The practice of oilfield development promotes the development theory, and the breakthrough of development theory brings about the revolution of development technology. Using horizontal wells and volume fracturing technology, volume fracturing has been applied in unconventional reservoir, and the formation mechanism of complex fracture network will bring innovation to development technology. At present, the research on the formation mechanism mainly focuses on theoretical research, experimental research, and numerical simulation. Theoretically, the mechanical model of the intersection of HF and NF is established, and some judgment criteria are put forward. Activation of NF by HF is a necessary condition for the formation of complex fracture networks; the activation conditions of NF are verified by true triaxial experiment in terms of horizontal stress difference, approximation angle, and fracturing fluid viscosity; finite element method, finite difference method, boundary element method, and discontinuous displacement method have their own advantages and disadvantages on simulation. Using digital speckle correlation technique, the authors explained the mechanism of shear action on the formation of fracture network, established a macro-meso two-scale non-uniform damage constitutive model, and formed a computing method for dynamic expansion of fractured network in tight reservoir. A field well example is calculated using this method.

中文翻译：

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非常规油藏复杂裂缝网络形成机理研究进展

油田开发实践促进了开发理论的发展，开发理论的突破带来了开发技术的革命。利用水平井和体积压裂技术，在非常规油藏中进行了体积压裂，复杂裂缝网络的形成机理将为开发技术带来创新。目前，对形成机理的研究主要集中在理论研究，实验研究和数值模拟上。从理论上讲，建立了HF与NF相交的力学模型，并提出了一些判断标准。HF激活NF是形成复杂断裂网络的必要条件。通过真实的三轴实验，通过水平应力差，近似角和压裂液黏度验证了NF的活化条件。有限元法，有限差分法，边界元法和不连续位移法在模拟上各有优缺点。利用数字散斑相关技术，解释了剪切作用对裂缝网络形成的机理，建立了宏观-介观的两尺度非均匀损伤本构模型，形成了致密油藏裂缝网络动态扩展的计算方法。 。使用此方法可以计算出一个现场井实例。不连续位移法和非连续位移法在仿真上各有优缺点。利用数字散斑相关技术，解释了剪切作用对裂缝网络形成的机理，建立了宏观-介观的两尺度非均匀损伤本构模型，形成了致密油藏裂缝网络动态扩展的计算方法。 。使用此方法可以计算出一个现场井实例。不连续位移法和非连续位移法在仿真上各有优缺点。利用数字散斑相关技术，解释了剪切作用对裂缝网络形成的机理，建立了宏观-介观的两尺度非均匀损伤本构模型，形成了致密油藏裂缝网络动态扩展的计算方法。 。使用此方法可以计算出一个现场井实例。