高级检索

陕北榆神矿区富油煤分布规律及形成控制因素

Distribution and geological controls of tar-rich coals in Yushen mining area of Northern Shaanxi

  • 摘要: 富油煤开发利用对实现我国煤炭清洁低碳利用、缓解油气供应紧张、保障国家能源安全具有重要意义。鉴于此,基于焦油产率分级划分,对榆神矿区延安组主采煤层富油煤时空分布特征进行了研究,对影响焦油产率的地质因素进行了探讨。结果表明,该区总体以富油-高油煤为主。垂向上,3-1号煤层焦油产率最高,富油煤和高油煤分布面积最大,其次为2-2号煤层,5-2号煤层相对最小。平面上,焦油产率呈东南部高,西北部低的变化趋势,除局部分布含油煤外,其他区域均被富油煤和高油煤覆盖。高油煤在矿区东南部连续分布,东北部零星分布,其中3-1号煤层高油煤分布面积最大且连续性最好。富油煤的形成主要受煤化程度、成煤物质、成煤环境等因素影响。较低的煤化程度对富油煤的发育极为有利,富油煤和高油煤发育比例达96%以上。较高的富氢镜质组含量为富油煤的发育提供了良好物质基础,富氢镜质组(基质+均质镜质体)含量为高油煤>富油煤>含油煤,富油煤和高油煤的富氢镜质组分含量占全岩显微组分的比例均在50%以上,氢元素含量均在4%以上。强还原性环境为富油煤的生成和富集提供了良好条件,富油煤主要形成于三角洲平原到滨浅湖沉积环境,覆水深度越大,还原性越强,越有利于形成高焦油产率煤;高油煤主要形成于东南部覆水深度最大、还原性最强的滨浅湖环境。

     

    Abstract: The development and utilization of tar-rich coal is of great significance for achieving clean and low-carbon utilization of coal in our country,alleviate the shortage of oil and gas supply,and ensuring national energy security. In view of this,based on the classification of tar yield,the temporal and spatial distribution characteristics of tar-rich coal in the main coal seam of Yan’an Formation in Yushen Mining Area were studied,and the geological factors affecting tar production rate were discussed. The results show that the area is generally dominated by rich-high tar coal.Vertically,coal seam 3-1 has the highest tar yield and the largest distribution area of tar-rich coal and high-tar coal,followed by coal seam 2-2 and coal seam 5-2.On the plane,the tar yield is high in the southeast and low in the northwest. Except for the local distribution of tar-containing coal,other areas are covered by tar-rich coal and high-tar coal. High-tar coal is continuously distributed in the southeastern of the mining area,and sporadically distributed in the northeast. Among them,the high-tar coal in coal seam No. 3-1 has the largest area and the best continuity. The formation of tar-rich coal is mainly affected by factors such as the degree of coalification,coal-forming materials,and coal-forming environment. A low degree of coalification is extremely beneficial to the development of tar-rich coal,and the development ratio of tar-rich coal and high-tar coal reaching more than 96%. The high content of hydrogen-rich vitrinite provides a good material basis for the development of tar-rich coal. The content of hydrogen-rich vitrinite (matrix+homogeneous vitrinite) is high-tar coal>tar-rich coal>tar-containing coal.The hydrogen-rich vitrinite content of tar-rich coal and high-tar coal accounts for more than 50% of the whole rock macerals,and the hydrogen content is more than 4%.The strong reducing environment provides good conditions for the formation and enrichment of tar-rich coal.Tar-rich coal is mainly formed in the depositional environment of delta plains to shallow lakes.The greater the depth of overlying water,the stronger the reducibility,which is more conducive to the formation of coal with high tar yield. High-tar coal is mainly formed in the coastal shallow lake environment with the largest water covering depth and the strongest reducibility in the southeast.

     

/

返回文章
返回