岩石动态损伤模拟实验装置的研制

Development of experimental apparatus of simulation for rocks dynamic damage

基于爆燃压裂技术原理,研制了岩石动态损伤模拟实验装置。该装置用一重物自由落体撞击岩心夹持器的内活动柱塞,压缩岩心模拟井眼内的流体,产生动态压强作用于岩心模拟井眼壁面,以模拟油井爆燃压裂时爆燃药爆燃所产生的动态压强对井眼附近油层的影响。根据动量和能量守衡原理,建立了岩石动态损伤峰值压力和加压速率计算模型,并通过实验验证了计算模型的准确性,增压值和加压速率的计算值与实验结果的平均相对误差分别为2.56%和4.04%。该装置的研制为动载下的岩石力学特性研究提供了定量研究手段。

Based on the principle of exploding in the hydraulic fracture front, experimental apparatus on dynamic damage of rocks was developed. A failing weight was employed in the apparatus to impact the inner piston at the top of the testing cell, and the fluid was compressed by the impacted piston and a dynamic pressure intensity was transmitted to the borehole of the testing rocks. The effects of the dynamic pressure intensity generated by propellant combustion on the near-wellbore scale were stimulated. According to the laws of momentum conservation and energy conservation, the calculation models of the peak pressure and the pressurization rates coming from the dynamic damage of rocks were built. The precision of calculation models was proved, and the average relative deviations between the calculation results and experimental results of the pressurization value and the pressurization rates are 2. 56% and 4.04% respectively. The developed apparatus provides a quantitative analysis instrument to study the rock mechanical characteristics.