Abstract Multiple cluster hydraulic fracturing is widely used in the development of shale reservoir. The morphology of multiple fractures propagating from multiple cluster is complex due to the stress shadow effect. The design and operation of multiple cluster hydraulic fracturing in horizontal wells require adequate knowledge of the effect of different factors, including rock properties, in-situ stresses and fluid properties on the fracture morphology. In this paper, lattice simulation, a new particle based computational method was used to investigate the multiple cluster hydraulic fracturing in shale. The results showed that stress anisotropy and cluster spacing play an important role on geometry of the propagating fracture. The middle hydraulic fracture is restricted to propagate when cluster spacing is decreased. Simultaneous, two-step and sequential fracturing scenarios in a single horizontal well were simulated. The simultaneous and sequential fracturing showed to mainly affect the fracture propagation morphology with little effect on fracture length, while the middle fracture is shorter than its two side fractures in two-step fracturing. In two horizontal models, the simultaneous and sequential fractures showed similar morphology during multiple cluster hydraulic fracturing. In term of stimulated reservoir volume (SRV), zipper fracturing showed the largest SRV during multiple cluster hydraulic fracturing in two horizontal wells.

中文翻译：

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基于格子模型的水平井多丛式水力压裂应力影数值模拟

摘要 多丛式水力压裂在页岩油藏开发中得到广泛应用。由于应力阴影效应，多簇扩展的多条裂缝形态复杂。水平井多丛式水力压裂的设计和操作需要充分了解不同因素的影响，包括岩石性质、地应力和流体性质对裂缝形态的影响。在本文中，晶格模拟是一种新的基于粒子的计算方法，用于研究页岩中的多簇水力压裂。结果表明，应力各向异性和簇间距对扩展裂缝的几何形状起着重要作用。当簇间距减小时，中部水力裂缝的扩展受到限制。同时，模拟了单个水平井中的两步和顺序压裂方案。同时压裂和序贯压裂主要影响裂缝扩展形态，对裂缝长度影响不大，两步压裂中缝短于两侧缝。在两个水平模型中，在多簇水力压裂过程中，同时裂缝和顺序裂缝表现出相似的形态。就增产储层体积（SRV）而言，拉链压裂在两口水平井的多丛式水力压裂过程中表现出最大的SRV。而在两步压裂中，中间裂缝短于两侧裂缝。在两个水平模型中，在多簇水力压裂过程中，同时裂缝和顺序裂缝表现出相似的形态。就增产储层体积（SRV）而言，拉链压裂在两口水平井的多丛式水力压裂过程中表现出最大的SRV。而在两步压裂中，中间裂缝短于两侧裂缝。在两个水平模型中，在多簇水力压裂过程中，同时裂缝和顺序裂缝表现出相似的形态。就增产储层体积（SRV）而言，拉链压裂在两口水平井的多丛式水力压裂过程中表现出最大的SRV。