Cooperative inversion of seismic and magnetotelluric data in complex areas: A workflow

Abstract

Joint inversion or cooperative inversion of different geophysical data has the potential of providing more accurate estimate of subsurface rock properties. We present a cooperative inversion approach for acoustic impedance using seismic and magnetotelluric data. In this approach, the magnetotelluric data, sensitive to the resistivity of rocks are used to get the large scale background spatial trends of the acoustic impedance model. The magnetotelluric data also provide complementary information to seismic in complex areas such as subbasalt, subbsalt and overthrust belts where the propagation of seismic wave is difficult. On the other hand, seismic data are used to get the small-scale features in the recovered model. The connections between resistivity, density and velocity are obtained from petrophysical relationships derived from bore-hole data. Additional information such as structural coupling obtained from geological information can also be added during the inversion process. We present an application of this technique to synthetic data. The synthetic example demonstrates how an improved result is achieved at step of of our cooperative inversion process. In particular we show how artifacts are progressively eliminated with new cycles of the cooperative inversion workflow.