Acoustic Impedance Contrast Inversion with Multiplicative Regularization

Model-based acoustic impedance inversion is an important step during the seismic data process routine for its relatively high resolution. From the point of view of inversion result, the purpose of this inversion process is to recover the relative acoustic impedance (RAI), which is the difference between the real acoustic impedance and the initial smooth guess. To illustrate this difference distinctly, in this abstract, we introduce the acoustic impedance contrast function (CAI) as the new model parameter. It is defined as the ratio of the RAI to the smooth background acoustic impedance. The CAI is a dimensionless quantity and it associates the absolute acoustic impedance (AAI) with the RAI and the smooth background together. Then, the relative reflectivity and relative seismic record can be represented by this new parameter. Further, the objective function that relates the CAI to the relative seismic record is constructed, and it is constrained by the multiplicative regularization for inversion stability. When the CAI is obtained, the RAI and AAI can also be calculated. Well log data test and field data application demonstrate the effectiveness and superiority of the method.