Analysis On Affecting Factor Of Volcanic Reservoir In Yc1 Of Xujiaweizi Fault Depression, Songliao Basin

Volcanic reservoir in the yc1 of Xujiaweizi fault depression play an important role in the oil and gas exploration in Songliao basin. Petrological and geochemical research proves that acid volcanic rock is the major rock in the formation of yc1, then the intermediate rock, and there is little basite. Different volcanic lithologies can be well identified by the method of log cross plot, cluster analysis and imaging well logging. Facies sequence of volcanic rocks is predominantly controlled by Lithotypes, accoding to which 5 volcanic facies and 15 volcanic sub-facies are defined. the explosive facies and the effusive facies is the most important one. The pattern feature of plane phasing is confirmed by the method of well logging, seism and geology mode of facies. it is obviously controled by large-scale fracture belt. The type of accumulating spaces is classified by analysis to thin section. In the diagenesis, dissolution, tectonic action and weathering is commonly the main factor in the development and evolution of accumulating spaces in lava and volcaniclastic rock. It is obtained by the statistics to core data that physical property of lava and volcaniclastic rock is similar, and the physical property of the facies near crater is better than that far away from it, from which we can draw the conclusion that physical property of reservoir is obviously controlled by Volcanic edifice. We analysed the spatial distribution feature of volcanic reservoir by the method of model building. It was obtained by the research to structure and property of the model: Affected by tectonic action, fracture was well developed about the fault, in which the physical property is better than others; Affected by weathering and eluviation, the physical property in high place is well in its entirety; the volcanic rocks thickness of yc1 has no relationship with the physical property.Tectonic movement is the fundamental one of all the affecting factor.