关键词: 离散裂缝网络, 裂缝性储层, 天然裂缝, 压裂液滤失, 渗透率张量, 数学模型

Abstract:

Fracturing fluid leak-off in naturally fractured reservoirs has a great impact on fracture geometry and proppant placement. Existing fractured reservoir fracturing fluid loss models all simplified natural fractures，considering that natural fractures cut evenly on the matrix，which does not truly reflect the effect of heterogeneity of fracture distribution on fracturing fluid loss effects. Based on reservoir fracture statistics and by applying probability and statistics stochastic theory，Monte-Carlo and other methods，the two-dimensional discrete fracture network model of the reservoir was established. And on this basis，by translating fractured media into homogeneous anisotropic continuum medium，we established fracturing fluid filtration model of fractured reservoir. The results show that along the direction of fracture，fracturing fluid filtration rates vary widely due to the distribution of natural fractures and its positional relationship with hydraulic fracture. If natural fractures connects with hydraulic fracture，the fracturing fluid loss occurs mainly in the connected department. This paper simulates the three artificial connections filtration，which account for 45% loss in total. Therefore，it is recommended to seal natural fractures in fractured reservoir fracturing.

Key words: discrete fracture network, fractured reservoir, natural fractures, fracturing fluid loss, permeability tensor theory,
mathematical model