Development and application of iterative facies-constrained seismic inversion

To improve the accuracy of inversion results, geological facies distributions are considered as additional constraints in the inversion process. However, the geological facies itself also has its own uncertainty. In this paper, the initial sedimentary facies maps are obtained by integrated geological analysis from well data, seismic attributes, and deterministic inversion results. Then the first iteration of facies-constrained seismic inversion is performed. According to that result and other data such as geological information, the facies distribution can be updated using cluster analysis. The next round of facies-constrained inversion can then be performed. This process will be repeated until the facies inconsistency or error before and after the inversion is minimized. It forms a new iterative facies-constrained seismic inversion technique. Compared with conventional facies-constrained seismic inversion, the proposed method not only can reduces the non-uniqueness of seismic inversion results but also can improves its resolution. As a consequence, the sedimentary facies will be more consistent with the geology. A practical application demonstrated that the superposition relationship of sand bodies could be better delineated based on this new seismic inversion technique. The result highly increases the understanding of reservoir connectivity and its accuracy, which can be used to guide further development.