Reduced order model for simultaneous growth of multiple closely-spaced radial hydraulic fractures
Reduced order model for simultaneous growth of multiple closely-spaced radial hydraulic fractures
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DOI：
10.1016/j.jcp.2018.09.004
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Cheng Cheng-Cheng;A. Bunger
中科院分区：
文献类型：
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作者：
Cheng Cheng-Cheng;A. Bunger
一种新的降阶模型（ROM）提供了快速和合理准确的预测多个，同时增长的径向水力裂缝的复杂行为。该方法需要通过将裂缝之间的应力相互作用的影响的近似耦合在一起来极大地减少通常与该多移动边界问题的完全耦合模拟相关联的自由度（“应力阴影”）与流体流动和弹性的近似，确保保持整体体积平衡，整体能量平衡，弹性，以及裂缝开口与入口流体流量的相容性。用大规模（“高保真度”）模拟验证显示ROM解决方案不仅捕获由于众所周知的应力阴影现象而在均匀间隔阵列中的内部水力裂缝的基本抑制，而且捕获当水力裂缝之间的间隔不均匀时产生的复杂行为。模拟器的有用性通过概念验证优化来证明，由此选择非均匀间距和阶段长度以最大化裂缝表面积和/或与每个增产处理相关的生长均匀性。
A new reduced order model (ROM) provides rapid and reasonably accurate prediction of the complex behavior of multiple, simultaneously growing radial hydraulic fractures. The method entails vastly reducing the degrees of freedom typically associated with fully-coupled simulations of this multiple moving boundary problem by coupling together an approximation of the influence of the stress interaction among the fractures (“stress shadow”) with an approximation of fluid flow and elasticity, ensuring preservation of global volume balance, global energy balance, elasticity, and compatibility of the crack opening with the inlet fluid flux. Validating with large scale (“high-fidelity”) simulations shows the ROM solution captures not only the basic suppression of interior hydraulic fractures in a uniformly-spaced array due to the well-known stress shadowing phenomenon, but also complex behaviors arising when the spacing among the hydraulic fractures is non-uniform. The simulator's usefulness is demonstrated through a proof-of-concept optimization whereby non-uniform spacing and stage length are chosen to maximize the fracture surface area and/or the uniformity of growth associated with each stimulation treatment.