鄂尔多斯盆地南部直罗组砂岩的孔渗性特征及其控制因素

Permeability and its controlling factors of sandstone in Zhiluo Formation in the southern part of Ordos Basin

鄂尔多斯盆地南部中侏罗统直罗组的铀成矿条件与盆地北部相似,有形成富大砂岩铀矿的可能性,但较低的渗透性却成为制约盆地南部某些地区成矿的不利因素。分析了研究区内直罗组砂体的物性变化规律,深入讨论了成岩作用对该区直罗组砂岩物性起控制作用,为下一步铀成矿预测提供依据。

The metallogenic conditions for sandstone-type uranium deposits in Zhiluo Formation, Middle Jurassic in the southern part of Ordos Basin are similar to those in the northern part of the basin and consequently it is possible to form large and high-grade uranium deposits. But the permeability of main sand bodies is relatively low which restrains the uranium mineralization in the south area. Based on analyzing the spatial change of physical properties of sand bodies in Zhiluo Formation, the control of diagnesis on physical properties of sandstone has been discussed in the paper, providing a foundation for further prognosis of uranium mineralization in this area.