Quantifying Efficiency Of Field-Wide Geophysical Surveys For Verifying CO2 Plume Conformance During Storage Operations

To manage risks in CO2 storage operations, monitoring systems need to be designed such that the data can inform the operator whether the storage site will continue to behave as expected or not. In order to compare the benefits of different monitoring strategies, we require a measure of ‘efficiency' that is based on a balance between monitoring cost on the one hand and reliability of conformance determination on the other. In this work, we present a workflow to quantify, in terms of conformance verification metrics, the contribution of monitoring strategies with various time-lapse geophysical survey configurations (i.e., different survey acquisition times and coverage) in the presence of geological uncertainties. We illustrate the use of the methodology with a simple case study where conformance is associated with regulatory safety bounds for the development of the CO2 plume. The proposed approach can be used to assist operators in the design of monitoring strategies that can ensure compliance with regulation requirements at a reasonable cost. © 2018 European Association of Geoscientists and Engineers, EAGE. All rights reserved.