考虑孔隙压力影响的碳酸盐岩裂缝成因模式研究

The Fracture Genetic Modes of Carbonate Considering the Effect of Pore Pressure

通过三轴压缩实验研究了在不同围压和孔隙压力下碳酸盐岩破裂方式及裂缝分布形态。在设定的加载方式下,针对某异常高压油田碳酸盐岩实验结果表明:岩石在压缩导致破裂的过程中,破裂方式主要与有效应力有关;随着有效围压的增大,岩石逐渐由脆性变形转化为塑性变形。对三轴压缩实验后的岩心磨制了薄片,从微观上分析裂缝成因模式。随着有效围压的增大,裂缝类型分别为劈裂面、高角度缝、共轭剪切缝、高密度网状缝。

By triaxial compression test to study the fracture pattern of carbonate and the distribution of fractures under different confining pressures and pore pressures. Under the given loading conditions, the experimental results aimed at a carboniferous reservoir carbonate rock show that： on the course of rock rupture caused by compression, rupture mode is mainly related to the effective stress. With the increase of effective confining pressure, rocks gradual- ly transform from brittle deformation into plastic deformation. Cores taken after the triaxial compression test are grin- ded into thin section. Analysis on the cracks genetic model indicates that： with the increase of effective confining pressure, fracture types are separately high-angle fracture, conjugate shear fractures, high-density netted fractures.