Abstract:

The carbonate reservoirs in the Tarim basin are characterized by old age,deep burial,various types and complex genesis.Through analyzing the characteristics and genetic mechanisms of karst reservoirs,reef-bank reservoirs,dolomite reservoirs and fractured reservoirs,this paper discusses the main factors controlling reservoir heterogeneities.It concludes that favorable sedimentary facies was the material base for forming excellent reservoirs,sequence boundaries controlled the early formation of pores,paleouplifts and tectonic movements determined the development and preservation of the karst and reef-bank reservoirs,and later modification by burial and denudation was critical to the formation of quality reservoirs.On the basis of controlling factor analysis,the paper further suggests that the karst reservoirs were mainly controlled by tectonic uplifting,palaeo-geomorphology and palaeo-drainage system,the reef-bank reservoirs were controlled by the edge high energy facies on platform edge,the dolomite reservoirs mainly developed under the unconformity,and the fracture reservoirs were the products of multiphase tectonic movements.Combining with macro geological background,the fractured karst reservoirs,reef-bank reservoirs,and inner dolomite reservoirs are recognized as favorable exploration targets in Tarim basin.

Key words: karst, reef-bank, dolomite, carbonate rock, reservoir, Tarim Basin