Tracking CO2 Geosequestration Using Downhole Gravity Gradiometry, Otway Basin, Victoria, Australia.

Abstract:

Carbon dioxide sequestration is a vital technique for the mitigation of greenhouse gas emissions and anthropogenic global warming. The viability of CO₂ geosequestration, and the ability to prevent any leakage or migration depends on the capacity to monitor, and model, the CO₂ reservoir. Downhole gravity gradiometry offers an additional capability to CO₂ monitoring, and here we demonstrate the downhole gradient effect of CO₂ injection at the Otway Basin, Victoria, by the CO2CRC corporation. Data from reservoir modelling has been simulated to calculate gravity gradients to gain an understanding of the behaviour of CO₂ once injected into geological storage. Monte Carlo simulations were utilised to determine the uncertainties inherent in the deep subsurface. Presently; models have been created to demonstrate the response caused by the injection of CO₂, and we present a statistical analysis to constrain the uncertainties posed by the results.