Carbon dioxide capture and sequestration (CCS) into deep geological formations is widely considered as a preferred option for reducing green house gases (GHG) in the atmosphere. The preferred storage location is the saline aquifers due to their exceptional sequestration capacity compared to depleted oil and gas reservoirs. Since CO2 is a relatively reactive substance, injecting it into an aquifer could initiate various chemical reactions with aquifer rock and cap rock. This underscores the need to plan the sequestration process carefully and to investigate possible consequences in terms of rock-fluid reactions that may affect Petrophysical properties.
The results presented here are based on a compositional reservoir simulation study of a prototypical CO2 sequestration project in a deep saline aquifer. The purpose of this study was to try to determine the effects of CO2 sequestration on the Petrophysical properties of an aquifer rock. CO2 was injected for a 10 year period, followed by 1,000 years of natural gradient flow. The impact of several parameters including temperature, vertical to horizontal permeability ratio, and salinity were also studied and the results are presented here.