The relationship between the pressure threshold and the permeability-porosity of thesame sample has been studied. The experimental results show that the relationship betweenthe flow rate and pressure drop in the capil...The relationship between the pressure threshold and the permeability-porosity of thesame sample has been studied. The experimental results show that the relationship betweenthe flow rate and pressure drop in the capillary porous media is similar to that of the lam-inar flow in ordinary pipes and channels. However, the conventional hydrodynamics anddimensional analysis are not sufficient to unify the permeability-porosity relationship. Thepermeability of the narrow screened particle packed bed is not linear function of the squareof the particle or channel size. There is a pressure threshold pth occurring in a very thinlayer of wet sand when gas is forced into them, which is a capillary pressure behavior of theporous media. The threshold diameter, defining as dth=4a/pth, can unify all the experi-mental results of the permeability-porosity. The threshold diameter is neither particle sizenor channel size in the porous media. It is a non-geometrical quantity in length unit.展开更多
突破压力是气藏开采和盖层评估中的重要参数。文章选取柴达木盆地东部石炭系低渗砂岩岩心3块,对每块岩心进行6个不同含水率下的突破压力试验。通过XRD、XRF分析方法对砂岩的矿物成分、化学成分进行定量测试;利用氦气双室法与压汞试验对...突破压力是气藏开采和盖层评估中的重要参数。文章选取柴达木盆地东部石炭系低渗砂岩岩心3块,对每块岩心进行6个不同含水率下的突破压力试验。通过XRD、XRF分析方法对砂岩的矿物成分、化学成分进行定量测试;利用氦气双室法与压汞试验对砂岩的孔隙度和孔径分布特征进行分析;用CH4气体模拟渗流试验对砂岩的绝对渗透率进行分析。结果表明:研究区低渗砂岩孔隙度在9.02%~10.96%之间,平均孔隙半径在0.1082~0.3709μm之间,绝对渗透率在0.008~0.012 m D之间,干岩石突破压力值在0.05~0.19 MPa之间,饱和岩石突破压力值在1.51~2.73 MPa之间。黏土矿物遇水膨胀对孔隙结构不会造成显著性改变,因此对突破压力没有明显影响。影响突破压力的主要因素是孔隙结构和含水率。试验结果表明突破压力与岩石孔隙大小之间呈现负相关的关系,随着平均孔径和中值半径的增大,突破压力随之降低。本研究得到了突破压力与含水率之间的定量函数关系:突破压力随含水率增加呈指数函数形式增加。展开更多
文摘The relationship between the pressure threshold and the permeability-porosity of thesame sample has been studied. The experimental results show that the relationship betweenthe flow rate and pressure drop in the capillary porous media is similar to that of the lam-inar flow in ordinary pipes and channels. However, the conventional hydrodynamics anddimensional analysis are not sufficient to unify the permeability-porosity relationship. Thepermeability of the narrow screened particle packed bed is not linear function of the squareof the particle or channel size. There is a pressure threshold pth occurring in a very thinlayer of wet sand when gas is forced into them, which is a capillary pressure behavior of theporous media. The threshold diameter, defining as dth=4a/pth, can unify all the experi-mental results of the permeability-porosity. The threshold diameter is neither particle sizenor channel size in the porous media. It is a non-geometrical quantity in length unit.
文摘突破压力是气藏开采和盖层评估中的重要参数。文章选取柴达木盆地东部石炭系低渗砂岩岩心3块,对每块岩心进行6个不同含水率下的突破压力试验。通过XRD、XRF分析方法对砂岩的矿物成分、化学成分进行定量测试;利用氦气双室法与压汞试验对砂岩的孔隙度和孔径分布特征进行分析;用CH4气体模拟渗流试验对砂岩的绝对渗透率进行分析。结果表明:研究区低渗砂岩孔隙度在9.02%~10.96%之间,平均孔隙半径在0.1082~0.3709μm之间,绝对渗透率在0.008~0.012 m D之间,干岩石突破压力值在0.05~0.19 MPa之间,饱和岩石突破压力值在1.51~2.73 MPa之间。黏土矿物遇水膨胀对孔隙结构不会造成显著性改变,因此对突破压力没有明显影响。影响突破压力的主要因素是孔隙结构和含水率。试验结果表明突破压力与岩石孔隙大小之间呈现负相关的关系,随着平均孔径和中值半径的增大,突破压力随之降低。本研究得到了突破压力与含水率之间的定量函数关系:突破压力随含水率增加呈指数函数形式增加。
