页岩气扩散渗流机理及产气规律研究

项目名称： 页岩气扩散渗流机理及产气规律研究

项目编号： No.51504269

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 矿业工程

项目作者： 石军太

作者单位： 中国石油大学（北京）

项目金额： 21万元

中文摘要： 页岩气的成功开发须建立在认清产气规律的基础上，而页岩气在基质孔隙中的传递机理是攻克产气规律的瓶颈。页岩气传递机理及产气规律这一科学问题可分解为：（1）页岩基质块的润湿性如何？（2）页岩有机质-无机质孔隙中气水分布及差异性？（3）页岩有机质-无机质孔隙中甲烷的赋存机理及赋存状态？（4）页岩气在基质纳米孔隙中的传递方式是扩散、渗流还是其他运动方式？（5）页岩气井产气规律如何预测？目前页岩气在基质孔隙中的传递模型没有考虑有机质与无机质含量对传递的影响，造成气井产气变化规律认识不清，现有模型预测结果与实际生产动态偏差较大。因此，本课题拟从页岩基质孔隙分布和气水分布入手，研究页岩气在基质孔隙中扩散、渗流多机理耦合的传递机理，建立考虑有机质含量和努森数范围的传递模型，进而建立相应的产气模型，揭示页岩气井的产气规律。本研究将为页岩气界提供一套更准确的生产动态预测方法，为页岩气的合理开发提供科学依据。

中文关键词： 页岩气；纳米孔隙；扩散；渗流；产气规律

英文摘要： The successful development of the shale gas must be based on deep understanding of the discipline of gas production, but the transport mechanism of shale gas through matrix pores is the bottleneck of conquering the difficulties in shale gas development. The scientific problem, transport mechanism of shale gas through matrix pores and gas production discipline, can be divided into: (1) What’s the wettability of shale matrix? (2) What’s the distribution of the water in nanoscale shale matrix pores? (3) What’s gas occurrence mechanism and state in organic and inorganic matrix pores? (4) Is the transport mechanism of shale gas through matrix pores diffusion, seepage, or other mode of motion? (5) How to forecast the shale gas production? The influence of organic and inorganic mass ratio was not considered in the present transport models of shale gas through matrix pores, which results in an unclear recognizing of the shale gas production discipline and the large derivation between prediction results by the present models and actual performance of shale gas wells. Therefore, in this work, the size distribution of shale matrix pores and the water distribution in shale matrix pores are investigated first, then diffusion-slippage-flow coupled transport mechanism of shale gas through matrix pores is proposed, and the transport model considering the organic content and the range of Knudsen number is established. Finally, the relevant gas production model is established and the shale gas production discipline is revealed. Our study will provide a more accurate technique for forecasting shale gas production, and moreover, it will provide scientific evidence to the rational development of shale gas reservoirs.

英文关键词： Shale gas;nano pores;diffusion;flow;gas production discipline