Natural gas of volcanic gas reservoirs in China is rich in resources, and its exploration and development is great potential, but the study of the volcanic gas reservoir is a brand new field, there are a lot of difficulties in this study field. Due to the key problem of describing the formation framework of the volcanic gas reservoir hierarchically, this paper break the study method of sedimentary reservoir, take XS 21 block volcanic gas reservoir in XS Gas Field, north Songliao Basin as the example, use outcrop??core?? logging??seismic data and so on, according to the idea of "the control of magma source??, present the "Volcanic edifice -
volcanic facies- effective accumulating and filtrating body?? volcanic formation hierarchical describing plan. Stressly, illustrate the Volcanic edifice identify and classify idea of confirm magma source-confirm surface-confirm body, and expound the concrete way to confirm volcanic crater by seismic section??seismic attribution and microtectonics, confirm surface of the volcanic edifice by outcrop??logging and seismic data, confirm body by 3D seismics. Though this idea and way, we identify and dissect the volcanic edifices in XS 21 block, and describe them quantitatively. This study is the base of the volcanic reservoir description and prediction, at the same time, it create a new way to study the volcanic reservoir more scientific than before.