Numerical simulation of rupture process of shale under action of fluid-solid coupling

In order to investigate the rupture process and acoustic emission characteristics of shale under fluid-solid coupling, the numerical simulation of fluid-solid coupling of the Niutitang Formation shale in different bedding angle in the northern part of the Qianbei area was carried out by RFPA2D-Flow numerical software. Studies have shown that due to the influence of the bedding structure, the compressive strength and elastic modulus of shale show obvious anisotropy. The rupture process of shale can be divided into three stages: elasticity, yielding and destruction. With the change of the bedding angle, the shale finally showed three failure modes, namely oblique I, V and flame. Shale with different bedding dips has different evolutionary rules of acoustic emission signals in the process of fracture. For samples with low bedding angles(0°, 15°, 30°), the cumulative AE curve shows a change pattern of “smooth-linear-step-smooth”. The cumulative AE curve of the high-rise dip angle(60°, 75°, 90°) shows a change pattern of “smooth-linear-steep increase”. When α=45°, the cumulative AE curve shows a change pattern of “smooth-linear-boost-gradual-boost”, and its AE count shows two peaks.