AN INVESTIGATION ON THE GEOCHEMICAL CHARACTERISTICS OF CRUDE OIL FROM WENLIU AREA IN THE DONGPU SAG, BOHAI BAY BASIN
-
摘要: 对东濮凹陷文留地区原油样和油砂样进行了族组分、碳同位素、饱和烃色谱—质谱实验分析,结果表明,文留地区沙河街组原油与含油砂岩抽提物的饱和烃含量在38.3%-79.3%;原油碳同位素值分布于-27.0‰～-28.0‰,饱和烃碳同位素值在-27.4‰～-28.7‰,族组分之间的碳同位素分馏效应较小;多数样品Pr/Ph小于0.5,具有明显的植烷优势;αααC2920R/20(R+S),C29ββ/(αα+ββ)参数显示处于低熟状态;甾烷系列中C27含量略占优势,重排甾烷含量与成熟度相关,随样品成熟度增高,重排甾烷/规则甾烷值增大,低熟油样品的重排甾烷/规则甾烷值小于0.3。分布在中央隆起带文西断层与文东断层之间地区的样品,其γ-蜡烷含量较高,γ-蜡烷/C30藿烷分布于0.40～0.99,γ-蜡烷/H3122S.分布于2.11～4.15,反映了陆相咸水湖相原油特征。分布于文东断层以东的原油样品γ-蜡烷含量低,γ-蜡烷/C30藿烷分布于0.05～0.15,γ-蜡烷/H3122S分布于0.16～0.28,反映了低盐度的淡水—微咸水相原油特征。Abstract: The group composition and carbon isotope of oil,chromatogram and mass spectrum of saturation hydrocarbon in the source rocks and crude oil from Wenliu area in Dongpu Sag,Bohai Bay Basin were analyzed.The studying results show that the crude oil in the Shahejie Formation was mainly immature.The content of saturation hydrocarbon in the samples is 38.3%～79.3%.The carbon isotope of group composition of crude oil is-27.4‰～-28.7‰,and the fractionation effect of the carbon isotope of group composition is not obvious.There is predominance of phytane to pristane,and the ratio of pristane to phytane is lower than 0.5 in most samples.For the most samples,the values of αααC2920R/20(R+S) and C29ββ/(αα+ββ) are lower than 0.40,the content of diasteranes is low,and the sterane of C27 is predominance in the series of steranes.The ratio of diasteranes to regsteranes is related to the maturity of samples.High maturity is correspond to high value of the ratio.For the samples distributing between the Wendong fault and Wenxi fault,the content of Gammacerance is high,the ratio of gamma-cerance to C30hopanes is 0.40～0.99,the ratio of gammacerance to HC3122S is 2.11～4.15 and the geochemical characteristics demonstrated that they formed in the salt lake facies sedimentary environment.For the samples located in the east of Wendong fault,the content of Gammacerance was low,the ratio of gammacerance to C30 hopanes is 0.05～0.15,the ratio of gammacerance to HC3122S is 0.16～0.28,and the geochemistry characteristics demonstrated that they formed in the sedimentary environment of low salty.
-
Key words:
- biomarker /
- immature oil /
- saline lake /
- Dongpu Sag /
- Bohai Bay Basin
-
[1] Hanson A D,Riffs B D,Zinniker D,et al.Upper Oligocene lacustrine source rocks and petroleum systems of the northern Qaidam basin,northwest Chinal,J].AAPG Bull,2001,85(4):601～619 [2] 妥进才,邵宏舜,黄杏珍.盐湖相生油岩中某些地球化学参数与沉积环境的关系[J].沉积学报,1994,12(3):114～119 [3] 朱扬明,苏爱国,梁狄刚等.柴达木盆地西部第三系咸水湖相原油地球化学特征[J].地质科学,2004,39(4):475～485 [4] 朱扬明,苏爱国,梁狄刚等.柴达木盆地成湖相生油岩正构烷烃分布特征及其成因[J].地球化学,2003,32(2):117～123 [5] 段毅,王智平,张辉等.柴达木盆地原油烃类地球化学特征[J].石油实验地质,2004,26(4):359～364 [6] 朱光有,金强,戴金星等.东营凹陷沙四中亚段盐湖相烃源岩研究[J].高校地质学报,2004,lO(2):257～266 [7] 朱光有,金强,张善文等.渤南洼陷盐湖-咸水湖相沉积组合及其油气聚集[J].矿物学报,2004,24(1):25～30 [8] 张枝焕,曾艳涛,张学军等.渤海湾盆地沾化凹陷渤南洼陷原油地球化学特征及成藏期分析[J].石油实验地质,2006,28(1):56～58 [9] 林又玲,吴贤涛,潘结南等.东濮凹陷老第三系沙河街组盐类沉积模式新见[J].古地理学报,2000,2(4):66～75 [10] 陈发亮,朱晖,李绪涛等.东濮凹陷下第三系沙河街组层序地层划分及盐岩成因探讨[J].沉积学报,2000,18(3):386～388 [11] 金强,黄醒汉.东濮凹陷早第三纪盐湖成因探讨[J].华东石油学院学报,1985,(1):1～13 [12] 郑鸿稳.东濮凹陷下第三系层序地层模式[J].石油学报,2002,23(4):24～28 [13] Poppet B N,Laws E A,Bidigare R R,et al.Effect of phytoplankton cell geometry on carbon isotopic fractionation[J].Geochim et Cosmochim Acta,1998,62(1):69～77 [14] 徐永昌,沈平,刘文汇等.未熟—低熟油的同位素组成特征及判识标志[J].科学通报,2001,46(10):867 ～872 [15] 蔡勋育,朱扬明.川东南官渡构造中侏罗统原油地球化学特征及油源[J].石油实验地质,2006,28(4):380～385 [16] 史继扬,汪本善.苏北盆地生油岩中甾、萜的地球化学特征和我国东部低成熟的生油岩与原油[J].地球化学,1985,14(1):80～88 -
点击查看大图
计量
- 文章访问数: 806
- HTML全文浏览量: 38
- PDF下载量: 368
- 被引次数: 0
下载:
苏公网安备32021102000780号