华北石炭-二叠系煤的孔渗特征及主控因素.pdf

第24卷第6期
现代地质
Vol 24 No 6
2010年12月
GEOSCIENCE
e.2010
华北石炭一二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
(中国地质大学能源学院,北京100083)
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
大同和两准等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
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5x10-3
um2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;而中低煤级煤的滲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
中图分类号:P6l8
文献标志码:A
文章编号:1000-8527(2010)06-1198-06
Characteristics of Porosity and Permeability and Their Geological Control of
Permo-carboniferous Coals in North China
LIU Da-meng, YAO Yan-bin, CAL Yi-dong, ZHANG Bai-ren, ZHANG Ke-ming, L Jun-qian
(School of Energy Resources, China Unuiersy of Sciences, Beijing 100083, Chi)
Abstract The low porosity and low permeability of coal reservoirs have brought about a big problem for the ex
ploration and exploitation of coalbed methane in China. Based on the coal proximate, coal maceral composition
and lowtemperature N adsorption analyses, microfracture analysis by fluorescence microscope, helium porosity
and air permeability anal es is study inestigated the eol call 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
mnmum vaue when
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 x 10"wm, and shows an exponential in
crement 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
e pores.
Key words; coal; porosity; permeability; coalbed methane; geological control; North China
0引言
果,是煤层气勘探和开发评价的重要参数。我国
二十多年的煤层气勘探开发证明,煤储层的低孔、
煤储层孔渗发育好坏直接影响煤层气开采效低滲问题是制约煤层气商业化进程的关键问题之
收稿日期:2010-07-01;政回日期:2010-09-25;贵任编辑:潘令枝。
基金项目:家自然科学基金项目(40972107);国家重点基础研究发展计划项目(200CB219604);国家科技重大专项项目
(20082X05034-001);教育部长江学者与创新团队发展计划项目(R10864);中国石油天然气股份有限公司创新基
金项日(2010D-5006-0101)。
作者简介:刘大锰,男,教授,博土生导师,19%65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(@cugh.edi.cn。
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