物理-化学耦合作用下泥页岩坍塌周期应用研究

基于泥页岩地层井壁周期性失稳的特点,将泥页岩地层视为孔隙介质进行分析,根据多孔热弹性理论及泥页岩的本构关系,考虑泥页岩地层在温度、孔隙压力、泥页岩水化等因素的耦合作用,建立了耦合数学模型,得出了不同泥浆体系和不同泥浆密度下泥页岩井壁的坍塌周期。在西部巨厚、复杂的泥页岩地层井壁失稳的研究中表明,其应用效果和实际情况吻合较好。

Applied research of collapse cycle of shale in wellbore using a coupled physico-chemical model

The collapse of shale often happens in wellbore of water-sensitive shale formations during drilling. The shale formation was taken as pore medium to be analyzed. In consideration of coupled interaction of thermal diffusion, pore pressure and mud-shale hydration on shale formation, the coupling model for collapse cycle of wellbore was established on the basis of the constitutive relationship of shale and multi-porous thermo-elastic theory. The proper collapse cycle of shale in wellbore can be obtained with the model.