六盘水地区煤层含气性地质特征及差异成因  

Difference characteristics and main controlling factors in gas-bearing of coal seams in Liupanshui Area

作　　者：高为 韩忠勤[3] 吕放 白利娜 金军 GAO Wei;HAN Zhongqin;LYU Fang;BAI Lina;JIN Jun(Guizhou Provincial Engineering and Technology Research Center of Coalbed Methane and Shale Gas,Guiyang 550008,China;NO.159 Team of Guizhou Coal Geological Bureau,Panzhou 561600,China;Guizhou Research Institute of Petroleum Exploration&Development,Guiyang 550004,China;Guizhou Provincial Coalfield Geology Bureau,Guiyang 550008,China)

机构地区：[1]贵州省煤层气页岩气工程技术研究中心,贵州贵阳550008 [2]贵州省煤田地质局159队,贵州盘州561600 [3]贵州省油气勘查开发工程研究院,贵州贵阳550004 [4]贵州省煤田地质局,贵州贵阳550008

出　　处：《煤炭科学技术》2022年第11期122-130,共9页Coal Science and Technology

基　　金：贵州省科技计划资助项目(黔科合战略找矿[2022]ZD001-01;黔科合支撑[2020]2Y028号);国家科技重大专项资助项目(2016ZX05044001-005)。

摘　　要：六盘水地区是中国南方多煤层特别发育且地质条件较为复杂的地区,近年来煤层气试采效果较好,勘探进展明显,查明该区煤层含气性特征有助于深化对该区煤层气成藏规律的认识,提高勘探成功率。基于研究区多口煤层气参数井实钻资料及煤岩样品测试获取的大量气体组分、含气量、等温吸附及煤岩基础分析数据,分析了六盘水地区煤层含气性的空间差异特征,探讨了煤层含气性差异的关键地质控制因素。结果显示:区内煤层气组分以甲烷为主,中煤阶阶段容易出现重烃异常,重烃组分主要为乙烷,烃类气体与氮气呈高度线性负相关,局部高异常氮气主要来自大气混入,煤层气成因类型多样,且成因类型发生转换的镜质组反射率临界值在1.70%左右。煤层含气量和朗格缪尔体积普遍较高,低煤阶和高煤阶阶段一般为吸附气,中煤阶焦煤部分煤层表现为游离气特征。煤层吸附能力和含气量同时受聚集地质因素和保存地质因素影响,平面上具有一定差异性,影响吸附能力差异的主要因素为煤变质程度和温压环境,影响含气量差异的主要因素为煤变质程度、埋深和构造,一般同一勘探区内朗格缪尔体积的变化相对含气量的变化较小;受聚集地质因素控制,吸附能力和含气量在垂向上不同煤层之间也有一定差异,主要影响因素为煤岩有机显微组分和煤质。The Liupanshui Area is an area with particularly developed coal seams and complex geological conditions in southern China.In recent years, the results of coalbed methane test production in this area is good, and the exploration progress is obvious. Finding out the gas-bearing characteristics of coal seam in this area is helpful to deepen the understanding of the formation and storage rules of coalbed methane, and improve the success rate of exploration. Based on the actual drilling data of several CBM parameter Wells in the study area and a large number of gas components, gas content, isothermal adsorption and basic analysis data of coal and rock obtained from the test of coal and rock samples, the spatial difference characteristics of coal bed gas content in Liupanshui area are analyzed, and the key geological controlling factors of coal seam gas content difference are discussed. The analysis results show that the coalbed methane component in the area is dominated by methane, and heavy hydrocarbons are prone to abnormalities in the middle coal rank stage. The heavy hydrocarbon components are mainly ethane. Hydrocarbon gas and nitrogen are highly linearly negatively correlated, and locally high abnormal nitrogen mainly comes from the atmosphere. There are various types of coal-bed methane genesis, and the critical value of vitrinite reflectance at which the genetic type changes is about 1.70%. The gas content and Langmuir volume of coal seams are generally high. The stage of low and high coal rank is generally adsorbed gas, while the part of coking coal seams of medium coal rank is characterized by free gas. The adsorption capacity and gas content of coal seam are affected by both accumulation geological factors and preservation geological factors, and there are certain differences on the plane. The main factors that affect the difference in adsorption capacity are the degree of coal metamorphism and the temperature and pressure environment, and the main factors that affect the difference in gas content are the d

关 键 词：多煤层 煤层气 含气性 吸附特征 六盘水地区 

分 类 号：TE37[石油与天然气工程—油气田开发工程]