摘要
通过建模分析和实际模拟,研究了多煤层条件下煤层气在成藏史中扩散逸失的地质历史。提出了将煤系中多煤层按照上下边界煤层、主煤层和中间煤层进行合并的煤层气扩散逸失体系简化原则。给出了煤层合并后根据岩性变化和组合特征对扩散系数的校正公式。讨论了将相邻煤层作为内部煤层边界的边界条件设置方法。探讨了模拟煤系上、下部存在烃源岩或其他煤系时顶底边界条件的设置方法。在此基础上,建立了多煤层煤层气扩散逸失的地质模型和数学模型,进而就沁水盆地进行了实例研究。
The geological history of coalbed methane (CBM) emission during the formation of CBM reservoir formation was studied through the design and simulation of the numerical model under the condition of multi-coal seams. Some principles for simplifying multi-coal seams into the upside, bottom, major and middle seams were suggested. A formula for adjusting the CBM emission coefficient in the simplified seams was established according to the lithological composition and variety of the wall rocks. The method for setting the boundary condition, in which the neighbor coal seams could be taken as the boundary of the inner seams, was discussed. The boundary condition was studied in the case that the source rock or coal seams occur above or under the simulated coal series. The geological and mathematical models of the CBM emission in multi-coal-seams then were set up and used in a case study in the Qinshui Basin.
出处
《高校地质学报》
CAS
CSCD
2003年第3期390-395,共6页
Geological Journal of China Universities
基金
国家973计划项目(编号2002CB211704)
国家自然科学基金(编号50134040)
关键词
煤层气
扩散
多煤层
数学模型
边界条件
coalbed methane
multi-coal seam
emission
mathematical model
boundary condition
