Industrial-scale CO2 injection into deep aquifers might induce far-field pressure perturbations on the basin scale, potentially impacting other underground uses present within the same aquifer formation. In the present paper, we investigate an approach to trace back the area of elevated pressure induced by CO2 storage operations through an injection strategy in a cyclic manner over time. In this manner, the CO2 injection-induced pressure field is characterized by a low magnitude harmonic signature very specific to the considered CO2 storage, the frequency being chosen as different to naturally fluctuating phenomena or other anthropogenic underground activities. We rely on the combination of de-trending and FFT technique to detect the harmonic pattern associated the CO2 storage injections. We apply the methodology on synthetic pressure signal numerically generated using a typical injection scenario in the Paris basin case. On this basis, we discuss how trace back the CO2 storage site causing the pressure impact, in particular regarding the existing sources of noise.