Geophysical characterization methods for sweet spots in shale oil: A case study of Niuzhuang Subsag in Shengli Oilfield

In view of the insufficient applicability of geophysical characterization methods for sweet spots in shale oil in Niuzhuang Subsag, the core and logging data were used to analyze the physical characteristics of different types of lithofacies based on basic research, and the combinatorial lithofac...

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Main Authors: ZHANG Qiang, WANG Jing, ZHOU Haiting, LÜ Shichao
Format: Article
Language:zho
Published: Editorial Office of Petroleum Geology and Recovery Efficiency 2025-07-01
Series:Youqi dizhi yu caishoulu
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Online Access:https://yqcs.publish.founderss.cn/thesisDetails#10.13673/j.pgre.202311029&lang=en
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author ZHANG Qiang
WANG Jing
ZHOU Haiting
LÜ Shichao
author_facet ZHANG Qiang
WANG Jing
ZHOU Haiting
LÜ Shichao
author_sort ZHANG Qiang
collection DOAJ
description In view of the insufficient applicability of geophysical characterization methods for sweet spots in shale oil in Niuzhuang Subsag, the core and logging data were used to analyze the physical characteristics of different types of lithofacies based on basic research, and the combinatorial lithofacies models were established for AVO forward analysis, so as to determine the elastic parameters of different lithofacies combinations. The intersection analysis was conducted using the elastic parameters obtained from prestack inversion to explore the spatial distribution of dominant lithofacies combinations. The shale oil and gas resources are rich in the terrestrial rifted lake basin in Jiyang Depression, with developed fractures and great potential for exploration and development. The favorable aspects of fractures for shale oil development are that they can effectively increase the production capacity of shale oil reservoirs, while the unfavorable aspects are that they increase the difficulty of drilling and cause frequent well kicks and lost circulation during drilling, which seriously affects the efficiency of drilling. Therefore, the accurate prediction of fractures has been a major problem in the exploration and development of shale oil in this block. In this paper, the anisotropy of the reflection coefficient of P-wave was theoretically analyzed. Based on the development characteristics and distribution pattern of shale oil fractures in the study area, OVT domain data were used to analyze the sub-azimuth stack and seismic attribute difference, and AVAZ inversion of pre-stack OVT domain seismic data was performed based on P-wave amplitude azimuthal anisotropy fracture prediction technique, so as to predict the fracture azimuth and development strength. The fracture results predicted by the pre-stack anisotropy inversion prediction were compared with actual drilling conditions and imaging logging results, and they were highly reliable, providing effective technical support for subsequent shale oil exploration and development. According to the relationship between the in-situ stress of shale oil reservoirs and the curvature attributes and elastic parameters, Young’s modulus, Poisson’s ratio, and other parameters obtained from pre-stack inversion were combined with the curvature attributes to predict the magnitude and direction of horizontal in-situ stress. Through the above research, the petrophysical and geophysical response characteristics of the sweet spots in Niuzhuang Subsag were clarified, and the geophysical characterization methods for sweet spots were established. These methods were used to comprehensively characterize the favorable target areas of shale oil.
format Article
id doaj-art-7414b6dc3afd4e58ae508c739beef0de
institution Kabale University
issn 1009-9603
language zho
publishDate 2025-07-01
publisher Editorial Office of Petroleum Geology and Recovery Efficiency
record_format Article
series Youqi dizhi yu caishoulu
spelling doaj-art-7414b6dc3afd4e58ae508c739beef0de2025-08-22T07:16:34ZzhoEditorial Office of Petroleum Geology and Recovery EfficiencyYouqi dizhi yu caishoulu1009-96032025-07-01324314510.13673/j.pgre.2023110291009-9603(2025)04-0031-15Geophysical characterization methods for sweet spots in shale oil: A case study of Niuzhuang Subsag in Shengli OilfieldZHANG Qiang0WANG Jing1ZHOU Haiting2LÜ Shichao3Exploration and Development Research Institute, Shengli Oilfield Company, SINOPEC, Dongying City, Shandong Province, 257015, ChinaExploration and Development Research Institute, Shengli Oilfield Company, SINOPEC, Dongying City, Shandong Province, 257015, ChinaExploration and Development Research Institute, Shengli Oilfield Company, SINOPEC, Dongying City, Shandong Province, 257015, ChinaExploration and Development Research Institute, Shengli Oilfield Company, SINOPEC, Dongying City, Shandong Province, 257015, ChinaIn view of the insufficient applicability of geophysical characterization methods for sweet spots in shale oil in Niuzhuang Subsag, the core and logging data were used to analyze the physical characteristics of different types of lithofacies based on basic research, and the combinatorial lithofacies models were established for AVO forward analysis, so as to determine the elastic parameters of different lithofacies combinations. The intersection analysis was conducted using the elastic parameters obtained from prestack inversion to explore the spatial distribution of dominant lithofacies combinations. The shale oil and gas resources are rich in the terrestrial rifted lake basin in Jiyang Depression, with developed fractures and great potential for exploration and development. The favorable aspects of fractures for shale oil development are that they can effectively increase the production capacity of shale oil reservoirs, while the unfavorable aspects are that they increase the difficulty of drilling and cause frequent well kicks and lost circulation during drilling, which seriously affects the efficiency of drilling. Therefore, the accurate prediction of fractures has been a major problem in the exploration and development of shale oil in this block. In this paper, the anisotropy of the reflection coefficient of P-wave was theoretically analyzed. Based on the development characteristics and distribution pattern of shale oil fractures in the study area, OVT domain data were used to analyze the sub-azimuth stack and seismic attribute difference, and AVAZ inversion of pre-stack OVT domain seismic data was performed based on P-wave amplitude azimuthal anisotropy fracture prediction technique, so as to predict the fracture azimuth and development strength. The fracture results predicted by the pre-stack anisotropy inversion prediction were compared with actual drilling conditions and imaging logging results, and they were highly reliable, providing effective technical support for subsequent shale oil exploration and development. According to the relationship between the in-situ stress of shale oil reservoirs and the curvature attributes and elastic parameters, Young’s modulus, Poisson’s ratio, and other parameters obtained from pre-stack inversion were combined with the curvature attributes to predict the magnitude and direction of horizontal in-situ stress. Through the above research, the petrophysical and geophysical response characteristics of the sweet spots in Niuzhuang Subsag were clarified, and the geophysical characterization methods for sweet spots were established. These methods were used to comprehensively characterize the favorable target areas of shale oil.https://yqcs.publish.founderss.cn/thesisDetails#10.13673/j.pgre.202311029&lang=enshale oilpetrophysicsanisotropy analysisfracture predictionin-situ stress
spellingShingle ZHANG Qiang
WANG Jing
ZHOU Haiting
LÜ Shichao
Geophysical characterization methods for sweet spots in shale oil: A case study of Niuzhuang Subsag in Shengli Oilfield
Youqi dizhi yu caishoulu
shale oil
petrophysics
anisotropy analysis
fracture prediction
in-situ stress
title Geophysical characterization methods for sweet spots in shale oil: A case study of Niuzhuang Subsag in Shengli Oilfield
title_full Geophysical characterization methods for sweet spots in shale oil: A case study of Niuzhuang Subsag in Shengli Oilfield
title_fullStr Geophysical characterization methods for sweet spots in shale oil: A case study of Niuzhuang Subsag in Shengli Oilfield
title_full_unstemmed Geophysical characterization methods for sweet spots in shale oil: A case study of Niuzhuang Subsag in Shengli Oilfield
title_short Geophysical characterization methods for sweet spots in shale oil: A case study of Niuzhuang Subsag in Shengli Oilfield
title_sort geophysical characterization methods for sweet spots in shale oil a case study of niuzhuang subsag in shengli oilfield
topic shale oil
petrophysics
anisotropy analysis
fracture prediction
in-situ stress
url https://yqcs.publish.founderss.cn/thesisDetails#10.13673/j.pgre.202311029&lang=en
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AT wangjing geophysicalcharacterizationmethodsforsweetspotsinshaleoilacasestudyofniuzhuangsubsaginshenglioilfield
AT zhouhaiting geophysicalcharacterizationmethodsforsweetspotsinshaleoilacasestudyofniuzhuangsubsaginshenglioilfield
AT lushichao geophysicalcharacterizationmethodsforsweetspotsinshaleoilacasestudyofniuzhuangsubsaginshenglioilfield