鄂尔多斯盆地长7段烃源岩有机地球化学特征
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摘要
根据烃源岩露头分析结果,结合岩心样品的S、同位素、生物标志化合物等测试数据,研究长7段优质烃源岩的地球化学特征及发育环境。长7段泥页岩的有机质丰度较高,氯仿沥青"A"的均值大于0.1%,干酪根类型为偏腐泥型的有机质,处于成熟阶段。其中,干酪根δ~(13)C多分布于-29.5‰～-29.0‰;饱和烃中正构烷烃为单峰型分布,为前峰型的特征;甾烷ααα20R构型的C_(27)、C_(28)、C_(29)呈近"V"型或"L"型分布,轻重烷烃∑C_(21)~-/∑C_(22)~+比值与(nC_(21)+nC_(22))/(nC_(28)+nC_(29))比值均较高,孕甾烷、升孕甾烷及C_(27)—C_(29)规则甾烷含量较高。这些特征均表明,生源母质以低等淡水中水生生物藻类为主。长7段烃源岩沉积期为典型的还原环境,S含量基本小于6%,Pr/Ph平均值为1,Pr/nC_(17)和Ph/nC_(18)比值均小于1,伽玛蜡烷/C_(30)藿烷的平均值为0.1左右。
This essay aims to study Chang 7 resource rocks' geochemistry characteristics and development environment by analyzing the outcrops,S of the samples,isotopes,biomarkers,etc. The abundance of organic matter in shale is high and the average value of chloroform asphalt "A"is greater than 0. 1%. Kerogen type is partial rotten mud type organic matter at the maturing stage. δ~(13)C of kerogen distributes mainly from-29. 5‰ to-29. 0‰; n-alkanes of saturated hydrocarbon are characterized as single-apex,forward apex type. Sterane ααα20R C_(27),C_(28) and C_(29) distribute similar to the shape of "V"or "L". There are relatively high ration of ∑C_(21)~-/∑C_(22)~+ and( nC_(21)+nC_(22))/( nC_(28)+ nC_(29)),and rather high contents of pregnane and C_(27)— C_(29) regular steranes. These features show that source materials are mainly lower hydrobiont,such as algae. On the other hand,the contents of S are usually less than 6%; the average values of Pr/Ph is 1; the ratios of Pr/nC_(17) and Ph/nC_(18) are generally less than 1; the average value of gamma cerane/C_(30) hopance is about 0. 1. These characteristics indicate the resource rocks are developed in the reducing environment.
This essay aims to study Chang 7 resource rocks' geochemistry characteristics and development environment by analyzing the outcrops,S of the samples,isotopes,biomarkers,etc. The abundance of organic matter in shale is high and the average value of chloroform asphalt "A"is greater than 0. 1%. Kerogen type is partial rotten mud type organic matter at the maturing stage. δ~(13)C of kerogen distributes mainly from-29. 5‰ to-29. 0‰; n-alkanes of saturated hydrocarbon are characterized as single-apex,forward apex type. Sterane ααα20R C_(27),C_(28) and C_(29) distribute similar to the shape of "V"or "L". There are relatively high ration of ∑C_(21)~-/∑C_(22)~+ and( nC_(21)+nC_(22))/( nC_(28)+ nC_(29)),and rather high contents of pregnane and C_(27)— C_(29) regular steranes. These features show that source materials are mainly lower hydrobiont,such as algae. On the other hand,the contents of S are usually less than 6%; the average values of Pr/Ph is 1; the ratios of Pr/nC_(17) and Ph/nC_(18) are generally less than 1; the average value of gamma cerane/C_(30) hopance is about 0. 1. These characteristics indicate the resource rocks are developed in the reducing environment.
引文
[1]姚泾利,邓秀芹,赵彦德,等.鄂尔多斯盆地延长组致密油特征[J].石油勘探与开发,2013,40(2):150-158.
[2]庞正炼,邹才能,陶士振,等.中国致密油形成分布与资源潜力评价[J].中国工程科学,2012,14(7):60-67.
[3]李德生.重新认识鄂尔多斯盆地油气地质学[J].石油勘探与开发,2004,31(6):1-7.
[4]杨华,张文正.论鄂尔多斯盆地长7段优质油源岩在低渗透油气成藏富集中的主导作用:地质地球化学特征[J].地球化学,2005,34(2):147-154.
[5]张文正,杨华,李剑锋,等.论鄂尔多斯盆地长7段优质油源岩在低渗透油气成藏富集中的主导作用:强生排烃特征及机理分析[J].石油勘探与开发,2006,33(3):289-293.
[6]张文正,杨华,杨奕华,等.鄂尔多斯盆地长7优质烃源岩的岩石学、元素地球化学特征及发育环境[J].地球化学,2008,37(1):59-64.
[7]邓南涛,张枝焕,鲍志东.鄂尔多斯盆地南部延长组有效烃源岩地球化学特征及其识别标志[J].中国石油大学学报(自然科学版),2013,37(2):135-145.
[8]付金华,邓秀芹,张晓磊,等.鄂尔多斯盆地三叠系延长组深水砂岩与致密油的关系[J].古地理学报,2013,15(5):624-634.
[9]李薇,刘洛夫,王艳如,等.应用测井数据计算泥页岩厚度:以鄂尔多斯盆地延长组长73油层为例[J].中国石油勘探,2012(5):32-35.
[10]王艳如,刘洛夫,杨丽萍,等.鄂尔多斯盆地长7烃源岩有机碳测井评价[J].岩性油气藏,2013,25(4):78-82.
[11]张文正,杨华,解丽琴,等.湖底热水活动及其对优质烃源岩发育的影响:以鄂尔多斯盆地长7烃源岩为例[J].石油勘探与开发,2010,37(4):424-429.
[12]孟仟祥,房嬛,徐永昌,等.柴达木盆地石炭系烃源岩和煤岩生物标志物特征及其地球化学意义[J].沉积学报,2004,22(4):729-736.
[13]傅家谟,盛国英,许家友,等.应用生物标志化合物参数判识古沉积环境[J].地球化学,1991,3(1):1-12.
[14]张枝焕,杨藩,李东明,等.中国新生界咸水湖相烃源岩和原油生物标志物组合特征[J].沉积学报,1998,16(3):119-123.
[15]赵孟军,张水昌. 17α(H)—重排藿烷在塔里木盆地中的指相意义[J].石油勘探与开发,2001,28(1):30-31.
[2]庞正炼,邹才能,陶士振,等.中国致密油形成分布与资源潜力评价[J].中国工程科学,2012,14(7):60-67.
[3]李德生.重新认识鄂尔多斯盆地油气地质学[J].石油勘探与开发,2004,31(6):1-7.
[4]杨华,张文正.论鄂尔多斯盆地长7段优质油源岩在低渗透油气成藏富集中的主导作用:地质地球化学特征[J].地球化学,2005,34(2):147-154.
[5]张文正,杨华,李剑锋,等.论鄂尔多斯盆地长7段优质油源岩在低渗透油气成藏富集中的主导作用:强生排烃特征及机理分析[J].石油勘探与开发,2006,33(3):289-293.
[6]张文正,杨华,杨奕华,等.鄂尔多斯盆地长7优质烃源岩的岩石学、元素地球化学特征及发育环境[J].地球化学,2008,37(1):59-64.
[7]邓南涛,张枝焕,鲍志东.鄂尔多斯盆地南部延长组有效烃源岩地球化学特征及其识别标志[J].中国石油大学学报(自然科学版),2013,37(2):135-145.
[8]付金华,邓秀芹,张晓磊,等.鄂尔多斯盆地三叠系延长组深水砂岩与致密油的关系[J].古地理学报,2013,15(5):624-634.
[9]李薇,刘洛夫,王艳如,等.应用测井数据计算泥页岩厚度:以鄂尔多斯盆地延长组长73油层为例[J].中国石油勘探,2012(5):32-35.
[10]王艳如,刘洛夫,杨丽萍,等.鄂尔多斯盆地长7烃源岩有机碳测井评价[J].岩性油气藏,2013,25(4):78-82.
[11]张文正,杨华,解丽琴,等.湖底热水活动及其对优质烃源岩发育的影响:以鄂尔多斯盆地长7烃源岩为例[J].石油勘探与开发,2010,37(4):424-429.
[12]孟仟祥,房嬛,徐永昌,等.柴达木盆地石炭系烃源岩和煤岩生物标志物特征及其地球化学意义[J].沉积学报,2004,22(4):729-736.
[13]傅家谟,盛国英,许家友,等.应用生物标志化合物参数判识古沉积环境[J].地球化学,1991,3(1):1-12.
[14]张枝焕,杨藩,李东明,等.中国新生界咸水湖相烃源岩和原油生物标志物组合特征[J].沉积学报,1998,16(3):119-123.
[15]赵孟军,张水昌. 17α(H)—重排藿烷在塔里木盆地中的指相意义[J].石油勘探与开发,2001,28(1):30-31.