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Interpretative Quality Control of Towed EM Data – Examples from the North Sea
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 73rd EAGE Conference and Exhibition incorporating SPE EUROPEC 2011, May 2011, cp-238-00333
- ISBN: 978-90-73834-12-5
Abstract
In this paper we focus on data and inversion attributes that we have found useful in both the initial Quality Control and subsequent interpretation of Towed EM data from a North Sea field trial. The attributes are examined as part of a three stage Quality Control workflow. First, we examine the measured data: Towed EM data are arranged into distinct shots, and the mean electric field amplitude per shot is an attribute that captures the main trends and anomalies of the measured data. Second, we examine the frequency response functions that result from data processing: we show that phase differences in particular provide a striking pseudo image of the sub-surface. Third, we present inversion results as depth integrated resistivity (transverse resistance) to summarise sub-surface resistivity models. All attributes are mapped easily to source receiver Common Mid-Point Position: plotting each of the attributes in this way enables the inversion results to be compared to the measured data, and data and model quality to be assessed qualitatively. We show that the measured data, response functions and sub-surface resistivity models are in good agreement.