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现代地质 ›› 2010, Vol. 24 ›› Issue (6): 1198-1203.

• 煤田地质 • 上一篇    下一篇

华北石炭—二叠系煤的孔渗特征及主控因素

刘大锰,姚艳斌, 蔡益栋,张百忍,张可铭,李俊乾   

  1. 中国地质大学 能源学院,北京100083
  • 出版日期:2010-11-19 发布日期:2010-12-30
  • 作者简介:刘大锰,男,教授,博士生导师,1965年出生,矿产普查与勘探专业,主要从事煤层气地质及大气环境有机污染研究。Email: dmliu@cugb.edu.cn。
  • 基金资助:

    国家自然科学基金项目(40972107);国家重点基础研究发展计划项目(2009CB219604);国家科技重大专项项目(2008ZX05034-001);教育部长江学者与创新团队发展计划项目(IRT0864);中国石油天然气股份有限公司创新基金项目(2010D-5006-0101)。

Characteristics of Porosity and Permeability and Their Geological Control of Permo-Carboniferous Coals in North China

LIU Da-meng, YAO Yan-bin, CAI Yi-dong, ZHANG Bai-ren, ZHANG Ke-ming, LI Jun-qian   

  1. School of Energy Resources, China University of Geosciences, Beijing100083,China
  • Online:2010-11-19 Published:2010-12-30

摘要:

煤的低孔、低渗问题已经成为制约我国煤层气勘探和开发的关键问题之一。选取华北河东、渭北、阳泉、晋城、大同和两淮等6个煤田,通过煤岩学特征测试、微裂隙分析和低温氮孔隙结构分析,对该区煤的孔渗发育特征及其控制机理进行了系统研究。华北地区煤的孔隙度在2%~10%之间,孔隙度的大小主要受3次煤化作用跃变所控制,在Ro,r约为12%附近达到最小值。矿物充填作用在一定程度上降低了煤的孔隙度。华北地区煤的渗透率一般都在5×10-3 μm2以下,渗透率与孔隙度呈显著的幂指数关系。无烟煤以微孔为主,孔隙度都在6%以下,渗透率的大小主要取决于裂隙的发育程度;而中低煤级煤的渗透率不仅受裂隙影响,也受煤中各级孔隙发育的影响较大。

关键词: 煤, 孔隙度, 渗透率, 煤层气, 地质控制, 华北

Abstract:

The low porosity and low permeability of coal reservoirs have brought about a big problem for the exploration and exploitation of coalbed methane in China. Based on the coal proximate, coal maceral composition and low-temperature N2 adsorption analyses, microfracture analysis by fluorescence microscope, helium porosity and air permeability analyses, this study investigated the geological control of porosity and permeability of coals in Hedong, Weibei, Yangquan, Jincheng, Datong and Huainan.Huaibei coalfields. The results showed that coal porosity ranged from 2% to 10%, and strongly related to the coalification degree. The porosity reached a minimum value when Ro,r  was about 1.2%. The filling and mineralization of pores by minerals were proven to decrease the coal porosity. Coal permeability is commonly less than 5×10-3μm2, and shows an exponential increment relationship with porosity. The anthracite porosity is commonly less than 6%, which dominated by the micro and meso-pores porosity. The anthracite permeability mainly related to the development of micro and macro-fractures, while the permeability of bituminous and sub-bituminous coals related not only to the fractures but also to the pores.

Key words: coal, porosity, permeability, coalbed methane, geological control, North China

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