# Field-scale optimization of injection strategies for leakage mitigation using microbially induced calcite precipitation

**Authors:** Svenn Tveit, David Landa-Marbán  
**arXiv:** [2201.00669](https://arxiv.org/abs/2201.00669)  
**Date:** 2022-01-03  
**Summary page:** https://www.summarizepaper.com/en/arxiv-id/2201.00669v2/

## Key points

- Optimization procedure for sealing leakage paths using MICP in CO$_2$ storage context
- Utilization of field-scale MICP mathematical model in OPM Flow with EnOpt algorithm
- Objective function to maximize calcite precipitation in shortest operational time
- Innovative injection strategy to efficiently produce calcite while avoiding clogging unwanted areas
- Application of optimization procedure to three synthetic CO$_2 leakage scenarios, demonstrating effectiveness
- Successful closure of leakage paths in all scenarios, highlighting potential for mitigating CO$_2 leakage risks
- Incorporation of economic considerations into optimization process for cost-effective sealing of leakage paths

## Summary

The study presents an optimization procedure for sealing leakage paths using microbially induced calcite precipitation (MICP) in the context of CO$_2$ storage. The research utilizes a field-scale MICP mathematical model implemented in the industry-standard simulator Open Porous Media (OPM) Flow and employs the ensemble-based optimization (EnOpt) algorithm to solve the optimization problem. The objective function is designed to maximize calcite precipitation within the shortest possible MICP operational time. An innovative injection strategy is developed to efficiently produce calcite in and around the leakage paths while avoiding clogging unwanted areas of the reservoir, such as the near-well region. This strategy involves simultaneous injection of growth and cementation solutions in separate well segments to initiate the MICP process after establishing a biofilm in the leakage paths during an initial injection phase. The optimization procedure is applied to three synthetic CO$_2$ leakage scenarios, demonstrating its effectiveness in sealing leakage paths while minimizing total MICP operational time. The results show successful closure of leakage paths in all scenarios, highlighting the potential of this approach for mitigating CO$_2$ leakage risks. Additionally, economic considerations are incorporated into the optimization process by weighing calcite precipitation at leakage paths against total injection and no-flow time, ensuring cost-effective sealing of leakage paths. Overall, this study contributes valuable insights into optimizing injection strategies for field-scale application of MICP for leakage mitigation, showcasing its potential for enhancing CO$_2$ storage security and efficiency.