oa Bonaparte Basin Injectivity Modelling Partial Penetration and Salt Precipitation

INPEX is assessing the potential of the Australia G-7-AP GHG permit, located in the Bonaparte basin offshore Northern Australia, as a saline aquifer CO2 storage site.

Well injectivity is a key uncertainty to resolve for a CCS project, as it drives important decisions such as well count. In order to assess the range of CO2 well injectivity, reservoir and completion uncertainties have been taken into account and nodal analysis was performed.

Since a thick reservoir is expected, partial penetration impact was also investigated to appropriately model the injectivity in a multi-layer reservoir with crossflow within the formation. This was done using numerical models and an analytical model to compare to resulting skin factor, which was then used in the nodal analysis models. With the formation brine salinity having a range of uncertainty, the potential impact of salt precipitation on long-term injectivity was investigated by generating ranges of near-wellbore, fine-grid models, over a range of reservoir properties and injection rates.