Abstract:

By studying the feature of source rock and reservoir nature on Fengcheng Formation of the Lower Permian in Wuxia, it is suggested that, owing to the influence of volcanic action, not only the fractureair hole reservoir can be formed in rhyotaxitic weak alloying rubble tuff near craters, but also higher bearing source rocks, such as dolomitic tuff and tuffaceous dolomite can be generated in crater facies. Because of this kind of source rocks, a petroleum system of two kinds of reservoirs with one source is formed, in which the reservoirs are the selfgenerating and selfpreserving reservoir of mother rock and the horizontal fractureair hole reservoir (the former is more important). Using the geochemistry index, rock type and authigene, the organic facies' correlation with volcanic construction has been emphatically studied. According to the fact that big volcanic rock reservoirs contacting with source rock in short distance have the feature of nearsource reservoirs and of selfgenerating and selfpreserving reservoirs, we propose that the best way to guide the prospect of volcanic rock reservoir is to sum up the distribution regularity of volcanic rock source and reservoir system from different basins and different volcanic rocks and constructions.

Key words:  Wuxia, Permian, Fencheng Formation, volcanic rock, hydrocarbon generation reservoir system