Abstract:

Deep volcanic reservoirs of Songliao basin have mainly been found in Huoshiling and Yingcheng Fms..The eruptive and overflow facies have better reservoir capacity, commonly with the porosity of 6.3%～10.8% and permeability of about 0.55×10^-3 ～122.0×10^-3 μm².The reservoir capacity of volcanic rocks has largely been affected by tectonism,solution and fluid activity.There are lots of fractures in volcanic rock due to tectonic activity during the volcanic-fault-depression period in Songliao basin,which would enhance the reservoir capacity.The eruptive tuffaceous volcanic has been mainly changed by leaching, and become loose and porous,with the porosity to be increased to over 15%.Fluid flow has double effects on reservoir capacity of volcanic rock, reservoir capacity would be reduced by cementation and filling of new minerals,but on the other hand, porosity would be increased by alteration and solution.These should,therefore, be studied separately by stages and periods.

Key words: volcanic rock, reservoir, volcanic facies, affecting factors, Songliao basin