鄂尔多斯盆地北部EY-1井太原组黑色泥页岩孔隙特征

Micro pore characteristics of Taiyuan black shale in EY-1 well in northern Ordos Basin

陈崇域 2 刘宇 2 刘刚 2

中国矿业大学煤层气资源与成藏过程教育部重点实验室，江苏 徐州 221116 中国矿业大学资源与地球科学学院，江苏 徐州 221116

MOE Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process, China University of Mining and Technology, Xuzhou 221116, China School of Resources and Geosciences, China University of Mining and Technology, Xuzhou 221116, China

为了研究鄂尔多斯盆地北部页岩气赋存条件，应用氩离子剖光扫描电子显微镜、压汞、低温N2吸附解吸等方法，对鄂尔多斯北部EY￣1井太原组黑色泥页岩微观孔隙类型及特征进行研究。结果表明：泥页岩样品中主要发育有机质孔、粒内孔、黄铁矿晶间孔、粒间孔、溶蚀孔和微裂隙等孔隙类型。其中，微裂隙长度为0.5~3.0 mm，缝宽1~10 μm，连通性较好。高压压汞测得孔隙度平均为0.916 04%，孔径主要集中于微孔和过渡孔，上部的页岩孔隙连通性明显好于下部；用DFT法测得的样品内部孔径小于100 nm，分布呈现双峰，过渡孔较为发育。研究获得的页岩孔隙特征，为鄂尔多斯北部太原组页岩气赋存和储集规律研究提供了重要的参考依据。

In order to study the northern Ordos shale gas occurrence conditions, argon ion polishing/scanning electron microscope, mercury intrusion porosimetry, and low-temperature N2 adsorption/desorption are used to investigate the types and characteristics of micro pores of the black shale(Taiyuan Formation) in the EY-1 well located in northern Ordos, North China. The results show that the pores in the shale samples can be divided into the following types: organic pore, intragranular pore, pore between pyrite crystals, intergranular pore, corrosion hole, and micro crack. These micro cracks with 0.5-3.0 mm in length and 1-10 μm in width exhibit relatively high connectivity. According to the results of the mercury intrusion porosimetry, the average porosity of the shale formation is 0.916 04%; micro and intermediate pores are the main types in terms of pore diameter; and pore connectivity is significantly higher in the upper part of this shale formation than in the lower part. DFT experiment suggests that pores with a diameter smaller than 100 nm distributes in a pattern with two peaks and intermediate pores occur in large quantities in this formation. Characteristics of pores in the shale formation presented in this paper can provide an important reference for research into occurrence and distribution of shale gas in Taiyuan Formation shale (Upper Paleozoic) in Ordos.

10.6056/dkyqt201605005