Flow in multi-scale discrete fracture networks with stress sensitivity
Flow in multi-scale discrete fracture networks with stress sensitivity
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具有应力敏感性的多尺度离散裂缝网络中的流动
DOI：
10.1016/j.jngse.2016.09.025
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发表时间：
2016-09
影响因子：
--
通讯作者：
Wei Shiming
中科院分区：
文献类型：
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作者：
Liang Bin;Jiang Hanqiao;Li Junjian;Gong Changcheng;Jiang Ruyi;Pei Yanli;Wei Shiming
对于页岩储层的水力压裂，天然裂缝的存在对水力裂缝的扩展和多孔介质的流动能力有很大的影响。我们之前的研究主要是基于离散裂缝模型和有限元分析，探讨不同裂缝参数（即方位、孔径）对裂缝网络渗透率的影响（Liang et al., 2016）。为了进一步解释原位条件，我们现在研究应力敏感性（即水力裂缝与天然裂缝之间的应力差）对多尺度离散裂缝网络中流动行为的影响。对存在支撑剂的自然压裂岩心和人工压裂岩心进行了一系列敏感性实验。基于相应的数学拟合模型，建立不同尺度下的裂缝模型，研究应力敏感性对渗流过程的影响。结果表明：随着围压的增加，天然裂缝的渗透率呈指数级下降，而水力裂缝的渗透率下降速度较慢，且服从三次多项式规律；天然裂缝的应力敏感性对渗流动力学的影响大于水力裂缝，这种差异与裂缝的朝向、裂缝长度和相交关系有关。当裂缝方向与压力梯度平行或裂缝可作为主通道的一部分时，应力敏感性对裂缝网络的产能影响较大。在不考虑应力的情况下，水力裂缝周围的排水面积基本相同，但考虑应力敏感性时，天然裂缝的排水面积变化较大。因此，在模拟复杂裂缝性储层时，有必要考虑应力对水力裂缝和天然裂缝导流能力的影响。
For hydraulic fracturing in the shale reservoir, the existence of natural fractures has a great impact on the propagation of hydraulic fractures and the flow capacity of porous media. Our previous study mainly discussed the effect of different fracture parameters (i.e., orientation, aperture) on the fracture network permeability based on discrete fracture model and finite elements analyses (Liang et al., 2016). To further account for the in-situ condition, we now investigate the effect of stress sensitivity, i.e. the stress difference between hydraulic fractures and natural fractures, on flow behavior in multi-scale discrete fracture networks. A series of sensitivity experiments on both naturally and artificially fractured cores with the existence of proppants were carried out. Fracture models at different scale were established based on the corresponding mathematical fitting models, to study the effect of stress sensitivity on the seepage process. Results show that with the increase of confining pressure, the permeability of natural fractures decreases exponentially while the permeability of hydraulic fractures decreases more slowly following the cubic polynomial law. The stress sensitivity of natural fractures has more influence on the flow dynamics than that of hydraulic fractures, and this difference is subject to the fracture orientation, fracture length, and intersection relationship. When the fracture orientation is parallel to pressure gradient or the fracture can serve as part of the main channel, the stress sensitivity has great impact on the productivity of the fracture network. The drainage area around the hydraulic fractures are almost the same irrespective of the stress, but the drainage area of natural fractures changes significantly when considering stress sensitivity. Therefore, it is necessary to incorporate the stress effect on the flow conductivity of hydraulic and natural fractures while modeling complex fractured reservoirs.
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影响因子：
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作者：
Lidong Mi;Hanqiao Jiang;Junjian Li;Tao Li;Yeh Tian
通讯作者：
Lidong Mi;Hanqiao Jiang;Junjian Li;Tao Li;Yeh Tian
DOI：
10.1016/j.jngse.2015.11.005
发表时间：
2015-11-01
影响因子：
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作者：
Ren, Bo;Zhang, Liang;Zhang, Hua
通讯作者：
Zhang, Hua
DOI：
10.1007/3-540-45467-5_4
发表时间：
2000
期刊：
--
影响因子：
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作者：
Peter Bastian;Zhangxin Chen;R. Ewing;R. Helmig;H. Jakobs;Volker Reichenberger
通讯作者：
Peter Bastian;Zhangxin Chen;R. Ewing;R. Helmig;H. Jakobs;Volker Reichenberger
基于离散裂缝模型的有限元分析裂缝参数对裂缝网络渗透率影响的系统研究
影响因子：
--
作者：
Liang Bin;Jiang Hanqiao;Li Junjian;Gong Changcheng
通讯作者：
Gong Changcheng
DOI：
10.2118/167514-ms
发表时间：
2013-08
期刊：
--
影响因子：
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作者：
K. Farayola;A. Olaoye;A. Adewuyi
通讯作者：
K. Farayola;A. Olaoye;A. Adewuyi