缝网压裂技术在近期非常规储层改造中取得重要进展,已经得到形成裂缝网络的力学控制条件.针对双重介质致密油藏、采用EQ-LGR方法描述压裂裂缝网络系统建立离散正交缝网数值模型;忽略致密油藏中吸附作用、高速非达西渗流影响和裂缝导流能力变化,模拟不同地层渗透率下实施缝网压裂和常规压裂时的增产效果和裂缝网络对压裂产能的贡献.缝网压裂的增产效果始终高于常规压裂,且致密油藏中缝网压裂后单井产量增加更显著;而相对高渗储层实施缝网压裂与常规压裂的效果较为接近.考虑实施常规压裂更能降低成本和风险,首次明确提出实施缝网压裂的临界渗透率为1.00× 10-3 μm2.研究成果不仅为优化压裂裂缝参数提供了手段,也为优选压裂工艺提供了理论依据.
Network fracturing technique has made great progress recently in unconventional reservoir stimulation, and the mechanic controlling conditions of the fracture network have been obtained. In the light of the dual-media tight oil reservoir, the fracture network system is characterized by EQ-LGR method, and moreover the numerical model of discrete orthogonal fracture network is established; by ignoring the adsorption, influence of high-velocity non- Darcy flow and fracture conductivity change in the ted for the network and conventional fracturings in tight oil reservoir, the production simulation effects and are simula- the reservoir with different permeabilities and so is the contribution of the fracture network to the fracturing productivity. The simulated effects of the network fraeturing are always higher than those of the conventional one, and furthermore the simulation of the individual well is especially higher for the tight oil reservoir; while for the relative higher permeability reservoir, the effects of the two methods stated above are rather closer. In the consideration of the conventional fracturing can reduce the cost and risk to a great deal, the critical permeability limitation for the implementation of the network fracturing is determined initially and clearly to be 1.00× 10^-3μm^2. The study achievements have not only provided the means of optimizing the fracture parameters of the fracturings, hut also presented the theoretical basis for tt~e optimization of the fracturing technology.