A 3D finite-element modelling investigation into optimal survey parameters and direct imaging for marine controlled-source electromagnetic surveys

摘要

Relatively little is known about marine controlled-source electromagneticsurveys (MCSEM) used to detect hydrocarbon reservoirs. Typical MCSEM require theuse of inversion to generate a model of the subsurface. We utilize a 3D finite-elementforward model to simulate a MCSEM survey. With the results we were able todetermine the strengths and weaknesses of each transmitter and receiver configurationthat would best detect a shallow hydrocarbon target. Careful selection of the correctconfiguration is important as we have found that incorrect transmitter orientation, offsetand receiver measurement component can yield misleading results. Using the idealconfiguration we were able to directly image the hydrocarbon target without the use ofinversion modeling. The direct image is able to show the hydrocarbon target's shapeand edges without any ambiguity. The direct image of the target can potentially be usedto refine 3D inversion modeling, or be used in conjunction with seismic profiles to refineseismic picks.