Hydraulic pressure is one of the important factors influencing the stability of well rock. In this paper, the sleeve typed shale rock specimens were used to laboratory simulate the long-term stability of shale rock wellbore under hydro-mechanical coupled condition. Based on the analysis of triaxial tests data, the strength characteristic of the saturated shale specimens was first studied. The results show that the strength presents an exponential decreasing trend with increasing hydraulic pressure; 5 MPa hydraulic pressure resulted in the axial compressive strength declined by around 12.20% and about 17.78% fell under the hydraulic pressure of 10 MPa. The creep behavior of the shale was also analyzed in detail. It was found that 60% of the triaxial compression strength can easily lead to rupture of specimen under hydraulic pressure of 5 MPa, while more than 73% of the triaxial compression strength is needed under the same confining pressure without hydraulic pressure. The hydraulic pressure as well as its action time obviously affects the wellbore failure characteristics, which may lead to the damage area appearing pulverized, seriously reducing its mechanical properties. A new viscoelastic-plastic creep damage model was proposed to describe the creep behavior of shale rock, and it was found that the creep model can be used to predict the long-term stability of the wellbore.

液压是影响井壁稳定性的重要因素之一。本文采用套筒型页岩岩样，对水力耦合条件下的页岩岩心长期稳定性进行了实验室模拟。在分析三轴试验数据的基础上，首先研究了饱和页岩试件的强度特性。结果表明，随着液压的增加，强度呈现出指数下降的趋势。5 MPa液压导致轴向压缩强度在10 MPa液压下下降了约12.20％，下降了约17.78％。还详细分析了页岩的蠕变行为。结果发现，在5 MPa的液压压力下，三轴抗压强度的60％容易导致试样破裂，在没有液压的情况下，在相同的围压下，三轴抗压强度需要达到73％以上。液压及其作用时间显然会影响井筒的破坏特性，这可能导致损坏区域显得被粉碎，从而严重降低其机械性能。提出了一种新的粘弹塑性蠕变损伤模型来描述页岩的蠕变行为，发现该蠕变模型可用于预测井眼的长期稳定性。严重降低其机械性能。提出了一种新的粘弹塑性蠕变损伤模型来描述页岩的蠕变行为，发现该蠕变模型可用于预测井眼的长期稳定性。严重降低其机械性能。提出了一种新的粘弹塑性蠕变损伤模型来描述页岩的蠕变行为，发现该蠕变模型可用于预测井眼的长期稳定性。