Abstract:

The research on deep-buried volcanic reservoir is an important new field of oil and gas exploration in Songliao Basin. Geochemical and petrological research proves that neutral and acid extrusive volcanic rock is the major type of volcanic rocks in Yingcheng Formation, Xingshan area, compared with that of south part of this basin. In ryolite, the gas pores, dissolved pores caused by efflorescence as well as structural fracture are favorable reservoir spaces. Core analysis shows that relationship between porosity and permeability is different in different areas, so does the heterogeneity. Different volcanic lithologies can be well identified with imaging well logging with conventional logging data, and it's possible to describe and predict porous and fractural reservoir. Lateral resistivity is used to predict the porosity and architecture of fracture, which coincides well with the imaging logging data and core describing. Favorable volcanic facies, efflorescence and structural fracture are three major controlling factors of favorable volcanic reservoir- Under the direction of these major controlling factors, three kinds of volcanic rock body parameters（volcanic thickness, seal thickness and structural curvature）achieved by log restricted seismic inversion, favorable facies, the type of reservoir spaces and physical property of reservoir, volcanic reservoir of Yingcheng Formatioin in the research area can be divided into three types and eight favorable distribution areas of reservoir can be predicted. The results are consistent with drilling and testing data very well, and provide direction for exploration of deep volcanic reservoir.

Key words: volcanic rock, favorable reservoir, controlling factor, distribution prediction, Songliao Basin