陕北榆神矿区富油煤深成变质的古地质温度计算方法初探  

Study on the calculation methods of paleogeo temperature of oil-rich coal in Yushen Mining Area in Northern Shaanxi

作　　者：张学梅[1] 李东[1] 马青华[1] 郝静远 ZHANG Xue-mei;LI Dong;MA Qing-hua;HAO Jing-yuan(Energy&Chemical Engineering Research Center,Xi’an Siyuan University,Xi’an,Shaanxi 710038,China;College of Chemical Engineering,Xi’an Jiaotong University,Xi’an,Shaanxi 710049,China)

机构地区：[1]西安思源学院能源及化工大数据应用教学研究中心,陕西西安710038 [2]西安交通大学化工学院,陕西西安710049

出　　处：《煤炭加工与综合利用》2023年第6期63-69,共7页Coal Processing & Comprehensive Utilization

摘　　要：根据陕北榆神矿区2-2号、3-1号、5-2号煤层的地质概况(位置、镜质体反射率和平均镜质体反射率),利用吴氏煤变质热动力学方程计算古地质温度为54.2~79.4℃,并将各煤层的古地质时间、镜质组反射率和古地质温度三者之间的相互关系用图加以显示。对于榆神矿区的富油煤层,要升高0.02%镜质组反射率,古地质温度只需要升高3℃;而古地质时间则需要延长大约5000万a。根据煤层的最大埋深,用地表恒温15℃、鄂尔多斯盆地现地温梯度2.88℃/100 m计算得出现埋深温度仅为32.5~35.6℃,还达不到褐煤变质的临界温度。利用以正常地温为热源的煤生成镜质组反射率梯度一般低于0.06%/100 m的结论,计算得古温度梯度为8.27~8.59℃/100 m,因此重新计算的埋深温度已经升至在67.1~74.1℃。采用吴氏煤变质热动力学方程计算出最大古地质温度和平均镜质组反射率的条件下的有效受热时间6800~9600万a。According to the geological data(location,Vitrinite reflectance and average Vitrinite reflectance)of 2-2,3-1 and 5-2,the paleogeo temperature is calculated at 54.2~79.4℃by Wu's coal metamorphic thermal dynamics equation.The relationship between the paleogeo time,Vitrinite reflectance,and the paleogeo temperature of each coal seam is shown in three dimensional pictures.For oil-rich coal seam in Yushen mining area,in order to increase 0.02%Vitrinite reflectance,it is only needed to increase 3℃temperature;but it is needed to extend about 50 million years.According to the maximum buried depth of the coal seam,the calculated buried temperature is only 32.5~35.6℃,treating surface constant temperature of 15℃and geothermal gradient of the Ordos Basin of 2.88℃/100 meters.Those 32.5~35.6℃temperatures did not even reaching the critical temperature of lignite metamorphism.Using the Vitrinite reflectance gradient as 0.06%/100 meters,the calculated paleo geothermal gradient is 8.27~8.59℃/100 meters,so the buried temperature has risen up to 67.1~74.1℃.The effective heating time of the maximum paleogeo temperature and the average Vitrinite reflectance is between 68 million and 96 million years.

关 键 词：富油煤 吴氏煤变质热动力学方程 古地质温度 深成变质 古温度梯度 埋深温度 

分 类 号：TD163.1[矿业工程—矿山地质测量]