摘要: |
为探究考虑应力干扰作用下多簇压裂水平井产能分布规律,有机结合多簇裂缝扩展与产能计算模型开展数值模拟研究。首先基于位移不连续法建立多簇裂缝同步扩展数学模型,采用牛顿迭代法构建求解算法;其次应用位势理论和叠加原理,通过划分裂缝单元的方法,考虑裂缝无限导流和有限导流能力两种情形,构建产能计算方法。结果表明:多簇裂缝同步扩展时,应力干扰作用不仅影响裂缝扩展路径,而且还影响裂缝几何参数,然而此应力干扰作用有利于提高井产量;产量与裂缝间距、半长有关,且裂缝间距对产量的影响程度高于裂缝半长的影响程度;考虑裂缝变导流能力时产量低于考虑裂缝恒定导流能力时产量;提出的计算方法可用于计算任意裂缝形态下产能分布,与实际情况更加相符。 |
关键词: 水平井 多簇压裂 应力干扰 裂缝扩展 产能计算 |
DOI:10.3969/j.issn.1673-5005.2019.01.012 |
分类号::TE 315 |
文献标识码:A |
基金项目:国家自然科学基金项目(51234007,4,51404291) |
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Production distribution in multi-cluster fractured horizontal wells accounting for stress interference |
ZENG Qingdong1, TONG Ying2, YAO Jun1
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(1.School of Petroleum Engineering in China University of Petroleum(East China), Qingdao 266580, China;2.SINOPEC Research Institute of Petroleum Engineering, Beijing 100101, China)
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Abstract: |
In order to investigate the production distribution in multi-cluster fractured horizontal wells in consideration of stress interference, numerical simulation has been conducted in combination of multi-cluster fracture propagation and production calculation models. Firstly, a mathematical model of multi-cluster fracture propagation was established based on a displacement discontinuity method and the algorithm of the model was solved by the Newton iteration method. Secondly, based on the potential theory and superposition principle, the calculation method of productivity was proposed by discretizing the fractures into elements under two scenarios with infinite fracture conductivity and finite conductivity. The results of a case study show that, when multi-cluster fractures propagate simultaneously, the effect of the stress interference not only affect the path of the fracture propagation but also influences the fracture 's geometry. However, the effect of the stress interference is beneficial for improving the well production. The well production is related to the fracture spacing and fracture half length, and the effect of the former is stronger than that of the latter. The predicted production with consideration of a variable conductivity of fractures is lower than that when considering a constant conductivity. The results show that the proposed method can be used to calculate the productivity distribution with any fracture configuration, which is more consistent with the actual situation. |
Key words: horizontal wells multi-cluster fracturing stress interference fracture propagation productivity prediction |