments. The applicability of ureolysis-driven MICP in such conditions remains underexplored. Therefore, studying ureolysis-driven MICP in anoxic and anaerobic environments is of great significance to geological engineering and environmental protection.
This study screening facultative anaerobic, thermotolerant ureolytic bacteria from a high-temperature anaerobic digester and investigating their ureolysis-driven MICP performance under aerobic, anoxic, and anaerobic conditions at varying temperatures (30 °C, 40 °C, and 50 °C). we also investigate the microbial growth and urease activity of microbial sodium carboxymethyl cellulose (CMC) solid-free drilling fluid under high temperature conditions at different pH, different NaCI concentrations, and different urea concentrations by the representative isolate. Finally, the performance of microbial sodium carboxymethyl cellulose solid-free drilling fluid was investigated under the optimal conditions, and the experiment of evaluating the borehole wall-enhancement was conducted to analyze the effect of microbial solid-free drilling fluid on the fractured formations and sand production.
The results show that the reaction rate and the types of minerals formed are different from those under normal temperature and aerobic conditions. Under aerobic conditions, carbonates mainly exist in the form of calcite, and under anaerobic conditions (50°C) they exist in the form of vaterite. In addition, microorganisms in microbial sodium carboxymethyl cellulose (CMC) solid-free drilling fluids can continue to grow under high alkali (pH=11) and high salt concentrations (15% NaCl) under high temperature conditions (50°C). Finally, the microbial sodium carboxymethyl cellulose (CMC) solid-free drilling fluids can effectively consolidate fine sand and broken particles. This study provides insights into MICP driven by urea decomposition in high temperature, anoxic or anaerobic environments, highlighting its potential for application in underground geoengineering.
This study screening facultative anaerobic, thermotolerant ureolytic bacteria from a high-temperature anaerobic digester and investigating their ureolysis-driven MICP performance under aerobic, anoxic, and anaerobic conditions at varying temperatures (30 °C, 40 °C, and 50 °C). we also investigate the microbial growth and urease activity of microbial sodium carboxymethyl cellulose (CMC) solid-free drilling fluid under high temperature conditions at different pH, different NaCI concentrations, and different urea concentrations by the representative isolate. Finally, the performance of microbial sodium carboxymethyl cellulose solid-free drilling fluid was investigated under the optimal conditions, and the experiment of evaluating the borehole wall-enhancement was conducted to analyze the effect of microbial solid-free drilling fluid on the fractured formations and sand production.
The results show that the reaction rate and the types of minerals formed are different from those under normal temperature and aerobic conditions. Under aerobic conditions, carbonates mainly exist in the form of calcite, and under anaerobic conditions (50°C) they exist in the form of vaterite. In addition, microorganisms in microbial sodium carboxymethyl cellulose (CMC) solid-free drilling fluids can continue to grow under high alkali (pH=11) and high salt concentrations (15% NaCl) under high temperature conditions (50°C). Finally, the microbial sodium carboxymethyl cellulose (CMC) solid-free drilling fluids can effectively consolidate fine sand and broken particles. This study provides insights into MICP driven by urea decomposition in high temperature, anoxic or anaerobic environments, highlighting its potential for application in underground geoengineering.