Enhanced Heavy Oil Reservoir Characterization by Constrained Inversion of Land Controlled Source EM Data

In this study a land surface CSEM dataset acquired over a heavy oil reservoir was inverted for resistivity structure through 3D CSEM constrained inversion. Unconstrained and constrained results proved good match with available well data. High/low saturated sands respond differently in terms of resistivity signature, therefore the recovered model from CSEM measurement can be used for prospect ranking/de-risking prior to drilling campaigns. 3D constrained inversion provides evident enhancement in model resolution, both laterally and vertically. This shows that surface CSEM, when complemented with the necessary apriori information and ancillary G&G data, is capable of recovering the variations of resistivity within the formation with a resolution comparable to the distribution of the well logs in the area. The technology can also be applied for monitoring applications, using surface CSEM surveys to complement the more localized measurements performed at reservoir depth, such as resistivity logging, cross-well EM, Surface-to-Borehole EM, etc.