Study on yield increase mechanism and flow conductivity test method for water-fracturing without proppant

At present, water-fracturing is a key stimulated technique in widespread use for low permeability oil-gas filed to gain extremely economic benefit, on the other hand, the process is not suitable for all low permeability reservoirs. Studies on yield increase mechanism and flow conductivity test method for water-fracturing should be deeply conducted. The mechanisms of fracture diverting and slip for water fracturing, influencing factors and influence law of slippage and the forming mechanism of residual space after crack closed are addressed with the finite element method from different aspects: heterogeneity of rock materials, rock mechanics property, deviation of in-situ stress, the angle between the direction of fracture starting and the maximal horizontal principle stress. The preparation method of self-supporting fracture wall surface combination and test method of flow conductivity for water-fracturing are established, which provide the reference means for deep understanding the production increasing mechanism and suitable reservoir conditions of water-fracturing.