Families of reservoired crude oils from the Cangdong Sag, Bohai Bay Basin, China

Xiong Cheng, Zhichao Mao, Rong Mao, Zhiquan Li, Quansheng Guan, Xi Chen

Research output: Contribution to journalArticleResearchpeer-review

Abstract

The organic geochemistry of 35 crude oils from six oil fields across the Cangdong Sag, Bohai Bay Basin, was characterized and an oil family classification was carried out for the first time. Four oil families were classified based on 18 parameters related to source and depositional environment using hierarchical cluster analysis. The families have broadly similar geochemical characteristics which suggest oils derived from lacustrine source rocks deposited in a reducing environment. Family A has relatively abundant C27 steranes and C30 4α-methyl-24-ethylcholestanes, high Pr/Ph, C22/C21 tricyclic terpane and C31R/C30 hopane ratios, and low ETR, C26/C25 tricyclic terpane and C35S/C34S homohopane ratios. Family A shows higher thermal maturity than families C and D, but lower than family B. The most distinct feature for Family B is the high gammacerane index; they also show slightly higher C22/C21 tricyclic terpane, C31R/C30 hopane and C29/C30 hopane, lower dibenzothiophene/phenanthrene, and higher maturity than the other families. Families C and D oils are low maturity and they are more similar to each other than families A and B based on most biomarker ratios. However, family C can be distinguished from family D by slightly higher C27/C29 steranes and C30 4Me/C29 steranes C30 4α-methyl-24-ethylcholestanes/C29 steranes, and lower C29 steranes/C30 hopane ratios. A preliminary oil–source rock correlation suggests that the oil families originated from various intervals having different organofacies within the second member of the Kongdian Formation. Family A is more widespread than the other families, supporting extensive distribution of the source rock. Family B was only found in the southern part of Kongdong slope, which suggests limited geographical distribution of the related source rock. Families C and D show similar geographical distributions and dominate Wangguantun, Shenjiapu and Shenvsi fields, suggesting that the source kitchens are near these regions.

LanguageEnglish
Pages115-125
Number of pages11
JournalOrganic Geochemistry
Volume122
DOIs
Publication statusPublished - Aug 2018

Fingerprint

Petroleum
crude oil
Oils
Rocks
basin
Geographical distribution
Kitchens
source rock
Geochemistry
oil
Cluster analysis
Biomarkers
Oil fields
family
geographical distribution
hopane
organic geochemistry
thermal maturity
phenanthrene

Keywords

  • Crude oil
  • Biomarker
  • Source input
  • Depositional environment
  • Maturity
  • Oil-to-oil correlation

Cite this

Cheng, Xiong ; Mao, Zhichao ; Mao, Rong ; Li, Zhiquan ; Guan, Quansheng ; Chen, Xi. / Families of reservoired crude oils from the Cangdong Sag, Bohai Bay Basin, China. In: Organic Geochemistry. 2018 ; Vol. 122. pp. 115-125.
@article{969225feb8224f38b83314b2baab1dbc,
title = "Families of reservoired crude oils from the Cangdong Sag, Bohai Bay Basin, China",
abstract = "The organic geochemistry of 35 crude oils from six oil fields across the Cangdong Sag, Bohai Bay Basin, was characterized and an oil family classification was carried out for the first time. Four oil families were classified based on 18 parameters related to source and depositional environment using hierarchical cluster analysis. The families have broadly similar geochemical characteristics which suggest oils derived from lacustrine source rocks deposited in a reducing environment. Family A has relatively abundant C27 steranes and C30 4α-methyl-24-ethylcholestanes, high Pr/Ph, C22/C21 tricyclic terpane and C31R/C30 hopane ratios, and low ETR, C26/C25 tricyclic terpane and C35S/C34S homohopane ratios. Family A shows higher thermal maturity than families C and D, but lower than family B. The most distinct feature for Family B is the high gammacerane index; they also show slightly higher C22/C21 tricyclic terpane, C31R/C30 hopane and C29/C30 hopane, lower dibenzothiophene/phenanthrene, and higher maturity than the other families. Families C and D oils are low maturity and they are more similar to each other than families A and B based on most biomarker ratios. However, family C can be distinguished from family D by slightly higher C27/C29 steranes and C30 4Me/C29 steranes C30 4α-methyl-24-ethylcholestanes/C29 steranes, and lower C29 steranes/C30 hopane ratios. A preliminary oil–source rock correlation suggests that the oil families originated from various intervals having different organofacies within the second member of the Kongdian Formation. Family A is more widespread than the other families, supporting extensive distribution of the source rock. Family B was only found in the southern part of Kongdong slope, which suggests limited geographical distribution of the related source rock. Families C and D show similar geographical distributions and dominate Wangguantun, Shenjiapu and Shenvsi fields, suggesting that the source kitchens are near these regions.",
keywords = "Crude oil, Biomarker, Source input, Depositional environment, Maturity, Oil-to-oil correlation",
author = "Xiong Cheng and Zhichao Mao and Rong Mao and Zhiquan Li and Quansheng Guan and Xi Chen",
year = "2018",
month = "8",
doi = "10.1016/j.orggeochem.2018.05.008",
language = "English",
volume = "122",
pages = "115--125",
journal = "Organic Geochemistry",
issn = "0146-6380",
publisher = "Elsevier",

}

Families of reservoired crude oils from the Cangdong Sag, Bohai Bay Basin, China. / Cheng, Xiong; Mao, Zhichao; Mao, Rong; Li, Zhiquan; Guan, Quansheng; Chen, Xi.

In: Organic Geochemistry, Vol. 122, 08.2018, p. 115-125.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Families of reservoired crude oils from the Cangdong Sag, Bohai Bay Basin, China

AU - Cheng, Xiong

AU - Mao, Zhichao

AU - Mao, Rong

AU - Li, Zhiquan

AU - Guan, Quansheng

AU - Chen, Xi

PY - 2018/8

Y1 - 2018/8

N2 - The organic geochemistry of 35 crude oils from six oil fields across the Cangdong Sag, Bohai Bay Basin, was characterized and an oil family classification was carried out for the first time. Four oil families were classified based on 18 parameters related to source and depositional environment using hierarchical cluster analysis. The families have broadly similar geochemical characteristics which suggest oils derived from lacustrine source rocks deposited in a reducing environment. Family A has relatively abundant C27 steranes and C30 4α-methyl-24-ethylcholestanes, high Pr/Ph, C22/C21 tricyclic terpane and C31R/C30 hopane ratios, and low ETR, C26/C25 tricyclic terpane and C35S/C34S homohopane ratios. Family A shows higher thermal maturity than families C and D, but lower than family B. The most distinct feature for Family B is the high gammacerane index; they also show slightly higher C22/C21 tricyclic terpane, C31R/C30 hopane and C29/C30 hopane, lower dibenzothiophene/phenanthrene, and higher maturity than the other families. Families C and D oils are low maturity and they are more similar to each other than families A and B based on most biomarker ratios. However, family C can be distinguished from family D by slightly higher C27/C29 steranes and C30 4Me/C29 steranes C30 4α-methyl-24-ethylcholestanes/C29 steranes, and lower C29 steranes/C30 hopane ratios. A preliminary oil–source rock correlation suggests that the oil families originated from various intervals having different organofacies within the second member of the Kongdian Formation. Family A is more widespread than the other families, supporting extensive distribution of the source rock. Family B was only found in the southern part of Kongdong slope, which suggests limited geographical distribution of the related source rock. Families C and D show similar geographical distributions and dominate Wangguantun, Shenjiapu and Shenvsi fields, suggesting that the source kitchens are near these regions.

AB - The organic geochemistry of 35 crude oils from six oil fields across the Cangdong Sag, Bohai Bay Basin, was characterized and an oil family classification was carried out for the first time. Four oil families were classified based on 18 parameters related to source and depositional environment using hierarchical cluster analysis. The families have broadly similar geochemical characteristics which suggest oils derived from lacustrine source rocks deposited in a reducing environment. Family A has relatively abundant C27 steranes and C30 4α-methyl-24-ethylcholestanes, high Pr/Ph, C22/C21 tricyclic terpane and C31R/C30 hopane ratios, and low ETR, C26/C25 tricyclic terpane and C35S/C34S homohopane ratios. Family A shows higher thermal maturity than families C and D, but lower than family B. The most distinct feature for Family B is the high gammacerane index; they also show slightly higher C22/C21 tricyclic terpane, C31R/C30 hopane and C29/C30 hopane, lower dibenzothiophene/phenanthrene, and higher maturity than the other families. Families C and D oils are low maturity and they are more similar to each other than families A and B based on most biomarker ratios. However, family C can be distinguished from family D by slightly higher C27/C29 steranes and C30 4Me/C29 steranes C30 4α-methyl-24-ethylcholestanes/C29 steranes, and lower C29 steranes/C30 hopane ratios. A preliminary oil–source rock correlation suggests that the oil families originated from various intervals having different organofacies within the second member of the Kongdian Formation. Family A is more widespread than the other families, supporting extensive distribution of the source rock. Family B was only found in the southern part of Kongdong slope, which suggests limited geographical distribution of the related source rock. Families C and D show similar geographical distributions and dominate Wangguantun, Shenjiapu and Shenvsi fields, suggesting that the source kitchens are near these regions.

KW - Crude oil

KW - Biomarker

KW - Source input

KW - Depositional environment

KW - Maturity

KW - Oil-to-oil correlation

UR - http://www.scopus.com/inward/record.url?scp=85047823539&partnerID=8YFLogxK

U2 - 10.1016/j.orggeochem.2018.05.008

DO - 10.1016/j.orggeochem.2018.05.008

M3 - Article

VL - 122

SP - 115

EP - 125

JO - Organic Geochemistry

T2 - Organic Geochemistry

JF - Organic Geochemistry

SN - 0146-6380

ER -