Abstract: Tahe field is characterized by strong heterogeneity of the Ordovician carbonate reservoirs, complicated oil-gas-water relationship and complex reservoir type. The 3D geologic modeling has shown quantitative characterization of the pore, vug and fracture of the weathering crust within 300 m in the reservoir. But with in-depth development of Tahe field, it has been suggested there exist vertical dense limestone segments that play a role of barriers among the fractured-vuggy carbonate reservoirs. This paper conducts the correlation researches on well dense segment and interwell dense barriers by means of related geologic cognition and well logging, seismic and well performance data, by which the 3D model for dense limestone barrier is developed. This model can be helpful for evaluating the lateral connectivity of reservoirs and selecting the waterflood pattern, water shutoff measure and blocking interval.

Key words: fractured-vuggy reservoir, dense barrier, logging identification, reservoir modeling