复杂条件下页岩气藏生产特征及规律

Production characteristics and law of shale gas reservoir under complex conditions

王南 2 钟太贤³ 刘兴元⁴ 雷丹凤 2

中国石油勘探开发研究院廊坊分院，河北 廊坊 065007 国家能源页岩气研发（实验）中心，河北 廊坊 065007 中国石油天然气股份公司，北京 100007 中国石油物资公司，北京 100029

从页岩气藏的储层特征、生产机理及压裂施工后气井的产能特征着手，首先分析了页岩储层多孔介质的4个组成部分，确定了有机质孔隙是页岩气主要的储集体，有机质含量及孔隙发育特征直接影响页岩气藏的储量和产量；对页岩气藏的吸附、解析、扩散等渗流机理进行了细致分析，推算游离气与吸附气量，并用压力变化关系曲线解释含气量关系；在产能特征方面运用实例分析了页岩气井产能，确定了单井初期产量高、后期递减迅速和生产周期长等特征，证实了水力裂缝是页岩气藏最主要的气体渗流通道，水力裂缝的形态最终决定气井的产能。研究结果从多方面总结了页岩气藏复杂的生产机理及特征规律，为提高页岩气井产能、规模化开发页岩气藏提供了理论支撑。

This paper focuses on analysis of shale gas reservoir characteristics, production mechanism and productivity characteristics after fracturing. In the study of shale gas reservoir, four components of porous medium for shale reservoir have been analyzed. It is proved that the organic matter is the main reservoir body and seepage channel for free gas. The content of organic matter and the characteristics of pore development directly influence the reserves and production of shale gas reservoir. This paper also analyzes the flow mechanism such as shale gas adsorption, desorption and diffusion, calculates the volumes of free gas and adsorbed gas based on those mechanism and explain the correlation between gas content and pressure history curve. In the analysis of shale gas productivity, the case is used to determine the characteristics of initial high production of single well, fast production decline at late stage and long production cycle. It is confirmed that the hydraulic fracture is the most important flow channel for shale gas. The pattern of hydraulic fracture is key factor to determine the productivity of shale gas. In this study, the production mechanism, characteristics and law of complex shale gas reservoir are summarized, which can provide theory support for improving the productivity of shale gas well and developing the shale gas reservoir on a large scale.

10.6056/dkyqt201206022