Lattice Boltzmann Simulation of Calcite Precipitation in Pore Systems

The lattice-Boltzmann (LB) method can be used to simulate aspects of chemical reactions such as mineral precipitation from a fluid phase. It has the advantage of allowing the solute phase to evolve depending on local conditions, so that the controls on precipitated phase grain shape can be studied simultaneously with the controls on chemical compositions and growth rate. We have used the LB approach to investigate the cementation in pores from precipitation of calcite in oversaturated water as a continuing effort in developing methods for treating complex chemical reaction problems. Specific research question is what maintain fluid flowing unimpeded until the pore space completely filled by precipitates. The formation of calcite is a classic problem in diffusion and reaction-limited mineral growth. In this study we describe the LB approach used, address the strategy for properly solving the fourth-order polynomial for carbonate system, perform the scaling of the calculations to actual physical problems, and simulate the growth of crystals in pore systems under various physical and chemical conditions. Our study shows that diffusion plays a critical role in the reactive transport. The results provide insights into the controlling processes in calcium carbonate interactions.