AVO-based Reservoir Parameter Updates for Efficient Conformance of CO₂ Storage Monitoring

There are several fields of improvements in conformance monitoring where a consistent workflow for utilizing an optimal geomodel update constrained with quantitative imaging has received little attention. A consistent workflow where the CO₂ modelling results are updated with new data is not established within CO₂ storage. Here, a possible integrating workflow loop could be combining the forward reservoir modelling with inversion of geophysical data. With the goal of optimal geomodel updates, a feasibility of the conformance surveillance is proposed to be carried out through a closed loop using efficient diagnostic tools. This entails using bandlimited AVO inversion for both improved mapping of the structural attributes of the media, therein the facies classification of the present lithologies, and inversions into elastic and petrophysical properties. The petrophysical properties are furthermore transformed into a structurally sound and a consistent updated petrophysical model setting ground for the updated reservoir model.

In this work we outline the preliminary work on linearized rock physics inversion inherent in the bandlimited optimal AVO inversion. This step is necessary to link the seismic data directly to the petrophysical properties.