大尺度水压致裂模拟实验

THE GREAT SCALE ROCK EXPERIMENT SIMULATING HYDRAULIC FRACTURING

本文介绍了在大型双向加载机上进行的大尺度水压致裂模拟实验结果。样品尺寸为４０ｃｍ×４０ｃｍ×２０ｃｍ，辉长岩、大理岩各４块。实验结果表明，从注入压力－时间曲线上可以量出稳定的初破裂压力、重张压力、封闭压力。封闭压力、重张压力不仅与应力条件有关，而且和对应裂缝几何形态的弹性恢复能力有关，从而和岩石的弹性常数、裂缝尺度有关。初裂缝是沿着最大水平主应力方向的垂直缝。峰值注入压力不是孔壁张开压力。

This paper present the results of great scale hydraulic fracturing simulant experiment to be made in the large-scale two-way compressor.The scale of rock samples is 40 cm×40 cm×20 cm.The samples of gabbro and marble is four piece respectively.The results of experiment show that: We can measurement stable first fracturing pressure,again open pressure,and close pressure.The close pressure and again open pressure are not only relative with stress condition,and are relative with elastic recover ability of corresponding crack geometry shape.The beginning of crack is vertical along the orientation of maximum horizontal principal stress.The maximum injecting pressure isn't the open pressure of hole wall,the open pressure of hole wall is usually small than the maximum injecting pressure.