Thermo-Fluid-Dynamical Modelling of Salt Precipitation During Co2 Injection in Saline Aquifers, and the Effect on Injectivity

Abstract

CO2 injection is a crucial part of CCS technology. To enable the injection and storage of many gigatonnes of CO2 per year, a large number of injection wells are needed, and it is important to understand the physics of CO2 injection in general and of salt precipitation in particular. Salt precipitation in the near-well region can lead to reduced permeability and subsequent reservoir damage. To be able to consistently model the salt precipitation, it is necessary to combine highly accurate equations of state (EoS) for the thermodynamic properties and phase compositions together with the fluid-dynamical models in a consistent fashion. The present work develops such a combination which enables the simulation of injection with analysis of the precipitation and injectivity loss, and thus makes possible parameters studies to identify the cases where precipitation is an operational risk.