Migration differentiation of hydrocarbon components in the 7th member of the Triassic Yanchang Formation，central Ordos Basin

被引：0
|
作者：
Shi L. [1 ]
Fan B. [1 ]
Li Z. [1 ]
Yu Z. [2 ]
Lin Z. [1 ]
Dai X. [1 ]
机构：
[1] School of Petroleum Engineering and Environmental Engineering, Yan’an University, Shaanxi, Yan’an
[2] No. 3 Oil Extraction Factory, Qinghai Oilfield Company, PetroChina, Mangya, Qinghai
来源：
Oil and Gas Geology | 2024年 / 45卷 / 01期
关键词：
Chang 7 Member of Yanchang Formation; hydrocarbon component; migration differentiation; Ordos Basin; shale; Triassic;
D O I：
10.11743/ogg20240111
中图分类号：
学科分类号：
摘要：
The shale sequence of the 7th member of the Yanchang Formation（also referred to as the Chang 7 Member）in the Ordos Basin consists of mudstones，shales，and sandstones. To delve into the migration differentiation of shale oil components in different lithologies，we investigate the migration differentiation of typical hydrocarbon components in the central Ordos Basin. The findings show that the rocks exhibit different contents of the four group components：saturated hydrocarbons（SAT），aromatic hydrocarbons（ARO），polar nitrogen- ，sulfur- ，and oxygen-containing compounds （NSO），and asphaltenes（Asph）. Specifically，the sandstones manifest high SAT content and low NSO+Asph content. Conversely，the shales and mudstones exhibit low SAT content and high NSO+Asph content. Regarding n-alkanes，the sandstones demonstrate high nC11-15 content and low nC23-39 content，while the shales and mudstones display low nC11-15 content and high nC23-39 content. Compared to the sandstones，the shales and mudstones show more significant variations in the Pr/Ph，Pr/nC17，and Ph/nC18 ratios. These rocks manifest low C27/C29 regular sterane ratios and low Ts/Tm and Ts/ （Ts+Tm）ratios，while the sandstones show opposite trends. They demonstrate substantial variability in 22S（/ 22S+22R）ratios for C32 homohopane，in contrast to the relatively concentrated ratios for the sandstones. Besides，the sandstones are characterized by high gammacerane index values varying in a broad range，whereas the shales and mudstones exhibit the opposite trend. Notably，the shales and mudstones generally have 8β（H）-drimane/8β（H）-homodrimane ratios exceeding 1，which，however，are typically less than 1 for the sandstones. A comprehensive analysis indicates that the variations in the distributions of the various hydrocarbon group components within the source rocks can be attributed to both differential adsorption and migration differentiation. © 2024 Editorial Department of Oil and Gas Geology. All rights reserved.
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页码：157 / 168
页数：11
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共 29 条
  • [1] ILLING V C., The migration of oil and natural gas（with discussion）［J］, Journal of the Institution of Petroleum Technologists, 19, 114, pp. 229-274, (1933)
  • [2] WELTE D H., Petroleum formation and occurrence：A new approach to oil and gas exploration［M］, pp. 438-524, (1978)
  • [3] LI Chuanliang, ZHANG Jinglian, DU Zhimin, New viewpoints of the primary migration of oil and gas［J］, Earth Science Frontiers, 14, 4, pp. 132-142, (2007)
  • [4] HUANG Zhilong, MA Jian, WU Hongzhu, Et al., Fluid pressure and primary migration characteristics of shale oil of Lucaogou Formation in Malang Sag［J］, Journal of China University of Petroleum（Edition of Natural Science）, 36, 5, pp. 7-11, (2012)
  • [5] MA Zhongliang, ZHENG Lunju, ZHAO Zhongxi, Et al., Effect of fluid medium in source rock porosity on oil primary migration［J］, Petroleum Geology and Experiment, 37, 1, pp. 97-101, (2015)
  • [6] LIU Daoli, DU Zhongming, XU Xinming, Et al., The main control factors on effective Paleogene primary oil and gas migration：A comparative study of exploration results from Xijiang A and Xijiang B structural traps，Zhujiangkou Basin［J］, Marine Geology Frontiers, 33, 10, pp. 40-48, (2017)
  • [7] ZHANG Huanxu, CHEN Shijia, ZHANG Ya, Et al., Research progress of the overpressure caused by hydrocarbon generation ［J］, Bulletin of Geological Science and Technology, 37, 2, pp. 199-207, (2018)
  • [8] LI Maowen, MA Xiaoxiao, JIANG Qigui, Et al., Enlightenment from formation conditions and enrichment characteristics of marine shale oil in north America［J］, Petroleum Geology and Recovery Efficiency, 26, 1, pp. 13-28, (2019)
  • [9] STAINFORTH J G, REINDERS J E A., Primary migration of hydrocarbons by diffusion through organic matter networks，and its effect on oil and gas generation［J］, Organic Geochemistry, 16, 1/3, pp. 61-74, (1990)
  • [10] Bojiang FAN, Liang SHI, Deep-lacustrine shale heterogeneity and its impact on hydrocarbon generation，expulsion，and retention：A case study from the Upper Triassic Yanchang Formation，Ordos Basin，China［J］, Natural Resources Research, 28, 1, pp. 241-257, (2019)
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