摘要
为了研究西湖凹陷原油轻烃地球化学特征及区分油气来源,利用气相色谱仪分析西湖凹陷16个原油样品,采用庚烷值与异庚烷值对原油成熟度进行划分.结果表明:西湖凹陷原油富含芳烃和环烷烃,直链烷烃含量低,以陆源有机质贡献为主;原油经历较为明显的蒸发分馏作用;异庚烷值与正庚烷值分别介于0.69~1.90和11.5~21.9之间,原油处于成熟油阶段.西湖凹陷不同地区的原油在轻烃组分上存在明显差异,指示原油母质来源的不同.同时,利用原油C7轻烃三角图和Halpern C7星状图,并结合原油碳同位素与芳烷指数,可以进一步区分各地区原油的母质来源.平湖地区原油主要为来自平湖组煤与泥岩的混合贡献,黄岩地区原油主要为花港组与平湖组泥岩贡献.
Coal and mudstone source rocks were widely developed in the Xihu sag of east China sea basin,where oil and gas were mainly sourced from two types of source rocks.In order to study the light hydrocarbon geochemical characteristics of crude oil in Xihu sag and the source of oil and gas,16 crude oil samples in Xihu sag were analyzed by gas chromatography.The results show that the oils in Xihu sag have a relatively high content of aromatics and naphthenic hydrocarbon while a low content of straight chain alkanes,indicating that a great contribution from the terrestrial organic matters was made.The oils have obviously experienced the evaporative fractionation;the thermal maturity of oils is at the mature stage according to the isoheptane value and heptane value are between 0.69%~1.90% and 11.5%~21.9% respectively.The oils from different regions of Xihu sag have significant differences in light hydrocarbon components,indicating the different original source of oils.By means of oils C7 light hydrocarbon triangular diagram and the Halpern C7 star correlation diagram,combining with oil carbon isotope and aralkyl index,the original source of oils in various regions can be further distinguished.From all analyses above,it is concluded that the oils in Pinghu area were main from coal mixed with mudstone source rocks of Pinghu formation,and the oils in Huangyan area were mainly contributed from the Huagang and Pinghu mudstone measures.
引文
[1]Schaefer R G.Analysis of trace amounts of hydrocarbons(C2-C8)from rocks and crude oils samples and its application in petroleum geochemistry[J].Physics and Chemistry of the Earth,1980,12:149-156.
[2]Leythaeuser D,Schaefer R G,Cornford C,et al.Generation and migration of light hydrocarbon(C2-C7)in sedimentary basins[J].Organic Geochemistry,1979,14(1):191-204.
[3]Snowdon L R.Immature oil and condensate-modification of hy-drocarbon generation model for terrestrial organic matter[J].AAPG Bulletin,1982,66(6):775-788.
[4]Thompson K F M.Fractionated aromatic petroleum and the generation of gas-condensates[J].Org.Geochem,1987,11(6):573-590.
[5]Hunt J M.Generation and migration of light hydrocarbons[J].Science,1984,226:1265-1270.
[6]林壬子.轻烃技术在油气勘探中的应用[M].武汉:中国地质大学出版社,1990:3-4.Lin Renzi.Application of light hydrocarbon technology in oil and gas exploration[M].Wuhan:China University of Geosciences Press,1990:3-4.
[7]戴金星.利用轻烃鉴别煤成气和油型气[J].石油勘探与开发,1993,20(5):26-32.Dai Jinxing.Identification of coal formed gas and oil type gas by light hydrocarbons[J].Petroleum Exploration and Development,1993,20(5):26-32.
[8]程克明,金伟明,何忠华,等.陆相原油及凝析油的轻烃单体组成特征及地质意义[J].石油勘探与开发,1987,14(1):34-43.Cheng Keming,Jin Weiming,He Zhonghua,et al.Composition characteristics of light hydrocarbons in continental oil and condensate and their geological significance[J].Petroleum Exploration and Development,1987,14(1):34-43.
[9]王振平,王子文,王文广.松辽盆地阿拉新—二站地区轻烃垂向迁移规律研究[J].大庆石油学院学报,1991,15(4):9-16.Wang Zhenping,Wang Ziwen,Wang Wenguang.Study of the vertical migration of the light hydrocarbon of the Arlaxing-Erzhan area in the Songliao basin[J].Journal of Daqing Petroleum Institute,1991,15(4):9-16.
[10]赵锡嘏,付晓泰,王振平,等.氯仿“A”分析新方法及C7以上正构烷烃地化指标[J].大庆石油学院学报,1996,20(1):28-32.Zhao Xigu,Fu Xiaotai,Wang Zhengpin,et al.New method for determination of chloroform"A"and the geochemistry indicator of>nC7:Normal paraffin hydrocarbons[J].Journal of Daqing Petroleum Institute,1996,20(1):28-32.
[11]陈涛,侯读杰,米巨磊,等.白云凹陷原油气洗作用[J].东北石油大学学报,2015,39(3):60-66.Chen Tao,Hou Dujie,Mi Jvlei,et al.Study on gas washing of crude oils in Baiyun sag[J].Journal of Northeast Petroleum University,2015,39(3):60-66.
[12]沈忠民,姜敏,刘四兵,等.四川盆地陆相天然气成因类型划分与对比[J].石油实验地质,2010,32(6):560-565.Shen Zhongmin,Jiang Min,Liu Sibing,et al.Partition and contrast on genetic type of continetal natural gas in the Sichuan basin[J].Petroleum Geology&Experiment,2010,32(6):560-565.
[13]高丽丽,张敏,赵红静,等.松辽盆地南部梨树断陷天然气轻烃地球化学研究[J].天然气地球科学,2011,22(4):709-714.Gao Lili,Zhang Min,Zhao Hongjing,et al.Geochemical characteristics of light hydrocarbon in natural gas from Lishu fault depression in Songliao basin[J].Natural Gas Geoscience,2011,22(4):709-714.
[14]侯读杰,冯子辉.油气地球化学[M].北京:石油工业出版社,2011:82-87.Hou Dujie,Feng Zihui.Petroleum Geochemistry[M].Beijing:Petroleum Industry Press,2011:82-87.
[15]贾健谊,须雪豪,孙伯强.东海西湖凹陷原油与天然气的地球化学特征[J].海洋石油,2000,20(2):1-7.Jia Jianyi,Xu Xuehao,Sun Boqiang.Oil/gas geochemical character in Xihu trough of the east China sea[J].Offshore Oil,2000,20(2):1-7.
[16]魏恒飞,陈践发,陈晓东,等.西湖凹陷平湖组滨海型煤系烃源岩发育环境及其控制因素[J].中国地质,2013,40(2):487-497.Wei Hengfei,Chen Jianfa,Chen Xiaodong,et al.The controlling factors and sedimentary environment for developing coastal coalbearing source rock of Pinghu formation in Xihu depression[J].Geology in China,2013,40(2):487-497.
[17]张银国.东海西湖凹陷花港组油气地质条件与油气分布规律[J].石油实验地质,2010,32(3):223-226.Zhang Yinguo.Petroleum geology and hydrocarbon distribution pattern of huagang formation in the Xihu sag of the east China sea[J].Petroleum Geology&Experiment,2010,32(3):223-226.
[18]杨彩虹,曾广东,李上卿,等.东海西湖凹陷平北地区断裂发育特征与油气聚集[J].石油实验地质,2014,36(1):64-69.Yang Caihong,Zeng Guangdong,Li Shangqing,et al.Fault development characteristics and hydrocarbon accumulation in Pingbei area of Xihu sag,east China sea[J].Petroleum Geology&Experiment,2014,36(1):64-69.
[19]王国纯.东海盆地油气勘探焦点问题探讨[J].中国海上油气(地质),2003,17(1):31-34.Wang Guochun.A discussion on some focal problems of petroleum exploration in east China sea basin[J].China Offshore Oil and Gas(Geology),2003,17(1):31-34.
[20]胡芬,叶加仁,刘俊海.东海西湖凹陷平湖构造带油气运聚特征[J].海洋地质与第四纪地质,2003,23(1):95-102.Hu Fen,Ye Jiaren,Liu Junhai.Characteristics of oil and gas migration and accumulation in the Pinghu structural belt,Xihu depression,east China sea[J].Marine Geology&Quaternary Geology,2003,23(1):95-102.
[21]李上卿,李纯洁.东海西湖凹陷油气资源分布及勘探潜力分析[J].石油实验地质,2003,25(6):721-728.LI Shangqing,LI Chunjie.Analysis on the petroleum resource distribution and exploration potential of the Xihu depression,the east China sea[J].Petroleum Geology&Experiment,2003,25(6):721-728.
[22]王培荣,徐冠军,张大江,等.常用轻烃参数正、异庚烷值应用中的问题[J].石油勘探与开发,2010,37(1):121-128.Wang Peirong,Xu Guanjun,Zhang Dajiang,et al.Problems with application of heptane and soheptane values as light hydrocarbon parameters[J].Petroleum Exploration and Development,2010,37(1):121-128.
[23]苏奥,陈红汉,王存武,等.东海盆地西湖凹陷油气成因及成熟度判别[J].石油勘探与开发,2013,40(5):521-527.Su Ao,Chen Honghan,Wang Cunwu,et al.Genesis and maturity identification of oil and gas in the Xihu sag,east China sea basin[J].Petroleum Exploration and Development,2013,40(5):521-527.
[24]唐友军,张坤,胡森清,等.西湖凹陷平湖斜坡带原油轻烃地球化学特征[J].石油天然气学报,2014,36(9):28-33.Tang youjun,Zhang kun,Hu senqing,et al.Geochemical characteristics of light hydrocarbon in Pinghu slope of Xihu sag[J].Journal of Oil and Gas Technology,2014,36(9):28-33.
[25]Mango F D.The origin of light hydrocarbon in petroleum:Ring preference in the closure of carbocyclic rings[J].Geochimica et Cosmochimica Acta,1994,58(2):895-901.
[26]Bement W O,Levey R A,Mango F D.The temperature of oil generation as defined with C7chemistry maturity parameter(2,4-DMP/2,3-DMP)[M].Donostian-San Sebastian:European Association of Organic Geochemists,1995:505-507.
[27]唐友军,王铁冠.原油生成温度计算的理论与实践[J].矿物岩石地球化学通报,2007,26(3):218-220.Tang Youjun,Wang Tieguan.Theoretical calculation of oil Generation temperature and its application[J].Bulletin of Mineralogy,Petrology and Geochemistry,2007,26(3):218-220.
[28]胡惕麟,戈葆雄,张义刚,等.源岩吸附烃和天然轻烃指纹参数的开发和应用[J].石油实验地质,1990,12(4):375-393.Hu Tilin,Ge Baoxiong,Zhang Yigang,et al.The development and application of finigerprint paramenters for hydrocarbons absorbed by source rocks and light hydrocarbons in natural gas[J].Petroleum Geology&Experiment,1990,12(4):375-393.
[29]梁婉如,张敏,赵红静,等.吐哈盆地原油轻烃地球化学特征[J].天然气地球科学,2009,20(5):763-767.Liang Wanru,Zhang Min,Zhao Hongjing,et al.Geochemical characteristics of light hydrocarbons in Tuha basin[J].Natural Gas Geoscience,2009,20(5):763-767.
[30]Halpern H I.Development and applications of light-hydrocarbon-based star diagrams[J].AAPG Bulletin,1995,79:801-815.
[31]Banga T,Capuano R M,Bissada K K.Petroleum generation in the southeast texas basin:Implications for hydrocarbon occurrence at the south liberty salt dome[J].AAPG Bulletin,2001,95(7):1257-1291.
[32]龚德瑜,李明,李启明,等.塔里木盆地乌什凹陷原油地球化学特征及油源分析[J].天然气地球科学,2014,25(1):62-69.Gong Deyu,Li Ming,Li Qiming,et al.Geochemical characteristics and origins of the oils in Wushi sag,Tarim basin[J].Natural Gas Geoscience,2014,25(1):62-69.
[33]张晓宝,王琪.吐哈盆地煤成油的同位素地球化学证据[J].新疆地质,1998,16(4):359-366.Zhang Xiaobao,Wang Qi.Evidence of isotope geochmistry of coal-generated oil from Turpan-hami basin[J].Xinjiang Geology,1998,16(4):359-366.
[34]李林,陈世加,杨迪生,等.准噶尔盆地滴南凸起东段油气成因及来源[J].石油实验地质,2013,35(5):480-486.Li Lin,Chen Shijia,Yang Disheng,et al.Hydrocarbon origin and source in east section of Dinan salient of Junggar basin[J].Petroleum Geology&Experiment,2013,35(5):480-486.
[35]丁勇,贾存善,邵志兵.巴楚—麦盖提地区主要油气藏原油地球化学特征及油源探讨[J].石油实验地质,2013,35(6):683-688.Ding Yong,Jia Cunshan,Shao Zhibing.Geochemical features and sources of crude oils in Bachu-Maigaiti area[J].Petroleum Geology&Experiment,2013,35(6):683-688.
[36]段毅,彭德华,张晓宝,等.柴达木盆地原油碳同位素组成的主控因素与成因类型[J].沉积学报,2003,21(2):355-358.Duan Yi,Peng Dehua,Zhang Xiaobao,et al.Main controlling factors and genetic types of carbon isotopic compositions for crude oils from the Qaidam basin,China[J].Acta Sedimentologica Sinica,2006,18(3):161-167.
[37]米敬奎,张水昌,陈建平,等.塔北地区原油碳同位素组成特征及影响因素[J].石油勘探与开发,2010,37(1):21-25.Mi Jingkui,Zhang Shuichang,Chen Jianping,et al.Carbon isotopic compositions and effect factors of oil from northern Tarim basin[J].Petroleum Exploration and Development,2010,37(1):21-25.
[38]张云献,沈忠民,王英,等.成熟凝析油色—质谱分析及在石油地质中的应用[J].石油实验地质,2007,29(5):516-521.Zhang Yunxian,Shen Zhongmin,Wang Ying,et al.GC-MS analysis of mature condensate oil and its application in petroleum geology[J].Petroleum Geology&Experiment,2007,29(5):516-521.