A Research On Volcanic Lithofacies And Characteristics Of Volcanic Reservoir Of Carboniferous, In The Northwest Edge Of Junggar Basin

The paper takes the Carboniferous volcanic reservoir of the northwest edge in Junggar Basin as the research object. Volcanic eruption pattern, petrology and petrological characteristics, lithofacies and spatial and distributions, The type and characteristics of reservoir space,the relationship of volcanic rock lithofacies and Reservoir ,and parameters controlling the reservoir quality are studied in this paper. Based upon the description and observation of drilling hole, identification of blue epoxy resin-impregnated thin section, individual well facies analysis stratigraphic classification and comparison, seismic interpretation data. The prospecting high quality reservoir area is being assessed, based on the above integrated research work.Through this study, 6 new congitions and conclusions are acquired: 1.Volcanic eruption model is mainly crack eruption controlled by faults, central eruption is secondely in the northwest edge of Junggar Basin. 2. The majority of the colcanic lithology is intermediate rock, secondly is basite rock. the volcanicalastic and lava are the majority type of rock. 3. There are mainly 4 kinds of facies in this area: volcanic channel facies, eruption facies, overflow facies, volcanic sedimentary facies. eruption facies and overflow facies is the mainly facies. 4. The facies belt is controlled by KE-BAI fault and HONG-CHE fault strike direction is north-south. 5.primary space, induced space and compound space are the main types of the reservoir space in northwest edge area. Primary space contains air cavity and residual pore in amygdaloid,intergranular pore and contract seam. Induced space contains dissolved pore in feldspar and quartz and structure seam. Compound space contains pore-seam and seam-pore. 6.The reservoir’s capability basically depend an the lithology and facies of volcanic, tectonic movement and fault’affection, the influence of diagenesis and fluid medium and weathering. 7. The prediction of good volcanic reservoir: The best volcanic reservoir of northwest edge is the KE-BAI fault’s and HONG-CHE fault’s formations.