Practical approaches to study microbially induced calcite precipitation at the field scale

TL;DR

This paper presents a mathematical model for field-scale microbially induced calcite precipitation (MICP) to assess its effectiveness in sealing leakage zones in geological formations, demonstrating its potential through numerical simulations.

Contribution

The paper introduces a computationally feasible field-scale MICP model that captures key biochemical and flow mechanisms for sealing leakage paths in reservoirs.

Findings

MICP can effectively reduce permeability in reservoir-caprock systems.

Numerical simulations confirm the potential of MICP for sealing leakage zones.

The model is applicable to real reservoir conditions for leakage mitigation.

Abstract

Microbially induced calcite precipitation (MICP) is a new and sustainable technology which utilizes biochemical processes to create barriers by calcium carbonate cementation; therefore, this technology has a potential to be used for sealing leakage zones in geological formations. The complexity of current MICP models and present computer power limit the size of numerical simulations. We describe a mathematical model for MICP suitable for field-scale studies. The main mechanisms in the conceptual model are as follow: suspended microbes attach themselves to the pore walls to form biofilm, growth solution is added to stimulate the biofilm development, the biofilm uses cementation solution for production of calcite, and the calcite reduces the pore space which in turn decreases the rock permeability. We apply the model to study the MICP technology in two sets of reservoir properties including a well-established field-scale benchmark system for CO$_2$ leakage. A two-phase flow model for CO$_2$ and water is used to assess the leakage prior to and with MICP treatment. Based on the numerical results, this study confirms the potential for this technology to seal leakage paths in reservoir-caprock systems.