摘要
理论分析及矿场实践表明,页岩气藏采用传统渗流模型预测的产量总是比实际产量低,经典的达西渗流定律不再具有适应性,需要建立能准确描述页岩介质气体流动行为的数学模型。目前针对页岩气藏的渗流模型基本都是对传统黏性流动的校正或者在黏性流动模型上简单的附加分子流动项,忽略了黏性流与分子流中间流态的问题。考虑页岩介质中可能存在不同流态,建立了描述页岩气藏的流动分析模型。计算结果表明:页岩储层的孔隙越小、气体分子摩尔质量越小、地层压力越低,气体流动越倾向表现为微观流态,表观渗透率与达西渗透率的比值越大。模型可解释页岩气藏生产时实际产量高于达西模型预测产量,该研究对于指导页岩气藏生产具有重要的指导意义。
Shale gas reservoir theory and field practices showed that the actual yield is higher than the predicted production of traditional seepage flow model,and that classic Darcy percolation law cannot fully describe the shale gas flow behavior of the shale media. Thus a calculation model for accurate description and calculation of gas flow of shale media needs to be established. Existing shale gas reservoir seepage flow models are the correction to traditional viscous flow by simply attached molecular flow,which ignored the middle flow state of the molecular flow and viscous flow,especially for characterization of transition flow. This paper considers different complex flow pattern in shale media to established gas flow analysis model of describing the shale reservoir. The calculation results show that the smaller the porosity of shale reservoir is,the smaller the gas molecular molar mass is and the lower formation pressure could be,the easier gas flow shows the micro flow regime,and the greater the ratio of the apparent permeability to Darcy permeability is. The model reveals the essential reason why the shale reservoir actual yield is higher than predicted yield of Darcy model,and the research has significant guiding importance to direct shale gas reservoir production.
出处
《西南石油大学学报（自然科学版）》
CAS
CSCD
北大核心
2014年第5期111-116,共6页
Journal of Southwest Petroleum University(Science & Technology Edition)
关键词
纳米
表观渗透率
纳米孔隙
水力压裂
黏性流
分子流
过渡流
nanometer
apparent permeability
nanopores
hydraulic fracturing
viscous flow
molecular flow
transition flow
