热成熟度对煤中苯并萘并呋喃分布的影响及其地球化学意义  

Effects of Thermal Maturity of Benzonaphthofurans in Coals and Its Geochemical Significance

作　　者：李佳阳 江东辉[2] 朱志立 杨鹏程[2] 张枝焕[1] LI JiaYang;JIANG DongHui;ZHU ZhiLi;YANG PengCheng;ZHANG ZhiHuan(State Key Laboratory of Petroleum Resources and Prospecting,College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;SINOPEC Shanghai Offshore Oil&Gas Company,Shanghai 200120,China;Wuxi Research Institute of Petroleum Geology,RIPEP,SINOPEC,Wuxi,Jiangsu 214216,China)

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,地球科学学院,北京102249 [2]中国石油化工股份有限公司上海海洋油气分公司勘探开发研究院,上海200120 [3]中国石化石油勘探开发研究院无锡石油地质研究所,江苏无锡214216

出　　处：《沉积学报》2023年第3期901-908,共8页Acta Sedimentologica Sinica

摘　　要：苯并萘并呋喃(BNF)是沉积有机质和原油中重要的复杂含氧多环芳烃化合物,但其在煤中的检测和鉴定还鲜有报道。通过标样相对保留时间和标准保留指数对比的色谱—质谱分析方法,对东海盆地西湖凹陷古近系、鄂尔多斯盆地石炭系—二叠系和塔里木盆地库车凹陷侏罗系等32件煤中苯并萘并呋喃系列进行了系统、准确地鉴定,并刻画了其在不同成熟度煤中的分布特征。采用量子化学计算的方法,精确精算了苯并萘并呋喃系列的热力学性质。结果显示,该系列在色谱柱(HP-5MS)上的流出顺序为:苯并[b]萘并[2,1-d]呋喃([2,1]BNF)、苯并[b]萘并[1,2-d]呋喃([1,2]BNF)、苯并[b]萘并[2,3-d]呋喃([2,3]BNF),热稳定性大小顺序为:[1,2]BNF>[2,1]BNF>[2,3]BNF。随着成熟度的增加,[1,2]BNF丰度相对于[2,1]BNF逐渐增加,提出苯并萘并呋喃比值(BNFR=[1,2]BNF/[2,1]BNF)作为成熟度参数,并建立了BNFR与镜质组反射率(Ro)的定量关系式:Rc=0.45×BNFR+0.25(0.5%<Ro<2.0%)。煤中的苯并萘并呋喃主要在后生作用阶段形成,可能是在高热演化阶段形成更稠合的多环芳烃过程的中间产物。苯并萘并呋喃比值是良好的成熟度指标,可应用于低熟—高成熟原油和烃源岩(Ⅱ~Ⅲ型干酪根)成熟度的定量评价,但该参数应用于油气运移路径示踪和油源对比时要谨慎。Benzonaphthofurans(BNFs)are important complex oxygen-heterocyclic aromatic compounds in sedimenta⁃ry organic matter and crude oils.However,few studies has been performed on their detection and identification in coals.The objective of this study was to investigate the distributions of BNFs in coals and their geochemical significance.Thirty-two coal samples were collected from Paleogene strata in the Xihu Depression,Carboniferous⁃Permian forma⁃tions in the Ordos Basin,and Jurassic stratum in the Kuqa Depression of the Tarim Basin.The BNFs were unambiguous⁃ly identified in the coals though comparisons of the relative retention time and indices of authentic standards in gas chromatography⁃mass spectrometry(GC⁃MS)analyses.The occurrence and distributions of BNFs in coals with various thermal maturities were systematically described.Density functional theory(DFT)calculation is a powerful tool for gaining further insight into molecular level phenomena in organic geochemistry.DFT calculation was conducted to de⁃termine the thermodynamic properties,i.e.,electron energy(ΔE),internal energy(ΔU),enthalpy(ΔH),and Gibbs free energy(ΔG),of the BNFs.Results suggest that the elution order of BNFs in HP-5MS chromatographic column is as follows:benzo[b]naphtho[2,1-d]furan([2,1]BNF),benzo[b]naphtho[1,2-d]furan([1,2]BNF),benzo[b]naphtho[2,3-d]furan([2,3]BNF),which agrees with previous studies.The Gibbs free energy of[2,3]BNF,[2,1]BNF,and[1,2]BNF successively decrease,suggesting that their thermodynamic stabilities have the following sequence:[1,2]BNF>[2,1]BNF>[2,3]BNF.In most coals,[2,3]BNF isomer is present at low concentrations or trace amounts.For coals with low thermal maturity(Ro<0.7%),the abundance of[2,1]BNF is relatively high and prevails over[1,2]BNF.However,the more mature coals(Ro>0.7%)contain[1,2]BNF as the dominant isomer,while[2,1]BNF occurs in rela⁃tively low abundance.The thermodynamic stability of[1,2]BNF is estimated to be higher than that of[2,1]BNF and[2,3]BNF,which is consistent with the calcu

关 键 词：煤 苯并萘并呋喃比值 量子化学计算 热稳定性 成熟度指标 

分 类 号：P618.13[天文地球—矿床学]