Theoretical assessment of 3-D magnetotelluric method for oil and gas exploration: Synthetic examples

•We make some electrical and velocity synthetic models of typical oil-bearing structure.•We compare 2D and 3D MT forwarding and inversion and 2D seismic forwarding results.•3D MT can make up the shortfall of seismic.•We consider 3D MT inversion technique has important potential for oil exploration.

In petroleum explorations, seismic reflection technique has been almost always the preferred method for its high exploration depth and resolution. However, with the development of three dimensional (3D) inversion and interpretation schemes, much potential has been shown in MT method dealing with complex geological structures as in oil and gas exploration. In this study, synthetic geophysical models of petroleum reservoir structures are modeled and utilized to demonstrate that feasibility of 3-D MT technique for hydrocarbon exploration. A series of typical reservoir structure models are constructed and used to generate synthetic MT and seismic data to test the capabilities of 2-D/3-D MT and 2-D seismic inversion techniques. According to the inversion comparison, in addition to correctly retrieve the original forward model, the 3-D MT method also has some advantages over the reflective seismology method, which suffered from the lack of reflection wave and multiple wave problems. With the presented 3-D high resolution MT inversion method, MT techniques should be employed as one of the first choices for petroleum explorations.