砂岩回弹物理模拟实验

地层剥蚀会造成下伏砂岩的回弹,而砂岩回弹可为油气聚集提供更多的空间。在地质条件下,砂岩回弹受哪些因素的影响,能有多大的回弹量?本文在前人研究的基础上,采用从美国引进的全伺服三轴岩石力学实验装置及正交实验方法,分别对人造砂岩和大庆长垣的实际砂岩进行物理模拟实验,探讨砂体回弹的回弹量及其影响因素。实验结果表明:在岩石弹性范围内,卸载会造成下伏砂体回弹,且回弹量是可观的,可超过1%;岩性是影响砂体回弹的最主要的因素,围压次之;砂体回弹过程与有效上覆压力关系密切,可以用对数模型来描述。

Physical Simulation Experiments of Sandstone Rebounding

All forms of matter have the property of elasticity that can be compressed when the load increases and can spring when the load decreases, so do the porosity rock. The investigation of petroliferous basins over the world showed that one or more erosions had occurred after its reservoirs deposit which means unloading and leads to sandstone spring or interstice expanding so that the pressure fall in the reservoir underneath the erosion surface. The process could offer not only extra spaces for oil and gas accumulation but also the power to pump oil and gas. Based on geological analysis, a physical simulation experiment has been done, and the result of the experiment indicates that the lithology is the uppermost factor controlling the sandstone spring, and the confining pressure takes second place. And a mathematical model has been found between the sandstone spring process and the effective overburden pressure depending on the analysis of the experimental result. A comparison of sandstone-spring quantities between natural cores and artificial cores showed that the former is usually less than 1% and the last is usually more than 1%.