LABORATORY TEST STUDIES OF WATER-ROCK INTERACTION UNDER HIGH SEEPAGE PRESSURE

A new laboratory equipment called High Pressure Permeability Testing Machine is used in this study. The Static Servo Valve is the main control apparatus. It can make the inlet water pressure of the sample stable when this is no computer control. The sample seepage outlet water pressure value can be controlled by speed control valve. The long time water and rock interaction test under high seepage pressure is then achieved. On the basis of this machine, this paper puts forward the different phase ion concentration studying method of water-rock reaction seepage solution. The penetrability change rule of the sample in different phases can be acquired. In order to study the rock strength characteristics influenced by water and rock reaction, with almost the same conditions, the conventional triaxial experiments under high seepage pressure have been conducted for the samples of passing and not passing by long time water and rock interaction. The effective confining pressure which approaches the sample destroying condition has been proposed to analyze the strength characteristics. In order to contrast the study, this paper also presents the conventional triaxial experiments of satiety water sample under the same actual and effective confining pressure values. On basis of the test results, the studied altered rocks have the similar characteristics under high seepage pressure, normal temperature and pressure. The reaction between altered rock and reservoir water is feebleness, which will not affect the rock mass penetrability and mechanics characteristics.