组合水压致裂试验系统装置的研制及应用OA

In order to study combined hydraulic fracturing which is different from single hydrostatic hydraulic fracturing and pulse hydraulic fracturing,an appropriate hydrostatic and pulse hydraulic loading experimental system was developed.The device can realize combined hydraulic loading on the test block,providing a physical basis for studying the effects of pulse pressure amplitude,pulse frequency and relative preload time on the hydraulic crack growth results of the test block in the combined hydraulic loading mode.The device was used to conduct combined hydraulic fracturing tests on rock-like test blocks,and compared with static pressure and pulse hydraulic fracturing tests.The test results show that compared with hydrostatic hydraulic fracturing technology,combined hydraulic fracturing can effectively improve the development of cracks,produce larger crack areas and more crack numbers,and its permeability enhancement effect is better;compared with pulsed hydraulic fracturing technology,combined hydraulic fracturing can shorten the loading period by adjusting the relative preload time,and under low-frequency and low-pressure preload conditions,the combined hydraulic fracturing can produce larger crack areas.