Feasibility of Carbonation Reactions to Control Permeability in the Deep Subsurface

Abstract

Abstract Injection and subsequent carbonation of calcium and magnesium silicate particles are proposed here as a novel strategy to grout fractures or pores and decrease fluid conductivity in the deep subsurface by taking advantage of favorable reaction kinetics. This approach could be used to manage legacy environmental risks from energy extraction techniques such as hydraulic fracturing of shale formations. To evaluate this approach, we studied the carbonation of wollastonite (CaSiO3) in the presence of ground shale under temperature and pressure (T/P) conditions broadly representative of the gas-producing regions of the Marcellus formation in the eastern United States. Effect of calcite (CaCO3) precipitation on shale particle morphology and interparticle pore structures was investigated and impacts on permeability were evaluated using batch and column experiments. Formation T/P were positively correlated with extent of carbonation. Side reactions involving calcium ions and passivation by amorphous silic...