Prediction and modeling of fractured-vuggy reservoir in block no. 12 of Tahe Oilfield

In block no. 12 of the Tahe Oilfield, the fractured-vuggy reservoirs in Ordovician are featured by deep depth, irregular caves and fractures development and strong heterogeneity, making reservoir prediction difficult. Based on seismic data, the analyses of the variance ratio of seismic amplitude, eigenvalue coherence and trend surface difference are carried out to show the distribution of fractured-vuggy reservoir. Moreover, the inversion technique of seismic well logging is applied to predict the fractured-vuggy reservoirs in block no. 12 of the Tahe Oilfield. The results show that fractured-vuggy reservoirs are widespread in the study area, but worse in the north than the south. Beaded high-amplitude seismic reflections are well-developed, proved by drilling. Based on impedance inversion and fine-coherence analysis models, an idea of modeling fractured-vuggy reservoir by clustering procedure is proposed.