The study examines the effect of cement bond breakage in the mechanical behavior of porous weak sandstones in Kazakhstan’s oil fields using one-dimensional compression, triaxial shearing apparatuses, and Discrete Element Method (DEM) numerical simulation. Analogue sandstone materials were prepared by cementing a sand material with similar mineralogy to the real reservoir with the sodium silicate solution. The results of the cemented sandstones were compared to the results of the uncemented sand, disaggregated sandstone and silty sand of similar particle size distribution to understand the effect of the cemented structure. The failure behavior of the material was investigated in the experimental and numerical studies at different confining pressures and it was found that the behavior is mainly controlled by the cement bonds as there is no major change in the particles during the tests. It was found that the plastic yielding condition is mainly associated with the breakage of the cement bonds and this gives rise to volume compression and strain hardening of the material. The DEM results provide further confirmation that the degradation of the specimen stiffness is directly related to the bond breakage initiation and higher confining pressures affect the breakage rate and weaken the effect of the cemented structure, which is compensated by a stronger role for the frictional resistance between sand particles.

该研究使用一维压缩，三轴剪切设备和离散元方法（DEM）数值模拟研究了水泥粘结断裂对哈萨克斯坦油田多孔弱砂岩力学行为的影响。相似的砂岩材料是通过用硅酸钠溶液将具有与真实储层相似的矿物学特征的砂料胶结来制备的。将胶结砂岩的结果与粒径分布相似的未胶结砂，解集砂岩和粉质砂的结果进行比较，以了解胶结结构的效果。在不同的围压下，通过实验和数值研究对材料的破坏行为进行了研究，发现该行为主要受水泥键控制，因为在测试过程中颗粒没有重大变化。发现塑性屈服条件主要与水泥键的断裂有关，这引起材料的体积压缩和应变硬化。DEM结果进一步证实了样品刚度的下降与粘结断裂的开始直接相关，较高的围压会影响断裂速率并削弱胶结结构的作用，这可以通过更强的摩擦阻力来补偿。沙粒。发现塑性屈服条件主要与水泥键的断裂有关，这引起材料的体积压缩和应变硬化。DEM结果进一步证实了样品刚度的下降与粘结断裂的开始直接相关，较高的围压会影响断裂速率并削弱胶结结构的作用，这可以通过更强的摩擦阻力来补偿。沙粒。发现塑性屈服条件主要与水泥键的断裂有关，这引起材料的体积压缩和应变硬化。DEM结果进一步证实了样品刚度的下降与粘结断裂的开始直接相关，较高的围压会影响断裂速率并削弱胶结结构的作用，这可以通过更强的摩擦阻力来补偿。沙粒。