首页> 外文期刊>Journal of natural gas science and engineering >Numerical study of a stress dependent triple porosity model for shale gas reservoirs accommodating gas diffusion in kerogen
【24h】

Numerical study of a stress dependent triple porosity model for shale gas reservoirs accommodating gas diffusion in kerogen

机译:页岩气藏适应干酪根中气体扩散的应力相关三重孔隙模型的数值研究

获取原文
获取原文并翻译 | 示例
           

摘要

A model accommodating multi-scale pores containing kerogen within an inorganic matrix is used to explore the complex multi-mechanistic transport mechanisms of shale gas reservoirs. These include the complex evolution of pressure, diffusion and flow within both kerogen and inorganic components and their interaction with effective stresses. A general poromechanical model is proposed considering desorption and molecular diffusion in the kerogen, viscous flow in the inorganic matrix and fracture system, and composite deformation of the triple porosity assemblage. The model is verified by history matching against field data for gas production rate. The simulation results indicate that the pattern of gas flow is sequential during gas depletion pressure first declines in the fracture, followed by the inorganic phase and then in the kerogen. The evolution of permeability is pressure dependent and the evolution of pressure is closely related to the intrinsic gas diffusion coefficient in the kerogen, inorganic matrix intrinsic permeability and fracture intrinsic permeability. A series of sensitivity analyses are completed to define key parameters affecting gas production. The study shows that dominant influence of the fracture network in acting as the main permeable conduit. The intrinsic permeability and porosity of the fracture have a positive correlation with gas production, while fracture spacing has a negative correlation to gas production. Kerogen also plays a critical role in gas production for shale reservoirs with higher total organic carbon. The enhancement of inorganic matrix permeability and gas diffusion coefficient in kerogen could efficiently guarantee a long-term gas production with a higher rate. (C) 2016 Elsevier B.V. All rights reserved.
机译:利用一个在无机基质中容纳干酪根的多尺度孔隙的模型,探讨了页岩气藏复杂的多机理输运机理。这些包括干酪根和无机组分内压力,扩散和流动的复杂演变以及它们与有效应力的相互作用。考虑到干酪根的解吸和分子扩散,无机基质和断裂体系中的粘性流以及三重孔隙组合的复合变形,提出了一种一般的孔隙力学模型。通过历史记录与针对天然气生产率的现场数据进行匹配来验证该模型。模拟结果表明,在瓦斯耗竭压力下降的过程中,气流的顺序是连续的,先是在裂缝中,然后是无机相,然后是干酪根。渗透率的变化与压力有关,压力的变化与干酪根中的固有气体扩散系数,无机基质的固有渗透率和裂缝的固有渗透率密切相关。完成了一系列敏感性分析,以定义影响天然气生产的关键参数。研究表明,裂缝网络在充当主要渗透管道方面具有主导作用。裂缝的固有渗透率和孔隙率与产气量呈正相关,而裂缝间距与产气量呈负相关。干酪根在总有机碳含量较高的页岩储层的天然气生产中也起着关键作用。干酪根中无机基质渗透性和气体扩散系数的增加可以有效地保证长期较高产气率。 (C)2016 Elsevier B.V.保留所有权利。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号