Abstract: Based on the geological characteristics and the exploitation rule of Tahe fractured carbonate reservoir, a set of indoor experimental devices that can be used to simulate single-well water injection for oil displacement is established. The main mechanism of the devices is to add energy and replace gravity. Closing to the actual conditions of the reservoir, water injection and gas injection are carried out to test the correlation between the multiple of pore volume and the recovery degree and stress. The results show that exploitation with natural energy is on a low level. And the injection after two rounds becomes invalid basically. In addition, after several rounds of water stability in the exploitation, gas injection in the later rounds of exploitation has a good recovery results, especially in the former three rounds. After gas injection there is an increase of 27.4 percent in the degree of recovery.