• 地质勘探 •

### 巨厚煤储层孔隙结构的垂向非均质性特征——以青海聚乎更矿区为例

1. 1. 中国矿业大学(北京)地球科学与测绘工程学院 北京 100083;
2. 山东省菏泽第一中学 山东菏泽 274000
• 收稿日期:2019-05-28 修回日期:2020-04-02 出版日期:2020-06-25 发布日期:2020-07-11
• 通讯作者: 曹代勇,男,1955年8月生,1982年获中国矿业学院学士学位,1991年获中国矿业大学(北京)博士学位,现为中国矿业大学(北京)教授、博士生导师,主要从事煤田构造、盆地构造分析、非常规天然气地质、矿产资源评价与勘查等研究工作。Email:cdycumtb@163.com
• 作者简介:王安民,男,1990年2月生,2013年获中国矿业大学(北京)学士学位,2018年获中国矿业大学(北京)博士学位,现为中国矿业大学(北京)博士后,主要从事煤田构造与煤系非常规天然气研究。Email:wamcumtb@163.com
• 基金资助:

国家自然科学基金项目（No.41902170，No.41572141）资助。

### Vertical heterogeneity characteristics of pore structure for huge thick coal reservoirs: a case study of Juhugeng mining area in Q inghai province

Wang Anmin1, Cao Daiyong1, Nie Jing1,2, Qin Rongfang1

1. 1. College of Geosciences & Surveying Engineering, China University of Minging and Technology, Beijing 100083, China;
2. No.1 Middle School of Heze Shandong, Shandong Heze 274000, China
• Received:2019-05-28 Revised:2020-04-02 Online:2020-06-25 Published:2020-07-11

Abstract:

The Jurassic huge thick coal reservoirs are widely developed in coal-bearing basins in northern China. Taking the Juhugeng mining area in Qinghai as the study area, using SEM, mercury injection, low-temperature liquid nitrogen and other experimental methods, this paper explores the vertical heterogeneity characteristics of pore structure of the Middle Jurassic huge thick coal reservoirs. The results show that there are more pores with good structure developed in fusinite and semifusinite. The higher the content of fusinite and semifusinite, the less complex the pore structure of the sample. Pores are less developed in heterocollinite and homocollinite. The higher the content of heterocollinite and homocollinite, the stronger the heterogeneity of pore structure of the sample. Based on the vitrinite/intertinite ratio and gelation index, the huge thick coal reservoirs in the study area are classified into three regression cycles, i.e., Cycle Ⅰ, Cycle Ⅱ and Cycle Ⅲ. The fractal dimension of the macro and small pores shows a decrease with regression, and the pore volume of macropores and mesopores and the porosity of mesopores increase with regression. The fact is that the regression leads to an increase in the content of fusinite and semifusinite, so that the pore volume increases and pore structure is less complex. The comparison of pore structures of the three cycles indicates that Cycle Ⅰ has poorer pore connectivity than Cycle Ⅱ and Cycle Ⅲ. Overall, the porosity distribution is shown as Cycle Ⅰ > Cycle Ⅱ > Cycle Ⅲ; the complexity of the macropore structure is shown as Cycle Ⅲ > Cycle Ⅰ > Cycle Ⅱ, the complexity of the mesopore pore structure is shown as Cycle Ⅰ > Cycle Ⅱ > Cycle Ⅲ, and there is no much difference in the pore structure of small pores in each cycle. It is an effective method to study the physical properties of huge thick coal reservoirs by dividing the cyclicity and comparing the differences in pore structure of each cycle, which can provide certain theoretical support for the reservoir evaluation and exploration and development of huge thick coal reservoirs.