西南石油大学学报(自然科学版) ›› 2021, Vol. 43 ›› Issue (5): 84-96.DOI: 10.11885/j.issn.1674-5086.2021.02.28.04

• 非常规油气开发专刊 • 上一篇    下一篇

页岩气藏压裂缝网扩展流动一体化模拟技术

盛广龙, 黄罗义, 赵辉, 饶翔, 马嘉令   

  1. 长江大学石油工程学院, 湖北 武汉 430100
  • 收稿日期:2021-02-28 发布日期:2021-11-05
  • 通讯作者: 赵辉,E-mail:zhaohui@yangteu.edu.cn
  • 作者简介:盛广龙,1990年生,男,汉族,江苏徐州人,副教授,主要从事非常规油气渗流理论与应用、智能油气田开发生产优化技术等方面的研究工作。E-mail:shenggl2019@yangtzeu.edu.cn
    黄罗义,1996年生,男,汉族,湖北黄冈人,硕士研究生,主要从事非常规储层体积压裂缝网扩展方向的研究。E-mail:202071271@yangteu.edu.cn
    赵辉,1984年生,男,汉族,山东乐陵人,教授,博士生导师,主要从事智能油气开发优化理论、油藏数值模拟、三次采油开发理论等研究。E-mail:zhaohui@yangteu.edu.cn
    饶翔,1994年生,男,汉族,湖北孝感人,讲师,主要从事油气藏智能开发生产优化技术、非常规油气藏数值模拟、数值计算方法等方面的研究工作。E-mail:raoxiang0103@163.com
    马嘉令,1997年生,男,汉族,河北石家庄人,硕士研究生,主要从事非常规油气渗流理论与应用、油藏工程及优化控制工程等方面的研究工作。E-mail:201971195@yangtzeu.edu.cn
  • 基金资助:
    国家自然科学基金(52004033);国家优秀青年基金(51922007)

Integrated Simulation Approach for Fracture Network Propagation and Gas Flow in Shale Gas Reservoirs

SHENG Guanglong, HUANG Luoyi, ZHAO Hui, RAO Xiang, MA Jialing   

  1. College of Petroleum Engineering, Yangtze University, Wuhan, Hubei 430100, China
  • Received:2021-02-28 Published:2021-11-05

摘要: 页岩气藏天然裂缝分布复杂,地层非均质性强,水平井压裂技术是开发的必要手段,建立页岩气藏压裂缝网扩展与流动一体化模拟方法对于制定生产方案及评价压裂措施具有重要的现实意义。采用基于闪电模拟的油藏压裂裂缝网络扩展计算方法来模拟页岩气藏多分支裂缝网络形态,在此基础上进一步运用嵌入式离散裂缝模型(EDFM)来定量表征页岩气藏有机质-无机质-裂缝网络之间的复杂流动机制,从而实现页岩气藏压裂缝网扩展流动一体化模拟。基于该方法建立了200 m×200 m的地质模型进行缝网形态模拟以及流动表征,通过缝网扩展模拟方法得到裂缝网络分布规律,在此基础上基于嵌入式离散裂缝模型进行流动模拟,得到模型生产200 d后的含气饱和度分布以及产气量分布曲线。同时,基于本文模型分析了压裂液注入压力、分形概率指数、压裂液黏度以及裂缝网格精细程度等参数对裂缝网络形态、含气饱和度分布以及页岩气产量的影响。研究表明,压裂液注入压力越高分形概率指数越小、压裂液黏度越小裂缝扩展范围越大、含气饱和度下降范围越大单井产量越高,裂缝模拟精度会显著影响产量误差。基于该页岩气藏压裂缝网扩展流动一体化模型可以大规模模拟页岩气藏缝网形态以及多重介质复杂流动,为评价页岩气藏压裂施工好坏以及产量预测提供了有效的帮助。

关键词: 页岩气藏, 水力压裂, 缝网扩展, 流动表征, 一体化模拟

Abstract: The distribution of natural fractures in shale gas reservoirs is complex, and the reservoir heterogeneity is strong. Hydraulic fracturing of horizontal wells is a necessary way for its development. Establishing an integrated simulation method for fracturing network propagation simulation and flow simulation in shale gas reservoirs has important practical significance for formulating production plans and evaluating the quality of hydraulic fracturing. In this paper, the fracture propagation calculation method based on lightning simulation is used to simulate the multi-branch fracture network pattern of shale gas reservoirs. On this basis, the embedded discrete fracture model (EDFM) is further used to quantitatively characterize the complex flow mechanism between the organic matter-inorganic matter-fracture network of shale gas reservoirs, so as to realize the integrated simulation of fracture network propagation and gas flow in shale gas reservoirs. Based on this method, a 200 m×200 m geological model was established to simulate fracture morphology and flow characterization. The fracture network distribution is obtained by the fracture network propagation simulation method, and the flow simulation is carried out based on the embedded discrete fracture model. The gas saturation distribution and gas production are obtained. At the same time, based on this model, the influence of parameters such as fracturing fluid injection pressure, fractal probability index, fracturing fluid viscosity and fracture simulation accuracy on fracture network, gas saturation distribution and shale gas production is analyzed. Research shows that:the higher the fracturing fluid injection pressure is, the smaller the fractal probability index is, the smaller the fracturing fluid viscosity is, the larger the fracture propagation range will be, the greater the gas saturation reduction range will be, and the higher the single well production will be; the fineness of the fracture grid will significantly affect the production. This model can simulate the shale gas reservoir fracture network pattern, and the complex flow of multiple media on a large scale, which provides effective help for evaluating the hydraulic fracturing of shale gas reservoirs and predicting production.

Key words: shale gas reservoir, hydraulic fracturing, fracture network propagation, flow simulation, integrated simulation

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