Log Evaluation of Effective Reservoir Lower Limit of Thin Oil Layer of Chang 4+5 Oil Formation in Tianciwan Area

A systematic and comprehensive evaluation of the lower limit of the effective reservoir is needed to realize the fine engraving of the thin oil reservoir in the Chang 4+5 oil formation group in the Tianciwan area of the Ordos basin. In this paper, the characteristics of tight reservoir and the lower...

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Main Authors: LI Pengbo, ZHOU Mian, GAO Luyao, ZHANG Jialei
Format: Article
Language:zho
Published: Editorial Office of Well Logging Technology 2024-04-01
Series:Cejing jishu
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Online Access:https://www.cnpcwlt.com/#/digest?ArticleID=5586
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author LI Pengbo
ZHOU Mian
GAO Luyao
ZHANG Jialei
author_facet LI Pengbo
ZHOU Mian
GAO Luyao
ZHANG Jialei
author_sort LI Pengbo
collection DOAJ
description A systematic and comprehensive evaluation of the lower limit of the effective reservoir is needed to realize the fine engraving of the thin oil reservoir in the Chang 4+5 oil formation group in the Tianciwan area of the Ordos basin. In this paper, the characteristics of tight reservoir and the lower limit standard of effective reservoir are systematically studied by using a large amount of geological, experimental, well logging and production data of Chang 4+52 oil formation in this area. The results show that the Chang 4+52 oil formation mainly develops light gray and gray white fine-grained arkose, and the grain size curve of the sandstone has two-stage characteristics. The porosity is mainly distributed in 8%~16%, and the peak interval is distributed in 10%~13%. The permeability is mainly distributed in 0.2~5.6mD, and there are two peak intervals, which are 0.3~0.4mD and 1.4~5.6mD, respectively. The average pore radius of the relatively high-permeability high-quality reservoirs with the permeability higher than 1.0mD is higher than 0.14μm, and the sorting coefficient is higher than 2.5. The lower limit of effective reservoir oil grade is oil trace grade, and the lower limit of reservoir physical property is: permeability of 0.3mD and porosity of 9.0%. The lower limits of electrical parameters of effective thickness are as follows: porosity≥9.0%; oil saturation≥40.0%; resistivity≥15Ω·m; the acoustic wave time difference is more than 225μs/m. The reservoir identification criteria for tight oil constructed in this paper by combining core, test, logging, and oil test data are reliable in thin reservoir applications.
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spelling doaj-art-e817ffc086554e93826483f771ae2b0c2025-08-20T02:33:23ZzhoEditorial Office of Well Logging TechnologyCejing jishu1004-13382024-04-0148223023910.16489/j.issn.1004-1338.2024.02.0111004-1338(2024)02-0230-10Log Evaluation of Effective Reservoir Lower Limit of Thin Oil Layer of Chang 4+5 Oil Formation in Tianciwan AreaLI Pengbo0ZHOU Mian1GAO Luyao2ZHANG Jialei3Jingbian Oil Production Plant, Yanchang Oilfield Co. LTD., Yulin, Shaanxi 718500, ChinaJingbian Oil Production Plant, Yanchang Oilfield Co. LTD., Yulin, Shaanxi 718500, ChinaJingbian Oil Production Plant, Yanchang Oilfield Co. LTD., Yulin, Shaanxi 718500, ChinaChina Railway Wuju Group Materials Industrial Co. LTD., Xi’an, Shaanxi 710061, ChinaA systematic and comprehensive evaluation of the lower limit of the effective reservoir is needed to realize the fine engraving of the thin oil reservoir in the Chang 4+5 oil formation group in the Tianciwan area of the Ordos basin. In this paper, the characteristics of tight reservoir and the lower limit standard of effective reservoir are systematically studied by using a large amount of geological, experimental, well logging and production data of Chang 4+52 oil formation in this area. The results show that the Chang 4+52 oil formation mainly develops light gray and gray white fine-grained arkose, and the grain size curve of the sandstone has two-stage characteristics. The porosity is mainly distributed in 8%~16%, and the peak interval is distributed in 10%~13%. The permeability is mainly distributed in 0.2~5.6mD, and there are two peak intervals, which are 0.3~0.4mD and 1.4~5.6mD, respectively. The average pore radius of the relatively high-permeability high-quality reservoirs with the permeability higher than 1.0mD is higher than 0.14μm, and the sorting coefficient is higher than 2.5. The lower limit of effective reservoir oil grade is oil trace grade, and the lower limit of reservoir physical property is: permeability of 0.3mD and porosity of 9.0%. The lower limits of electrical parameters of effective thickness are as follows: porosity≥9.0%; oil saturation≥40.0%; resistivity≥15Ω·m; the acoustic wave time difference is more than 225μs/m. The reservoir identification criteria for tight oil constructed in this paper by combining core, test, logging, and oil test data are reliable in thin reservoir applications.https://www.cnpcwlt.com/#/digest?ArticleID=5586log evalustiontianciwan area of ordos basinchang 4+52 oil formationlower limit of effective reservoirevaluation criteria
spellingShingle LI Pengbo
ZHOU Mian
GAO Luyao
ZHANG Jialei
Log Evaluation of Effective Reservoir Lower Limit of Thin Oil Layer of Chang 4+5 Oil Formation in Tianciwan Area
Cejing jishu
log evalustion
tianciwan area of ordos basin
chang 4+52 oil formation
lower limit of effective reservoir
evaluation criteria
title Log Evaluation of Effective Reservoir Lower Limit of Thin Oil Layer of Chang 4+5 Oil Formation in Tianciwan Area
title_full Log Evaluation of Effective Reservoir Lower Limit of Thin Oil Layer of Chang 4+5 Oil Formation in Tianciwan Area
title_fullStr Log Evaluation of Effective Reservoir Lower Limit of Thin Oil Layer of Chang 4+5 Oil Formation in Tianciwan Area
title_full_unstemmed Log Evaluation of Effective Reservoir Lower Limit of Thin Oil Layer of Chang 4+5 Oil Formation in Tianciwan Area
title_short Log Evaluation of Effective Reservoir Lower Limit of Thin Oil Layer of Chang 4+5 Oil Formation in Tianciwan Area
title_sort log evaluation of effective reservoir lower limit of thin oil layer of chang 4 5 oil formation in tianciwan area
topic log evalustion
tianciwan area of ordos basin
chang 4+52 oil formation
lower limit of effective reservoir
evaluation criteria
url https://www.cnpcwlt.com/#/digest?ArticleID=5586
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AT gaoluyao logevaluationofeffectivereservoirlowerlimitofthinoillayerofchang45oilformationintianciwanarea
AT zhangjialei logevaluationofeffectivereservoirlowerlimitofthinoillayerofchang45oilformationintianciwanarea