Numerical studies of interactions between hydraulic and natural fractures by Smooth Joint Model
Numerical studies of interactions between hydraulic and natural fractures by Smooth Joint Model
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通过平滑节理模型对水力裂缝和天然裂缝之间相互作用的数值研究
DOI：
10.1016/j.jngse.2017.07.030
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发表时间：
2017-10
影响因子：
--
通讯作者：
Han Zhenhua
中科院分区：
文献类型：
--
作者：
Zhou Jian;Zhang Luqing;Pan Zhejun;Han Zhenhua
水力压裂技术是天然气生产过程中提高储层渗透率的关键技术。水力压裂理论和实践已经取得了重大进展，但天然裂缝储层裂缝模式的精确预测仍需要进一步研究。为了实现水力压裂的更广泛应用，应该充分了解影响水力裂缝（HF）和天然裂缝（NF）之间相互作用的机制。在本文中，首次使用嵌入平滑节理模型（SJM）的二维粒子流代码（PFC2D）来模拟水力裂缝（HF）和天然裂缝（NF）之间相互作用的细节。首先，验证了SJM模拟天然岩石节理的能力，并介绍了流体-机械耦合机制。其次，考虑到井眼中注入压裂液，模拟驱动的 HF 和预先存在的 NF 之间的相互作用。最后，研究了接近角和地应力的影响。结果发现，该模型能够模拟 HF 和 NF 之间的各种相互作用，例如直接交叉、偏移交叉以及 HF 被 NF 捕获。在大接近角和高差应力下，HF 倾向于与预先存在的 NF 交叉；相反，HF更有利于沿着NF传播并在NF的薄弱点或尖端重新引发。此外，我们的数值结果与基于修正的 Renshaw 和 Pollards 准则的分析结果非常吻合。因此，该数值方法可能成为优化天然裂缝性页岩气藏裂缝设计的有用而有力的工具。
The hydraulic fracturing technology is a key for enhancing the permeability of reservoirs during the production of natural gas. Significant progress has been made in hydraulic fracturing theory and practices, however, precise prediction of the fracture patterns in naturally fracture reservoirs still requires further study. The mechanisms influencing the interaction between hydraulic fracture (HF) and natural fracture (NF) should be well understood to achieve a wider application of hydraulic fracturing. In this paper, it is the first time to simulate the details of the interactions between hydraulic fractures (HFs) and natural fractures (NFs) using two-dimensional particle flow code (PFC2D) with embedded Smooth Joint Model (SJM). Firstly, the ability of SJM to emulate the natural rock joint was validated, and the fluid-mechanically coupled mechanism was introduced. Secondly, the interactions between a driven HF and a pre-existing NF were simulated considering fracturing fluid injection in a borehole. Lastly, the influence of approach angles andin-situdifferential stress were studied. It is found that the model is capable of simulating the variety of interactions between HFs and NFs such as direct crossing, crossing with an offset and HFs arrested by NFs. Under high approach angles and high differential stresses, the HF tend to cross pre-existing NFs; on the contrary, a HF is more favorable to propagate along the NF and re-initiate at the weak point or the tip of NF. Moreover, our numerical results agree well with the analytical results based on the modified Renshaw and Pollards' criterion. Therefore, this numerical method may become a useful and powerful tool for optimizing fracture design in naturally fractured shale gas reservoirs.
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影响因子：
6.2
作者：
Liu, Zhiyuan;Chen, Mian;Zhang, Guangqing
通讯作者：
Zhang, Guangqing
影响因子：
--
作者：
A. Al-Busaidi;J. Hazzard;R. P. Young
通讯作者：
A. Al-Busaidi;J. Hazzard;R. P. Young
影响因子：
6.1
作者：
A. A. Daneshy-A.
通讯作者：
A. A. Daneshy-A.
DOI：
10.1016/0148-9062(96)83899-x
发表时间：
--
期刊：
--
影响因子：
--
作者：
E. C.
通讯作者：
E. C.
DOI：
10.2118/419-pa
发表时间：
1963-02
期刊：
Journal of Petroleum Technology
影响因子：
--
作者：
N. Lamont;F. W. Jessen
通讯作者：
N. Lamont;F. W. Jessen