关键词: 岩溶缝洞体系, 碳酸盐岩储层, 成藏条件, 奥陶系, 塔里木盆地北部

Abstract: The integral study of petroleum geology,geophysics and oil-gas exploration indicates that Tahe Oilfield formed on the basis of long-developed paleo-uplift is a large scale one which consists of karst-fracture reservoirs of Lower Ordovician carbonate rock.The carbonate rock reservoir developed on the environment of open-limited sea platform presents the features of karst-fracture reservoir of lower matrix porority,and permeability and stronge heterogeneity controlled by tectonisim and karstification because the reservoir underwent multi-stages superimposed reformation of tectonisim,karstification and diagenesis at late time.The karst-fracture reservoir of Tahe Oilfield is mainly distributed in the center platform of paleo-buried hill and the southern slope,and in the scope of 200 metres under uncomformity interface of weathering crust.A complex and multi-episodes oil-gas accumulating dynamic system in Tahe petroleum area is composed of paleo-buried hill,karst-fractures,faults,surface of uncomformity and conduit.

Key words: karst-fractures system, carbonate rock reservoir, oil-gas accumulating condition, Lower Ordovician, northern Tarim Basin