围压-孔隙压力作用下碳酸盐岩力学特性实验

Experimental study on mechanical property of carbonate under the effect of confining pressure and pore pressure

对塔河碳酸盐岩岩心进行了一系列围压、孔隙压力条件下的三轴压缩测试,分析结果发现:1低围压时,碳酸盐岩石表现出很强的脆性,抗压强度低;高围压时,碳酸盐岩石表现出强塑性,且可能出现塑性硬化。2碳酸盐岩的弹性模量随围压的增大而增大,抗压强度随孔隙压力的增大而降低。3孔隙压力增大,碳酸盐岩的内聚力增大,内摩擦角降低。

The triaxial compression tests of the carbonate cores from Tahe Oilfield under the effect of different confining pressuresand pore pressures are carried out,and it is shown that:( 1) the carbonate presents strong brittleness and low compressive strength under low confining pressure,while it presents strong plasticity and plastic hardening may occur under high confining pressure;( 2) Young's modulus of the carbonate increases with the increase of confining pressure,and its compressive strength decreases with the increase of pore pressure;( 3) the cohesion of the carbonate increases and its internal frictional angle decrease with the increase of pore pressure.