• 非常规油气 •

### 基于反常扩散模型的页岩气藏压裂水平井产能研究

1. 西南石油大学油气藏地质及开发工程国家重点实验室,四川 成都 610500
• 收稿日期:2018-04-11 出版日期:2019-02-26 发布日期:2019-02-15
• 作者简介:李勇明（1974—），男，博士生导师，油气藏压裂酸化理论与应用研究。
• 基金资助:
四川省青年科技创新研究团队专项计划项目“页岩气体积压裂排液控制技术研究”(2017TD0013);国家自然科学基金重大项目“页岩地层动态随机裂缝控制机理与无水压裂理论”(51490653)

### Research on productivity of fractured horizontal wells in shale gas reservoirs based on anomalous diffusion model

Li Yongming,Wu Lei,Chen Xi

1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China
• Received:2018-04-11 Online:2019-02-26 Published:2019-02-15

Abstract:

After the volume fracturing of shale gas reservoirs, due to the abrupt variations in the pore scale of the gas seepage and the severe difference between the characteristics of shale matrix and fractures, the seepage velocity field showed a sharp discontinuity, resulting in the failure of continuum assumption. In order to accurately understand the flow pattern of shale gas reservoirs and analyze the productivity, based on the trilinear flow model of fractured horizontal wells in shale gas reservoirs and coupled with the anomalous diffusion equation of fractal porous media, we established a fractured horizontal well productivity model of shale gas reservoirs. The dimensionless production was obtained by Laplace transform and Stehfest numerical inversion. Finally, we analyzed its result combining specific example and obtained a dimensional production curve. The analysis results showed that five flow regions for shale gas could be identified, including the linear flow stage of hydraulic fractures, the bilinear flow in hydraulic fractures and natural fractures, the linear flow stage of natural fractures, the bilinear flow in natural fractures and matrices, and the phase of matrix linear flow. Based on the production model, we also studied the influence of anomalous diffusion exponent, pseudo-permeability, storability ratio, fracture spacing and the like. on the production of shale gas reservoirs. The results indicated that the smaller abnormal diffusion exponent and the stronger matrix heterogeneity were, the more obvious decrease of productivity would be, and the natural fractures pseudo-permeability had great impact on the length of time in the linear flow of the natural fractures. Furthermore, the hydraulic fracture pseudo-permeability could influence the productivity in the whole middle-late production cycle. The larger the storability ratio was, the more obvious increase amplitude of productivity would be. The research provided a new idea and method for productivity analysis and evaluation of shale gas reservoirs.

• TE312