Geostatistical inversion in thin limestone reservoir of low porosity and low permeability: The case study in Da'anzhai member in the eastern Sichuan Basin

Abstract

The prediction of thin limestone reservoir is an international problem in seismic exploration. The limestone reservoir of Da'anzhai member in the eastern Sichuan Basin features super tightness, strong heterogeneity and thin layers. Based on post-stack deterministic Constrained Sparse Spike Inversion, this paper applies geostatistical inversion to predict the thin limestone reservoir of Da'anzhai member. The geostatistical inversion method can effectively integrate geological, well logging and seismic data, taking advantage of the higher vertical resolution of well logging data and higher lateral resolution of seismic data, describing the subtle changes in the reservoir more accurately, thus it works well in identifying thin limestone reservoir with strong heterogeneity. Furthermore, the formation porosity is achieved by cosimulation, and the predicted results match well drilling result well.