Sedimentary and geochemical characteristics of the Triassic Chang 7 Member shale in the Southeastern Ordos Basin, Central China

Abstract The Ordos Basin is the largest petroliferous basin in China, where the Chang 7 Member shale serves as the major source rock in the basin, with an area of more than 100,000 km2. So far, sedimentary and geochemical characterizations have rarely been conducted on the shale in shallow (< 100...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Jing-Wei Cui, Ru-Kai Zhu, Zhong Luo, Sen Li
Formato:	article
Lenguaje:	EN
Publicado:	KeAi Communications Co., Ltd. 2019
Materias:	Ordos Basin Chang 7 Member oil Organic-rich shale Sedimentary characteristics Geochemical characteristics Science Q Petrology QE420-499
Acceso en línea:	https://doaj.org/article/c0f70321e0bd4f3190361437258614be
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:c0f70321e0bd4f3190361437258614be
record_format	dspace
spelling	oai:doaj.org-article:c0f70321e0bd4f3190361437258614be2021-12-02T09:02:57ZSedimentary and geochemical characteristics of the Triassic Chang 7 Member shale in the Southeastern Ordos Basin, Central China10.1007/s12182-019-0307-91672-51071995-8226https://doaj.org/article/c0f70321e0bd4f3190361437258614be2019-03-01T00:00:00Zhttp://link.springer.com/article/10.1007/s12182-019-0307-9https://doaj.org/toc/1672-5107https://doaj.org/toc/1995-8226Abstract The Ordos Basin is the largest petroliferous basin in China, where the Chang 7 Member shale serves as the major source rock in the basin, with an area of more than 100,000 km2. So far, sedimentary and geochemical characterizations have rarely been conducted on the shale in shallow (< 1000 m) areas in the southeastern part of the basin, but such characterizations can help identify the genesis of organic-rich shale and promote the prediction and recovery of shale oil. In this paper, several outcrop sections of the Chang 7 Member in the Tongchuan area were observed and sampled, and sedimentary and geochemical characterizations were conducted for the well-outcropped YSC section. The study results show that the Chang 7 Member shale is widely distributed laterally with variable thickness. The organic-rich shale is 7–25 m thick in total and exhibits obvious horizontal variation in mineral composition. In the eastern sections, the shale contains organic matter of Type II2–III and is low in thermal maturity, with high clay mineral content, low K-feldspar content, and no pyrite. In the western sections, the shale contains Type II1 organic matter and is low in thermal maturity, with high clay mineral, K-feldspar, and pyrite contents. The YSC section reveals three obvious intervals in vertical mineral composition and organic abundance. The Chang 7 Member organic-rich shale (TOC > 10%) contains mainly sapropelite and liptinite, with Type II kerogen. It is generally characterized by a hydrocarbon potential of more than 70 mg/g, low maturity, and shallow–semideep lacustrine facies. In the western sections, the shale, still in a low maturity stage, has a higher hydrocarbon potential and is optional for shale oil recovery. However, the Chang 7 Member shale in the study area is highly heterogeneous and its shale oil recovery is practical only in the organic-rich intervals.Jing-Wei CuiRu-Kai ZhuZhong LuoSen LiKeAi Communications Co., Ltd.articleOrdos BasinChang 7 Member oilOrganic-rich shaleSedimentary characteristicsGeochemical characteristicsScienceQPetrologyQE420-499ENPetroleum Science, Vol 16, Iss 2, Pp 285-297 (2019)
institution	DOAJ
collection	DOAJ
language	EN
topic	Ordos Basin Chang 7 Member oil Organic-rich shale Sedimentary characteristics Geochemical characteristics Science Q Petrology QE420-499
spellingShingle	Ordos Basin Chang 7 Member oil Organic-rich shale Sedimentary characteristics Geochemical characteristics Science Q Petrology QE420-499 Jing-Wei Cui Ru-Kai Zhu Zhong Luo Sen Li Sedimentary and geochemical characteristics of the Triassic Chang 7 Member shale in the Southeastern Ordos Basin, Central China
description	Abstract The Ordos Basin is the largest petroliferous basin in China, where the Chang 7 Member shale serves as the major source rock in the basin, with an area of more than 100,000 km2. So far, sedimentary and geochemical characterizations have rarely been conducted on the shale in shallow (< 1000 m) areas in the southeastern part of the basin, but such characterizations can help identify the genesis of organic-rich shale and promote the prediction and recovery of shale oil. In this paper, several outcrop sections of the Chang 7 Member in the Tongchuan area were observed and sampled, and sedimentary and geochemical characterizations were conducted for the well-outcropped YSC section. The study results show that the Chang 7 Member shale is widely distributed laterally with variable thickness. The organic-rich shale is 7–25 m thick in total and exhibits obvious horizontal variation in mineral composition. In the eastern sections, the shale contains organic matter of Type II2–III and is low in thermal maturity, with high clay mineral content, low K-feldspar content, and no pyrite. In the western sections, the shale contains Type II1 organic matter and is low in thermal maturity, with high clay mineral, K-feldspar, and pyrite contents. The YSC section reveals three obvious intervals in vertical mineral composition and organic abundance. The Chang 7 Member organic-rich shale (TOC > 10%) contains mainly sapropelite and liptinite, with Type II kerogen. It is generally characterized by a hydrocarbon potential of more than 70 mg/g, low maturity, and shallow–semideep lacustrine facies. In the western sections, the shale, still in a low maturity stage, has a higher hydrocarbon potential and is optional for shale oil recovery. However, the Chang 7 Member shale in the study area is highly heterogeneous and its shale oil recovery is practical only in the organic-rich intervals.
format	article
author	Jing-Wei Cui Ru-Kai Zhu Zhong Luo Sen Li
author_facet	Jing-Wei Cui Ru-Kai Zhu Zhong Luo Sen Li
author_sort	Jing-Wei Cui
title	Sedimentary and geochemical characteristics of the Triassic Chang 7 Member shale in the Southeastern Ordos Basin, Central China
title_short	Sedimentary and geochemical characteristics of the Triassic Chang 7 Member shale in the Southeastern Ordos Basin, Central China
title_full	Sedimentary and geochemical characteristics of the Triassic Chang 7 Member shale in the Southeastern Ordos Basin, Central China
title_fullStr	Sedimentary and geochemical characteristics of the Triassic Chang 7 Member shale in the Southeastern Ordos Basin, Central China
title_full_unstemmed	Sedimentary and geochemical characteristics of the Triassic Chang 7 Member shale in the Southeastern Ordos Basin, Central China
title_sort	sedimentary and geochemical characteristics of the triassic chang 7 member shale in the southeastern ordos basin, central china
publisher	KeAi Communications Co., Ltd.
publishDate	2019
url	https://doaj.org/article/c0f70321e0bd4f3190361437258614be
work_keys_str_mv	AT jingweicui sedimentaryandgeochemicalcharacteristicsofthetriassicchang7membershaleinthesoutheasternordosbasincentralchina AT rukaizhu sedimentaryandgeochemicalcharacteristicsofthetriassicchang7membershaleinthesoutheasternordosbasincentralchina AT zhongluo sedimentaryandgeochemicalcharacteristicsofthetriassicchang7membershaleinthesoutheasternordosbasincentralchina AT senli sedimentaryandgeochemicalcharacteristicsofthetriassicchang7membershaleinthesoutheasternordosbasincentralchina
_version_	1718398269170647040

Sedimentary and geochemical characteristics of the Triassic Chang 7 Member shale in the Southeastern Ordos Basin, Central China

Ejemplares similares