Estimation of Time and Spatial Shifts in 4D Seismic Surveys Using Mutual Information and Signal Envelope
D. Donno, B. Pazetti, A. Davolio, D.J. Schiozer and J.M.T. Romano
Event name: 79th EAGE Conference and Exhibition 2017
Session: Time Lapse and PRM A
Publication date: 12 June 2017
Info: Extended abstract, PDF ( 4.18Mb )
Price: € 20
Time and spatial shift estimation in time-lapse seismic data is usually achieved using cross-correlation. While this method works generally well and it is robust in dealing with real data, it has some drawbacks. We propose here two alternative methods based on mutual information and on the signal envelope, with the aim of getting an improved estimation of the temporal and spatial 4D shifts, even in the case of signal phase variations between base and monitor image. We quantify the performances of the proposed methods using synthetic examples, and we also show results of application to a real 4D dataset. From the analysed results, we conclude that the mutual information method gives better results than cross-correlation, but the larger improvements are obtained when computing the envelope of the signal, as it allows well estimating the time shifts in presence of 4D phase variations between base and monitor. Moreover, the results on field data obtained with the envelope-based mutual information method are more closely related to the expected dynamic changes within the reservoir.