水压致裂室内模拟实验的声发射观测

OBSERVATIONS ON THE ACOUSTIC EMISSION IN AN IN-HOUSE HYDROFRACTURING SIMULATION EXPERIMENT

本文介绍了水压致裂室内模拟实验的声发射观测结果,指出了水压致裂的裂缝扩展是一个不连续的过程;微观破裂源与宏观破裂的分布大体一致,都出现在最大水平主应力方向上;线破裂源法向上的声发射辐射强度较大;观测到的辐射信号通常以S波较强;完整岩石的压裂通常都有明显的声发射发生;但声发射强度与破裂压力的对应关系不明显。上述实验的结果可以做为野外实际观测的参考。

This paper presents the observational results of the acoustic emission from an in-house hydrofracturing simulation experiment. It points out that propagation of the hydrofracturing crack is not continuous. Source of microfracturing and the distribution of macroc-cracks coincide generally, they all occur in the orientation of maximum horizontal principal stress. Amplitude of acoustic emission is bigger along a direction normal to the linear fracturing source. The amplitude of S wave is bigger in the observed signals. Obvious acoustic emission usually occurs at a fracturing of an integral rock, However, the amplitude of acoustic emission has not on obvious relation to fracturing pressure. These experimental results may be used as a reference to the actual field observations.