Micro-CT Imaging of Chemical Dissolution of Carbonate Rock

The microstructure of carbonate rocks experiences significant changes under reactive processes, inparticular chemical dissolution and deposition including dissolution-released fines migration occurringduring acidizing of petroleum reservoirs. A better understanding of such changes at the pore scale andtheir influences on rock properties is of great value for the effective design and implementation of reactiveprocesses in reservoirs. In this paper, we demonstrate the use of X-ray micro-computed tomography(micro-CT) to non-destructively visualize local porosity changes in a microporous carbonate core sampleduring chemical dissolution. A dissolution experiment in a carbonate core sample by a non-acidic solutionis designed such that changes in pore space from before to after the reactant injection could be imaged inexactly the same locations using micro-CT at resolution of less than 5 μm. The micro-CT images reveal aquasi-uniform dissolution pattern in the core sample and allow characterizing the accompanying migrationof fines within the core sample. The results provide insight into pore scale characterization of reactive flowprocesses and their effects on the evolution of rock properties.

کلیدواژه ها:

X-ray micro-CT ، Dissolution ، Deposition ، Carbonate rock