摘要
国内外大量实验研究表明,煤储层应力敏感性是存在的,而且对煤层气井生产有重大影响。在前人实验研究的基础上,建立了煤层渗透率与有效压力或地层压力之间的数学关系式,二者之间满足相关性非常高的指数变化关系;建立了考虑煤储层应力敏感性的达西流动和非达西流动气井产能方程。研究表明,煤储层的应力敏感性对煤层气井的产能有很大影响,随着生产压差的增加,气井的产量增加幅度较小,并逐渐趋向稳定,因此需要制定合理的生产压差进行生产。
A large number of experiments show that stress sensitivity exists in the coal reservoirs and has a significant effect on the gas production of coal-bed methane wells.Based on former experimental results,we set up the mathematical relationship between coal-bed permeability and effective pressure or formation pressure,both of them well fit the exponential correlation.We also build the gas well productivity equation for coal reservoir stress sensitivity under Darcy and non-Darcy steady flow conditions.The result shows that the productivity of coal-bed methane wells are greatly affected by the stress sensitivity.With drawdown pressure increases,gas production increases little,and gradually goes towards stability.So a reasonable drawdown pressure for gas production will be required.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2011年第2期347-351,共5页
Natural Gas Geoscience
基金
国家重点基础研究发展规划("973")项目"高丰度煤层气富集机制及提高开采效率基础研究"(编号:2009CB219604)资助
关键词
煤层气
应力敏感性
产能
稳定流动
达西流动
非达西流动
Coal-bed methane
Stress sensitivity
Productivity
Steady flow
Darcy flow
Non-Darcy flow.
