The Characteristics And Controlling Factors Of Carboniferous Volcanic Reservoir In Ludong Area Of Junggar Basin

The Ludong area located in the eastern Luliang uplift, which is in the Northeast part of Junggar basin. High gas flows have been acquired at many gas wells in the carboniferous volcanic reservoirs in this area, which is showing a good exploration prospect of the carboniferous volcanic gas reservoirs in Longdong area. However, the complexity of volcanic lithology, the diversity of its controlling factors and the limitations of the research methods of the volcanic reservoirs at home and abroad hindered the pace of further exploration.On the basis of previous studies, under the guidance of advanced theories and methods such as sequence stratigraphy, reservoir geology, Petroleum Geology and geochemistry, through a large number of relevant exploration data and field observation, microscope observation and statistics of thin section and chemical total analysis of rocks, the essay analyze the characteristic of the volcanic lithology, volcanic faces, the reservoir pore space types, based on this, through scanning electron microscope(SEM)and physical properties, physical property of the reservoir and the digenesis of the volcanic rocks were analyzed.Based on these studies above, the Controlling Factors of the favorable reservoir were analyzed, and the Classification and Evaluation of the reservoir were also be studied.The results show that the area includes6major categories of21species of rock types: volcanic lava, pyroclastic, welded pyroclastic, volcanic-sedimentary rocks, sub-volcanic rocks and hypabyssal intrusive rocks. the mainly faces is overflow faces, the second is volcanic eruption faces, the third is volcanic conduit faces. The main reservoir space are different kinds of secondary pores and fractures, the best combination of storage space are the corrosion holes-fractures. The mainly diagenesis of the volcanic rock included weathering leaching, dissolution, alteration, and tectonic movement. The improving of the performance of the reservoir is largely due to weathering leaching, dissolution, lithofacies and lithologic.The reservoirs were divided into4sections, the first three have the conditions of forming commercial reservoir, the forth didn’t.