Mudrocks Lithofacies Characteristics and North-South Hydrocarbon Generation Difference of the Shahejie Formation in the Dongpu Sag

Lacustrine mudrocks are composed of minerals and organic matter (OM). The origin and preservation of OM are two controlling factors of the hydrocarbon generation capacity of mudrocks. It is a key method in source rock research to study the deposition process from the view of the OM and sedimentary e...

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Main Authors: Yuanfeng Li, Xiang Zeng, Jingong Cai, Xinyu Wang, Xiaoshui Mu, Yunxian Zhang
Format: Article
Language:English
Published: MDPI AG 2021-05-01
Series:Minerals
Subjects:
Online Access:https://www.mdpi.com/2075-163X/11/5/535
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spelling doaj-45a94ff9011045d39cd8fe3840a1d1472021-06-01T00:26:19ZengMDPI AGMinerals2075-163X2021-05-011153553510.3390/min11050535Mudrocks Lithofacies Characteristics and North-South Hydrocarbon Generation Difference of the Shahejie Formation in the Dongpu SagYuanfeng Li0Xiang Zeng1Jingong Cai2Xinyu Wang3Xiaoshui Mu4Yunxian Zhang5State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, ChinaState Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, ChinaState Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, ChinaCollege of Marine Geosciences, Ocean University of China, Qingdao 266100, ChinaSINOPEC Zhongyuan Oilfield Company, Puyang 457001, ChinaSINOPEC Zhongyuan Oilfield Company, Puyang 457001, ChinaLacustrine mudrocks are composed of minerals and organic matter (OM). The origin and preservation of OM are two controlling factors of the hydrocarbon generation capacity of mudrocks. It is a key method in source rock research to study the deposition process from the view of the OM and sedimentary environment. Following this idea, the reason for the discrepancy in hydrocarbon production between the northern and the southern part of Dongpu Sag is analyzed and discussed. The lacustrine mudrocks of the Shahejie Formation in Dongpu Sag are sampled and analyzed for information about mineralogy, microstructure, elemental geochemistry, and OM characteristics. The mudrocks are then divided into three lithofacies: silt-rich massive mudstone, homogeneous massive mudstone, and laminated mudstone. Each lithofacies shows distinct characteristics, and the hydrocarbon generation ability of them increases in sequence. Further discussion that the differences in hydrocarbon generation are caused by the sedimentary environment. The water depth, salinity, and reducibility of the sedimentary environments of these three lithofacies increase in sequence, as well. The correlation analysis indicates that it is the environment that controls the origin, accumulation, and preservation of OM in each lithofacies and then causes the great differences in hydrocarbon generation capacity. In Dongpu Sag, the proportion of laminated mudstone is much higher in the northern part, which leads to greater oil/gas production than the southern part. In research of source rocks, both the lithofacies characteristics and the sedimentary environments that control the characteristics should be studied.https://www.mdpi.com/2075-163X/11/5/535mudrock lithofaciesorigin and preservation of organic mattersedimentary environmenthydrocarbon generationDongpu Sag
collection DOAJ
language English
format Article
sources DOAJ
author Yuanfeng Li
Xiang Zeng
Jingong Cai
Xinyu Wang
Xiaoshui Mu
Yunxian Zhang
spellingShingle Yuanfeng Li
Xiang Zeng
Jingong Cai
Xinyu Wang
Xiaoshui Mu
Yunxian Zhang
Mudrocks Lithofacies Characteristics and North-South Hydrocarbon Generation Difference of the Shahejie Formation in the Dongpu Sag
Minerals
mudrock lithofacies
origin and preservation of organic matter
sedimentary environment
hydrocarbon generation
Dongpu Sag
author_facet Yuanfeng Li
Xiang Zeng
Jingong Cai
Xinyu Wang
Xiaoshui Mu
Yunxian Zhang
author_sort Yuanfeng Li
title Mudrocks Lithofacies Characteristics and North-South Hydrocarbon Generation Difference of the Shahejie Formation in the Dongpu Sag
title_short Mudrocks Lithofacies Characteristics and North-South Hydrocarbon Generation Difference of the Shahejie Formation in the Dongpu Sag
title_full Mudrocks Lithofacies Characteristics and North-South Hydrocarbon Generation Difference of the Shahejie Formation in the Dongpu Sag
title_fullStr Mudrocks Lithofacies Characteristics and North-South Hydrocarbon Generation Difference of the Shahejie Formation in the Dongpu Sag
title_full_unstemmed Mudrocks Lithofacies Characteristics and North-South Hydrocarbon Generation Difference of the Shahejie Formation in the Dongpu Sag
title_sort mudrocks lithofacies characteristics and north-south hydrocarbon generation difference of the shahejie formation in the dongpu sag
publisher MDPI AG
series Minerals
issn 2075-163X
publishDate 2021-05-01
description Lacustrine mudrocks are composed of minerals and organic matter (OM). The origin and preservation of OM are two controlling factors of the hydrocarbon generation capacity of mudrocks. It is a key method in source rock research to study the deposition process from the view of the OM and sedimentary environment. Following this idea, the reason for the discrepancy in hydrocarbon production between the northern and the southern part of Dongpu Sag is analyzed and discussed. The lacustrine mudrocks of the Shahejie Formation in Dongpu Sag are sampled and analyzed for information about mineralogy, microstructure, elemental geochemistry, and OM characteristics. The mudrocks are then divided into three lithofacies: silt-rich massive mudstone, homogeneous massive mudstone, and laminated mudstone. Each lithofacies shows distinct characteristics, and the hydrocarbon generation ability of them increases in sequence. Further discussion that the differences in hydrocarbon generation are caused by the sedimentary environment. The water depth, salinity, and reducibility of the sedimentary environments of these three lithofacies increase in sequence, as well. The correlation analysis indicates that it is the environment that controls the origin, accumulation, and preservation of OM in each lithofacies and then causes the great differences in hydrocarbon generation capacity. In Dongpu Sag, the proportion of laminated mudstone is much higher in the northern part, which leads to greater oil/gas production than the southern part. In research of source rocks, both the lithofacies characteristics and the sedimentary environments that control the characteristics should be studied.
topic mudrock lithofacies
origin and preservation of organic matter
sedimentary environment
hydrocarbon generation
Dongpu Sag
url https://www.mdpi.com/2075-163X/11/5/535
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