摘要
为了研究滑脱效应的存在条件,以及对页岩气在页岩储层中的渗流规律,基于页岩气的渗流机理和气体渗流的滑脱机制,通过室内实验测定了不同孔隙压力条件下滑脱因子的大小,研究了孔隙压力对页岩气滑脱效应的影响,以及滑脱效应对气体渗透率的影响情况;对含裂缝和不含裂缝的页岩开展了不同孔隙压力下的渗流特征分析。结果表明:页岩中气体滑脱效应是客观存在的;对于不含裂缝的岩心,气体在页岩渗流过程中滑脱效应的强弱很大程度上取决于储层孔隙压力的大小;当储层孔隙压力<1 MPa的时候,滑脱效应明显;当储层孔隙压力大于1 MPa的时候,滑脱效应不明显,整个流动过程为先滑脱流后达西流。对于含明显裂缝的岩心,渗透率随着平均孔隙压力的增大而呈现出三段不同的关系,随着孔隙压力越来越大,渗透率越来越低,且下降趋势越来越大,滑脱效应愈发明显。
To study the existence conditions of slippage effect, and the seepage law of shale gas in shale reservoirs,based on the percolation mechanism and slippage mechanism in shale gas reservoir, experimental tests were conducted to measure the slippage coefficient of differ ent pore pressure,the effect of pore pressure on slippage and slippage on permeability were studied.The effect of slippage on gas permeability was also analyzed.We also analyzed the percolation characteristics under different pore pressures in shale with fractures,as well as in shale without fractures.The results show that slippage exists in shale.For the cores without fractures,the strength of slippage effect largely depends on pore pressure.When pore pressure is less than 1 MPa,slippage effect is obvious with a significant effect on permeability. When pore pressure is larger than 1 MPa,slippage effect is not obvious and the entire flow regime is slippage flow followed by Darcy flow.For cores with fractures,flow regime changes as porepressure increases.With the pore pressure increase gradually,the permeability is more and more low,and the downward trend is more and more big,the slippage effect is more obvious.
出处
《石油化工应用》
CAS
2015年第5期19-23,35,共6页
Petrochemical Industry Application
基金
国家重大科技专项"页岩气开发机理及技术政策研究"
项目编号:2011ZX05018-005
中国南方海相页岩气高效开发的基础研究
项目编号:2013CB228000
关键词
海相页岩
滑脱效应
室内实验
孔隙压力
marine shale
slippage effect
laboratory experiment
pore pressure
