Pore Textures and Its Causes of Volcanic Reservoir in Songliao Basin
YANG Shuang-ling1,LIU Wan-zhu2,YU Shi-quan1,WANG Guo-jun1,HUANG Yu-long21.Daqing Exploration & Development Institute,Daqing,Heilongjiang 163712,China2. College of Earth Sciences,Jilin University,Changchun 130061,China
Rhyolite is the main reservoir volcanic rocks of the Songliao Basin,belonging to calc-alkaline type of subalkaline series,also with medium-high-K.Reservoir space can be classified as primary pore,secondary pore and fissure,and furthermore,as thirteen basic genetic sub-types.The average porosity of volcanic reservoir is in range 3-15 percent,permeability(0.1-5)×10-3μm2,and pore radius ranges 0.05-1 μm.Pore structures can be classified as wide form,less wide form,rather narrow form,narrow form and extremely narrow form. Tectonic movements,weathering erosions and fluid activities are the main geologic factors that influence and control the development and evolution of reservoir space.