Oil Source and Hydrocarbon Accumulation Model of Chang 8 Reservoir in Northern Pingliang Area, Ordos Basin

doi:10.7657/XJPG20250308

Abstract

Abstract:

To determine the oil source and hydrocarbon accumulation mechanism for the eighth member of the Yanchang formation (Chang 8 member) in the northern Pingliang area of the Ordos Basin, chromatography and chromatography-mass spectrometry of saturated hydrocarbon, and carbon isotope composition were combined to analyze organic geochemical properties and sources of the crude oil in the Chang 8 member. It is found that the crude oil in the Chang 8 member varies greatly in density and viscosity. Due to biodegradation, the crude oil in the Chang 8 member is characterized by high density, high viscosity, elevated Pr/nC₁₇ and Ph/nC₁₈ ratios, and relatively low abundance of rearranged hopanes. The ααα-20R steranes display an asymmetric V-shaped distribution, and the crude oil contains a high proportion of C₂₇ regular steranes, indicating that its organic precursor is primarily derived from aquatic organisms deposited in a freshwater to brackish water, weakly oxic to weakly reducing environment. The crude oil in the Chang 8 member in the Pingliang-Guoyuan area is classified as low mature to mature oil, with lower Ts/Tm, tricyclic terpane/17α(H), and 21β(H) hopane values compared to the crude oil in the Change 8 member in the Yinjiacheng area. The Chang 7 source rock in the study area has lower organic matter abundance, maturity, and development scale than those in the Qingyang area, with differences in tricyclic terpane/17α(H), and 21β(H) hopane values. By comparing the biomarkers of crude oil and source rocks, and considering the development and maturity of the source rocks, it is inferred that the crude oil in the Chang 8 member in the Pingliang-Guoyuan area is well correlated with the Chang 7 source rock in the northern Pingliang area, and it is mainly accumulated after vertical migration. In contrast, the crude oil in the Chang 8 member in the Yinjiacheng area is correlated with the Chang 7 source rock in the Qingyang area, and it is mainly accumulated after lateral transportation and migration.

Key words: Ordos Basin, Tianhuan depression, Western Margin thrust belt, Yanchang formation, Chang 8 member, oil source, accumulation mechanism

CLC Number:

TE122.1

LUO Lirong, LI Jianfeng, ZHU Jing, KONG Lingyin, BAI Chang’e, JU Yingjun, HOU Yunchao. Oil Source and Hydrocarbon Accumulation Model of Chang 8 Reservoir in Northern Pingliang Area, Ordos Basin[J]. Xinjiang Petroleum Geology, 2025, 46(3): 318-328.

Figures/Tables 12

Fig. 1.

Fig. 2.

Table 1.

Fig. 3.

Table 2.

Fig. 4.

Fig. 5.

Fig. 6.

Fig. 7.

Fig. 8.

Fig. 9.

Fig. 10.

References 33

[1]	刘显阳, 李士祥, 周新平, 等. 鄂尔多斯盆地石油勘探新领域、新类型及资源潜力[J]. 石油学报, 2023, 44(12):2070-2090. doi: 10.7623/syxb202312005
	LIU Xianyang, LI Shixiang, ZHOU Xinping, et al. New fields,new types and resources potentials of petroleum exploration in Ordos Basin[J]. Acta Petrolei Sinica, 2023, 44(12):2070-2090. doi: 10.7623/syxb202312005
[2]	惠潇, 赵彦德, 邵晓州, 等. 鄂尔多斯盆地中生界石油地质条件、资源潜力及勘探方向[J]. 海相油气地质, 2019, 24(2):14-22.
	HUI Xiao, ZHAO Yande, SHAO Xiaozhou, et al. The geological conditions,resource potential,and exploration direction of oil in Or‐dos Basin[J]. Marine Origin Petroleum Geology, 2019, 24(2):14-22.
[3]	罗安湘, 喻建, 刘显阳, 等. 鄂尔多斯盆地中生界石油勘探实践及主要认识[J]. 新疆石油地质, 2022, 43(3):254-260.
	LUO Anxiang, YU Jian, LIU Xianyang, et al. Practices and cognitions of petroleum exploration in Mesozoic,Ordos Basin[J]. Xinjiang Petroleum Geology, 2022, 43(3):254-260.
[4]	刘池洋, 王建强, 张东东, 等. 鄂尔多斯盆地油气资源丰富的成因与赋存-成藏特点[J]. 石油与天然气地质, 2021, 42(5):1012-1029.
	LIU Chiyang, WANG Jianqiang, ZHANG Dongdong, et al. Genesis of rich hydrocarbon resources and their occurrence and accumulation characteristics in the Ordos Basin[J]. Oil & Gas Geology, 2021, 42(5):1012-1029.
[5]	付金华, 董国栋, 周新平, 等. 鄂尔多斯盆地油气地质研究进展与勘探技术[J]. 中国石油勘探, 2021, 26(3):19-40.
	FU Jinhua, DONG Guodong, ZHOU Xinping, et al. Research progress of petroleum geology and exploration technology in Ordos Basin[J]. China Petroleum Exploration, 2021, 26(3):19-40. doi: 10.3969/j.issn.1672-7703.2021.03.003
[6]	邵晓州, 王苗苗, 齐亚林, 等. 鄂尔多斯盆地平凉北地区长 8 油藏特征及成藏主控因素[J]. 岩性油气藏, 2021, 33(6):59-69. doi: 10.12108/yxyqc.20210607
	SHAO Xiaozhou, WANG Miaomiao, QI Yalin, et al. Characteristics and main controlling factors of Chang 8 reservoir in northern Pingliang area,Ordos Basin[J]. Lithologic Reservoirs, 2021, 33(6):59-69. doi: 10.12108/yxyqc.20210607
[7]	齐亚林, 李涛涛, 徐龙, 等. 平凉北延长组长8段油层地质工程一体化评价[J]. 录井工程, 2021, 32(2):50-56. doi: 10.3969/j.issn.1672-9803.2021.02.010
	QI Yalin, LI Taotao, XU Long, et al. Evaluation method of geology-engineering integration for the 8th member of Yanchang formation in northern Pingliang[J]. Mud Logging Engineering, 2021, 32(2):50-56. doi: 10.3969/j.issn.1672-9803.2021.02.010
[8]	赵彦德, 邓秀芹, 齐亚林, 等. 鄂尔多斯盆地平凉北地区 M53井烃源岩地球化学特征与长8段油层油源[J]. 现代地质, 2020, 34(4):800-811.
	ZHAO Yande, DENG Xiuqing, QI Yalin, et al. Geochemical characteristics of source rocks of M53 well and Chang-8 member oilsource in Pingliangbei exploration area,Ordos Basin[J]. Geoscience, 2020, 34(4):800-811.
[9]	SU Kaiming, CHEN Shijia, HOU Yuting, et al. Geochemical characteristics,origin of the Chang 8 oil and natural gas in the southwestern Ordos Basin,China[J]. Journal of Petroleum Science and Engineering, 2021, 200:108406.
[10]	王龙, 陈培元, 孙福亭, 等. 鄂尔多斯盆地彭阳地区延长组、延安组原油地球化学特征与油源对比[J]. 海洋地质前沿, 2019, 35(12):49-55.
	WANG Long, CHEN Peiyuan, SUN Futing, et al. Geochemical characteristics of crude oil from Yanchang and Yan’an formations in Pengyang area of Ordos Basin and their implications for oil-source[J]. Marine Geology Frontiers, 2019, 35(12):49-55.
[11]	薛楠, 邵晓州, 朱光有, 等. 鄂尔多斯盆地平凉北地区三叠系长 7 段烃源岩地球化学特征及形成环境[J]. 岩性油气藏, 2023, 35(3):51-65. doi: 10.12108/yxyqc.20230305
	XUE Nan, SHAO Xiaozhou, ZHU Guangyou, et al. Geochemical characteristics and formation environment of source rocks of Triassic Chang 7 member in northern Pingliang area,Ordos Basin[J]. Lithologic Reservoirs, 2023, 35(3):51-65. doi: 10.12108/yxyqc.20230305
[12]	白杨, 张晓磊, 刚文哲, 等. 鄂尔多斯盆地平凉北地区上三叠统长8 段储层低含油饱和度油藏特征及成因[J]. 岩性油气藏, 2023, 35(3):66-75. doi: 10.12108/yxyqc.20230306
	BAI Yang, ZHANG Xiaolei, GANG Wenzhe, et al. Characteristics and genesis of Upper Triassic Chang 8 reservoir with low oil saturation in northern Pingliang area,Ordos Basin[J]. Lithologic Reservoirs, 2023, 35(3):66-75. doi: 10.12108/yxyqc.20230306
[13]	李明瑞, 侯云超, 谢先奎, 等. 鄂尔多斯盆地平凉—演武地区三叠系延长组油气成藏模式及勘探前景[J]. 石油学报, 2023, 44(3):433-446. doi: 10.7623/syxb202303003
	LI Mingrui, HOU Yunchao, XIE Xiankui, et al. Hydrocarbon accumulation mode and exploration prospect of Triassic Yanchang formation in Pingliang-Yanwu area,Ordos Basin[J]. Acta Petrolei Sinica, 2023, 44(3):433-446. doi: 10.7623/syxb202303003
[14]	张祥龙, 刘一仓, 张攀, 等. 沉积微相控制下储层分类评价及预测:以鄂尔多斯盆地环西—彭阳南段地区长 8 段为例[J]. 沉积学报, 2022, 40(2):535-546.
	ZHANG Xianglong, LIU Yicang, ZHANG Pan, et al. Reservoir classification evaluation and prediction in terms of sedimentary microfacies:A case study from Chang 8 section in Huanxi-Pengyang south section,Ordos Basin[J]. Acta Sedimentologica Sinica, 2022, 40(2):535-546.
[15]	罗丽荣, 李剑锋, 杨伟伟, 等. 鄂多斯盆地伊陕斜坡长9烃源岩特征与生烃潜力[J]. 新疆石油地质, 2022, 43(3):279-284.
	LUO Lirong, LI Jianfeng, YANG Weiwei, et al. Characteristics and hydrocarbon generation potential of Chang 9 source rocks on Yishaan slope,Ordos Basin[J]. Xinjiang Petroleum Geology, 2022, 43(3):279-284.
[16]	张才利, 刘新社, 杨亚娟, 等. 鄂尔多斯盆地长庆油田油气勘探历程与启示[J]. 新疆石油地质, 2021, 42(3):253-263.
	ZHANG Caili, LIU Xinshe, YANG Yajuan, et al. Petroleum exploration history and enlightenment of Changqing oilfield in Ordos Basin[J]. Xinjiang Petroleum Geology, 2021, 42(3):253-263.
[17]	彼得斯K E, 沃尔特斯C C, 莫尔多万J M. 生物标志化合物指南[M].2版. 张水昌,李振西译. 北京: 石油工业出版社, 2011:189-190.
	PETERS K E, WALTERS C C, MOLDOWAN J M. The biomarker guide[M]. 2nd ed. Translated by ZHANG Shuichang,LI Zhenxi. Beijing: Petroleum Industry Press, 2011:189-190.
[18]	李志军, 马学峰, 罗强, 等. 渤海湾盆地保定凹陷早熟低熟油特征及成烃机制[J]. 石油学报, 2024, 45(3):500-516. doi: 10.7623/syxb202403002
	LI Zhijun, MA Xuefeng, LUO Qiang, et al. Characteristic and hydrocarbon generation mechanism of early low mature oil in Baoding sag,Bohai Bay Basin[J]. Acta Petrolei Sinica, 2024, 45(3):500-516. doi: 10.7623/syxb202403002
[19]	刘显阳, 赵彦德, 王飞. 鄂尔多斯盆地西南部三叠系和侏罗系原油芳烃化合物特征与意义[J]. 兰州大学学报(自然科学版), 2015, 51(1):1-6.
	LIU Xianyang, ZHAO Yande, WANG Fei. Composition characteristics and significance of aromatic compounds in crude oils from Triassic and Jurassic reservoir in southwestern Ordos Basin[J]. Journal of Lanzhou University (Natural Sciences), 2015, 51(1):1-6.
[20]	包建平, 王铁冠, 周玉琦, 等. 甲基菲比值与有机质热演化的关系[J]. 江汉石油学院学报, 1992, 14(4):8-13.
	BAO Jianping, WAN Tieguan, ZHOU Yuqi, et al. The relationship between methyl phenanthrene ratios and the evolution of organic matter[J]. Journal of Jianghan Petroleum Institute, 1992, 14(4):8-13.
[21]	李梦茹, 唐友军, 杨易卓, 等. 江陵凹陷古近系新沟嘴组下段原油芳烃馏分地球化学特征及油源对比[J]. 沉积学报, 2024, 42(1):266-281.
	LI Mengru, TANG Youjun, YANG Yizhuo, et al. Correlation in crude oils from the lower member of the Paleogene Xingouzui formation in Jiangling depression[J]. Acta Sedimentologica Sinica, 2024, 42(1):266-281.
[22]	RADKE M, WELTE D H. The methyl phenanthrene index(MPI):A maturity parameter based on aromatic hydrocarbons[M]. BJOROY M.Advances in organic geochemistry 1981. New York: John Wiley and Sons, 1983:504-512.
[23]	宋海强, 刘慧卿, 王敬, 等. 鄂尔多斯盆地东南部长7段页岩油气富集主控因素[J]. 新疆石油地质, 2024, 45(1):27-34.
	SONG Haiqiang, LIU Huiqing, WANG Jing, et al. Main controlling factors of shale oil and gas enrichment in Chang 7 member,southeastern Ordos Basin[J]. Xinjiang Petroleum Geology, 2024, 45(1):27-34.
[24]	赵靖舟, 孟选刚, 韩载华. 近源成藏:来自鄂尔多斯盆地延长组湖盆东部“边缘”延长组6段原油的地球化学证据[J]. 石油学报, 2020, 41(12):1513-1526. doi: 10.7623/syxb202012006
	ZHAO Jingzhou, MENG Xuangang, HAN Zaihua. Near source hydrocarbon accumulation:Geochemical evidence of lacustrine crude oil from the Member 6 of Yanchang formation,eastern margin of Ordos Basin[J]. Acta Petrolei Sinica, 2020, 41(12):1513-1526. doi: 10.7623/syxb202012006
[25]	付金华, 李士祥, 郭芪恒, 等. 鄂尔多斯盆地陆相页岩油富集条件及有利区优选[J]. 石油学报, 2022, 43(12):1702-1716. doi: 10.7623/syxb202212003
	FU Jinhua, LI Shixiang, GUO Qiheng, et al. Enrichment conditions and favorable area optimization of continental shale oil in Ordos Basin[J]. Acta Petrolei Sinica, 2022, 43(12):1702-1716. doi: 10.7623/syxb202212003
[26]	赵文智, 卞从胜, 李永新, 等. 鄂尔多斯盆地三叠系长7₃亚段页岩有机质转化率、排烃效率与页岩油主富集类型[J]. 石油勘探与开发, 2023, 50(1):12-23. doi: 10.11698/PED.20220459
	ZHAO Wenzhi, BIAN Congsheng, LI Yongxin, et al. Organic matter transformation ratio,hydrocarbon expulsion efficiency and shale oil enrichment type in Chang 7₃ shale of Upper Triassic Yanchang formation in Ordos Basin,NW China[J]. Petroleum Exploration and Development, 2023, 50(1):12-23.
[27]	杨华, 张文正, 彭平安, 等. 鄂尔多斯盆地中生界湖相油型油的精细划分与油源对比[J]. 地球科学与环境学报, 2016, 38(2):196-205.
	YANG Hua, ZHANG Wenzheng, PENG Ping’an, et al. Oil detailed classification and oil-source correlation of Mesozoic lacustrine oil in Ordos Basin[J]. Journal of Earth Science and Environment, 2016, 38(2):196-205.
[28]	邹贤利, 陈世加, 路俊刚, 等. 鄂尔多斯盆地延长组烃源岩 17α(H)-重排藿烷的组成及分布研究[J]. 地球化学, 2017, 46(3):252-261.
	ZOU Xianli, CHEN Shijia, LU Jungang, et al. Composition and dis-tribution of 17α(H)-diahopane in the Yanchang formation source rocks,Ordos Basin[J]. Geochimica, 2017, 46(3):252-261.
[29]	孔令印, 李剑锋, 吴凯, 等. 鄂尔多斯盆地黄陵—铜川地区延安组煤矿原油成因[J]. 新疆石油地质, 2024, 45(1):35-46.
	KONG Lingyin, LI Jianfeng, WU Kai, et al. Origin of crude oil from coal mine of Yan’an formation in Huangling-Tongchuan area,Ordos Basin[J]. Xinjiang Petroleum Geology, 2024, 45(1):35-46.
[30]	楚美娟, 李士祥, 刘显阳, 等. 鄂尔多斯盆地延长组长8油层组成藏机理及成藏模式[J]. 沉积学报, 2013, 31(4):683-692.
	CHU Meijuan, LI Shixiang, LIU Xianyang, et al. Mechanism and model of petroleum accumulation in Chang 8 member of Yanchang formation,Ordos Basin[J]. Acta Sedimentologica Sinica, 2013, 31(4) :683-692.
[31]	张晓磊, 唐颖, 李卓奕, 等. 鄂尔多斯盆地西南缘延长组长 8段低充注油藏成藏模式:以环西—彭阳地区为例[J]. 西安石油大学学报(自然科学版), 2023, 38(1):31-44.
	ZHANG Xiaolei, TANG Ying, LI Zhuoyi, et al. Hydrocarbon accumulation patterns of Chang 8 low-charging oil reservoirs in southwestern margin of Ordos Basin:Taking Huanxi-Pengyang area as an example[J]. Journal of Xi’an Shiyou University (Natural Science Edition), 2023, 38(1):31-44.
[32]	邵晓舟. 鄂尔多斯盆地平凉北地区长8低含油饱和度油藏成藏机理研究[D]. 成都: 成都理工大学, 2023.
	SHAO Xiaozhou. Study on the hydrocarbon accumulation mechanism of Chang 8 low oil saturation reservoir in the northern Pingliang area,Ordos Basin[D]. Chengdu: Chengdu University of Technology, 2023.
[33]	曹晶晶, 刚文哲, 杨尚儒, 等. 鄂尔多斯盆地西南缘平凉地区长 8 油藏油源对比及油气充注特征[J]. 天然气地球科学, 2024, 35(1):149-163. doi: 10.11764/j.issn.1672-1926.2023.06.012
	CAO Jingjing, GANG Wenzhe, YANG Shangru, et al. Oil-source correlation and hydrocarbon charging characteristics of Chang 8 reservoir in the Pingliang area,southwestern Ordos Basin[J]. Natural Gas Geoscience, 2024, 35(1):149-163. doi: 10.11764/j.issn.1672-1926.2023.06.012

地区	井名	密度/（g·cm^-3）	黏度/（mPa·s）	饱和烃含量/%	芳香烃含量/%	非烃含量/%	沥青质含量/%	饱和烃/芳香烃
殷家城地区	A5井	0.803 2	3.935	72.97	16.85	4.68	1.35	4.33
殷家城地区	A7井	0.832 5	4.249	68.65	14.74	4.17	1.69	4.66
彭阳地区	B1井	0.849 5	5.160	67.59	18.15	5.74	1.30	3.72
彭阳地区	C5井	0.813 6	2.375	70.22	18.00	4.92	2.04	3.90
平凉— 郭塬地区	C77井	0.888 6	20.223	58.84	21.92	5.95	5.71	2.68
	C20井	0.894 9	20.114	59.80	17.65	6.53	4.27	3.39
	C22井	0.898 2	24.487	59.54	17.92	19.65	4.62	3.32
	C10井	0.873 0	8.116	51.96	22.47	7.22	3.92	3.11
	C67井	0.869 7	10.692	62.38	19.31	17.82	3.96	3.23
	D13井	0.880 9	9.759	61.28	21.31	6.41	4.68	2.88
	D6井	0.833 3	9.099	52.45	12.25	17.65	17.65	4.28

原油类型	井名	Pr/Ph	Pr/nC₁₇	Ph/nC₁₈	OEP	CPI	C21^-/C 21⁺
正常原油	A7井	1.44	0.32	0.24	1.08	1.14	3.32
	C34井	1.13	0.32	0.30	1.22	1.12	1.65
	C39井	1.16	0.33	0.30	1.17	1.10	1.81
	C40井	1.13	0.32	0.30	1.16	1.09	1.90
	B1井	1.21	0.28	0.25	1.05	1.23	2.40
	C10井	1.41	0.34	0.25	1.08	1.18	2.30
	D13井	1.22	0.34	0.28	1.06	1.17	1.23
	D6井	1.30	0.33	0.26	1.12	1.05	1.82
生物降解原油	C20井	1.00	15.38	10.00	1.61	0.62	1.27
	C22井	1.21	1.08	0.91	1.06	1.31	2.03
	C77井	1.20	0.63	0.57	1.12	1.25	1.30