摘要
煤层群在我国分布广泛,其典型特征是煤层层数多、层间距大。目前煤层群条件下多煤层合采中产气来源不易判识,合采方案难以合理制定,合采难以实现产能叠加,致使煤层气井产气量低、开发效率低。为此,以安徽淮南矿区顾桥井田为例,基于各煤层取心样品解吸气测试结果,提取解吸气中气体成分体积分数特征信息,建立煤层解吸气源判识标准模板,并以5口合采试验井为例进行了初步判识,进而研究多煤层合采中产气源判识方法。研究结果表明:煤层的解吸气中蕴含着丰富的产出气来源信息,基于4层煤层解吸气成分体积分数差异,提取CH_(4)/C_(2+)、N_(2)/C_(2+)、CO_(2)/C_(2+)和N_(2)/CO_(2)四组特征体积分数比值数据,建立了单层煤层数据投点法的交汇图和蛛网图标准模板。应用这一标准模板判识了5口合采试验井的产气来源,发现顾桥井田的产气层主要为13-1煤层和11-2煤层,6-2煤层和1煤层的产气贡献微乎其微,认为煤层间距大是影响顾桥井田多煤层合采产能叠加的主要因素。为此,构建了由提取解吸气特征体积分数、建立单煤层解吸气特征体积分数标准模板、产出气来源判识3个步骤组成的评价流程,可快速、准确地进行多煤层合采产出气源判识。
Coal seam group is widely distributed in China.Its typical characteristics are many layers of coal seam and large interval between layers.At present,multiple coal seams in coal seam group have been difficult to identify the source of coalbed methane and formulate reasonable plan for coalbed methane production in multiple coal seams,resulting in low output and development efficiency of coalbed methane.Therefore,taking the Guqiao well field in Huainan mining area as an example,based on the analysis results of desorption gas test of coal seam samples,the characteristic information of desorption gas component volume fraction is extracted,the standard template of identification of desorption gas source in coal seam is established,and 5 test wells are taken as examples for preliminary identification.Furthermore,the method of identification of gas source in multiple coal seam combination production is studied.The results show that the desorption gas of coal seam contains abundant information about the source of gas.Based on the volume fraction difference of desorption gas components in the four layers coal seam,the characteristic volume fraction ratio data of CH_(4)/C_(2+),N_(2)/C_(2+),CO_(2)/C_(2+)and N_(2)/CO_(2)are extracted,and the standard template of single layer coal seam of intersection diagram method and cobweb method is established.Using this standard template,the gas sources of 5 test wells were identified,and it was concluded that the gas contribution of Guqiao well field was mainly 13-1 coal and 11-2 coal,and 6-2 coal and 1 coal was very little.It is thinking that the large interval is the main factor affecting the superposition of multiple coal seam combination production in Guqiao well field.The evaluation process,which consists of three steps:extracting the characteristic volume fraction of desorption gas,setting up the standard template of the characteristic volume fraction of desorption gas of single coal seam,and identifying the source of coalbed methane,can be quickly and accurately used to identify the source of coalbed methane from multiple coal seam combination production.
作者
许耀波
XU Yaobo(Xi’an Research Institute of China Coal Technology and Engineering Group,Xi’an 710054,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2020年第S01期367-376,共10页
Journal of China Coal Society
基金
国家自然科学基金资助项目(51874349)
中国煤炭科工集团有限公司科技创新创业资金资助项目(2018MS008)
关键词
煤层气
合层开发
解吸气成分
气体体积分数
气源解析
产层判识
coalbed methane
commingling production
desorption gas component
gas component volume fraction
gas origin parsing
production layer identification
作者简介
许耀波(1983-),男,湖南衡阳人,副研究员。E-mail:xuyaobo@cctegxian.com
