Analysis of Reservoir Fracture Complexity based on Core Brittleness Characteristics

10.6919/ICJE.202205_8(5).0019

Zilin Zhang

Reservoir Core ； Brittle Characteristics ； Total Stress-strain Curve ； Brittleness Evaluation Model

International Core Journal of Engineering

8卷5期（2022 / 05 / 01）

146 - 150

英文

The brittleness index characteristics of reservoir cores are highly related to the post-pressure effect of tight oil, and the research on the influence law of brittleness on fracture complexity of tight reservoirs is significant for process optimization and post-pressure effect evaluation. The brittleness evaluation model of reservoir core based on full stress-strain curve is proposed by comprehensively considering the brittleness characteristics of the whole process of rock damage, i.e. pre-peak and post-peak stages; the accuracy of this model is verified by using uniaxial and triaxial stress-strain curves of rocks with different lithologies and existing brittleness evaluation models. The brittleness evaluation model can comprehensively evaluate the brittleness characteristics exhibited by the whole process of core destruction, and is more sensitive to the brittleness changes of rocks under different surrounding pressures of different lithologies than the traditional brittleness evaluation model; the strength parameters and elastic modulus of cores under different surrounding pressures are negatively correlated with the brittleness index.

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