流体饱和下高孔隙率储油砂岩力学特性及本构模型

通过对其力学实验结果的分析,以两种破坏理论对油及水饱和下大孔隙率储油砂岩的破坏特征进行了解释,并应用塑性力学的盖帽模型建立了油及水饱和下大孔隙率储油砂岩的本构模型,并应用非线性有限元法进行了数值试验,结果表明,该文提出的模型与实验资料吻合良好,且能较好地模拟大孔隙率砂岩的几种破坏机理及模拟注水采油引起的砂岩附加沉降.

MECHNICAL BEHAVIOUR OF A LARGE POROUS SANDSTONE WITH SATURATIONG FLUID IN OIL RESERVOIR AND ITS CONSTITUTIVE MODEL

A different mechanics behaviour and a different failure style were observed of the large porous sanstone in oil reservoir with diffrent confining pressure and diffrent saturating fluids(e.g.oil or water).Laboratory test demonstrated that a critical value of confining pressure was proved to be exist,when the confining pressure is increased,the mainly pressure-shear failure can be changed into slough failure.In the paper,the two sorts failure throries are used to explain failure types of large porous sandstone with water saturation and oil saturation respectively through analisis on the results of laboratory test on large porous sandstone.A constitutive model of large porous sandstone is established using the Cap model of plasticity and 3-dimensional nonlinear FEM was used to test the model.The nimerical results show that the laboratory tests are good in agreement with the mumerical simulation using the model of the paper,and the failure mechanisms and the additional subsidence of large porous sandstone from oil exploitation by hydraulic grouting are also simulated well.