Classification and Evaluation of a Shale Oil Reservoir in the Qingshankou Formation in the Southern Songliao Basin, NE China

Abstract

The reservoir’s physical properties control the seepage capacity of the shale oil. Developing a method to classify and identify high-quality reservoirs is important to commercial shale oil production. In this study, the Qingshankou Formation shale oil reservoir in the southern Songliao Basin in China was selected. A series of reservoir characterization experiments were conducted to investigate the characteristics of the micropore structure of the reservoir and its influencing factors. A shale reservoir classification evaluation standard was established using fractal theory. It is based on the reservoir micro- and macrocharacteristics. The research results show that the reservoir qualities are controlled by mineral composition, sedimentation, and diagenesis. The larger the pore-throat ratio of the reservoir, the more significant the permeability decrease under compaction. A pore size classification standard based on the shale pore characteristics can be established using fractal theory. There is a coupling relationship between pore size and macroscopic physical properties, which can be used to establish the evaluation standard of the reservoir. Based on the division of hydraulic flow units, the standard can be applied to predict favorable reservoirs.

Keywords

shale reservoir / reservoir classification / pore size distribution / fractal analysis / fractal theory / Songliao Basin / geochemistry / petroleum geology

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