不同类型储层支撑裂缝长期导流能力实验研究

Experimental Study on Long-term Flow Conductivity of Fractured Fractures in Different Types of Reservoirs

在油气田压裂作业过程中,对于不同类型岩性储层,支撑剂的嵌入和破碎程度不同,不同程度的嵌入和破碎都会导致裂缝缝宽变窄、导流通道堵塞,使裂缝导流能力降低。为分析不同岩性储层长期导流能力变化趋势以及嵌入和破碎的影响机制,采用FCS-842裂缝导流能力测试系统在模拟地层条件下分别测试了钢板、页岩岩板、中、细砂岩岩板的长期导流能力;并对实验后的各类型岩板和支撑剂进行了微观观察。实验结果表明:各种岩性岩板的导流能力虽大小不同但变化趋势相似,前10 h下降较快,后期趋于稳定略有下降;支撑剂嵌入程度与各岩性岩板的力学性质相关,嵌入程度随闭合压力增加而增加,在低压下嵌入速度较慢;支撑剂和岩板破碎产生的碎屑运移堵塞导流通道会使实验后期导流能力缓慢下降。

In the process of oil and gas field fracturing operation, for different types of lithologic reservoir, the degree of embedding and fragmentation of the support is different, this will lead to narrow gap, conduct channel blockage, so that the fracture conductivity is reduced. In order to analyze the change trend of long-term flow conductivity of different lithologic reservoirs and the influence mechanism of the embedment and fragmentation. The long-term conductivity of steel plate, shale plate, medium sandstone plate, fine sandstone was measured in the simulated reservoir conditions by FCS-842 fracture flow conductivity testing system, and after the experiment, the microscopic observation of the rock plate and the proppant was carried out. The experimental results show that the flow conductivity of all kinds of lithology rock plate is different but the change trend is similar, and the first 10 hours fall relatively fast, and the latter tends to be stable and slightly decreased; The embedding degree of proppant is related to the mechanical properties of the rock plate, and the embedding degree increases with the increase of the closed pressure, low embedding speed in low pressure; The debris migration and blockage conduct channel produced by the proppant and the broken rock plate will make flow conductivity slow decline in the late stage of experiment.