Various irregular fractured-vuggy reservoirs were formed along the large fault-karst belts in the area covered by the Upper Ordovician in Tahe area due to multi-phase tectonic deformations and karstifications of the carbonates.Using fine coherence

amplitude change rate

time slice and other properties of high-precision three-dimensional seismic

outcrops

drilling and production data

this paper first presented a theoretical concept of fault-karst trap

and elaborated its forming mechanism and geologic characteristics in this area.The fault-karst reservoirs can be divided into three types by their shapes and controlling factors:banded

sandwich and tabular reservoirs.According to recent development practices

the fault-karst reservoir is a very special reservoir type in this area.The development effectiveness of different fault-karst carbonate reservoirs is quite dissimilar

with the banded ones being the best in development performance.It is of great significance for the petroleum exploration and development of similar reservoirs in the Tarim Basin.