Quantitative evaluation of tight oil reservoirs in the Chang 8 Member of the Yanchang Formation in southern Ordos Basin
The precise and quantitative characterization of reservoir properties is the key to efficient development of tight oil reservoirs. In this paper, taking the Chang 8 Member of the Yanchang Formation in the Shuimogou area in the southern Ordos Basin as an example, the sedimentary facies types, microsc...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2022-07-01
|
| Series: | Frontiers in Earth Science |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2022.963316/full |
| _version_ | 1828400408127602688 |
|---|---|
| author | Beibei Luan Bo Zhang Didong Wang Chao Deng Feng Wang |
| author_facet | Beibei Luan Bo Zhang Didong Wang Chao Deng Feng Wang |
| author_sort | Beibei Luan |
| collection | DOAJ |
| description | The precise and quantitative characterization of reservoir properties is the key to efficient development of tight oil reservoirs. In this paper, taking the Chang 8 Member of the Yanchang Formation in the Shuimogou area in the southern Ordos Basin as an example, the sedimentary facies types, microscopic pore structures, diagenesis, influencing factors of physical properties, and hydrocarbon enrichment law of tight oil reservoirs are systematically studied. The research results show that the Chang 8 Member in the study area is a typical delta front subfacies deposit, including distributary channel and inter-distributary bay microfacies. The constructive diagenesis of the Chang 8 Member include dissolution, metasomatism and rupture; while the destructive diagenesis include mechanical compaction and cementation. The Chang 8 reservoir has entered the middle diagenetic stage A. The factors affecting the physical properties of tight oil reservoirs include deposition, compaction, cementation and dissolution. The secondary pores formed by dissolution account for 10–40% of the total surface porosity, with an average value of 24%. Local structures and sediments have significant control over hydrocarbon accumulation. The westward dipping tectonic setting of the northern Shaanxi Slope provides the basic conditions for the migration of oil and gas to the eastern updip areas. The changes of lithology and physical properties in the updip direction of the structure form the blocking conditions for the continued migration of oil and gas, which is conducive to the accumulation of oil and gas. In addition, the main oil reservoirs are mainly distributed along the distributary channel of the delta front, and most of the distributary channel sandstone is more than 20 m thick. The areas of thick sand body with multiple layers in the lateral direction is the main part of oil and gas accumulation. However, the reservoirs formed on the flanks of underwater distributary channels are generally thin and poorly sorted, which is not conducive to the accumulation of hydrocarbons. |
| first_indexed | 2024-12-10T09:31:44Z |
| format | Article |
| id | doaj.art-59b74568c97c47dcaf4ed293ec76d0de |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-12-10T09:31:44Z |
| publishDate | 2022-07-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-59b74568c97c47dcaf4ed293ec76d0de2022-12-22T01:54:20ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632022-07-011010.3389/feart.2022.963316963316Quantitative evaluation of tight oil reservoirs in the Chang 8 Member of the Yanchang Formation in southern Ordos BasinBeibei Luan0Bo Zhang1Didong Wang2Chao Deng3Feng Wang4Development Department, Yanchang Oifield Co., Ltd., Yan’an, Shaanxi, ChinaZhidan Oil Production Plant, Yanchang Oilfield Co., Ltd., Zhidan, Shaanxi, ChinaDevelopment Department, Yanchang Oifield Co., Ltd., Yan’an, Shaanxi, ChinaYulin Refinery, Yanchang Petroleum (Group) Co., Ltd., Jingbian, Shaanxi, ChinaJingbian Oil Production Plant, Yanchang Oilfield Co., Ltd., Jingbian, Shaanxi, ChinaThe precise and quantitative characterization of reservoir properties is the key to efficient development of tight oil reservoirs. In this paper, taking the Chang 8 Member of the Yanchang Formation in the Shuimogou area in the southern Ordos Basin as an example, the sedimentary facies types, microscopic pore structures, diagenesis, influencing factors of physical properties, and hydrocarbon enrichment law of tight oil reservoirs are systematically studied. The research results show that the Chang 8 Member in the study area is a typical delta front subfacies deposit, including distributary channel and inter-distributary bay microfacies. The constructive diagenesis of the Chang 8 Member include dissolution, metasomatism and rupture; while the destructive diagenesis include mechanical compaction and cementation. The Chang 8 reservoir has entered the middle diagenetic stage A. The factors affecting the physical properties of tight oil reservoirs include deposition, compaction, cementation and dissolution. The secondary pores formed by dissolution account for 10–40% of the total surface porosity, with an average value of 24%. Local structures and sediments have significant control over hydrocarbon accumulation. The westward dipping tectonic setting of the northern Shaanxi Slope provides the basic conditions for the migration of oil and gas to the eastern updip areas. The changes of lithology and physical properties in the updip direction of the structure form the blocking conditions for the continued migration of oil and gas, which is conducive to the accumulation of oil and gas. In addition, the main oil reservoirs are mainly distributed along the distributary channel of the delta front, and most of the distributary channel sandstone is more than 20 m thick. The areas of thick sand body with multiple layers in the lateral direction is the main part of oil and gas accumulation. However, the reservoirs formed on the flanks of underwater distributary channels are generally thin and poorly sorted, which is not conducive to the accumulation of hydrocarbons.https://www.frontiersin.org/articles/10.3389/feart.2022.963316/fullreservoir evaluationtight oil reservoirspore typediagenesisphysical properties |
| spellingShingle | Beibei Luan Bo Zhang Didong Wang Chao Deng Feng Wang Quantitative evaluation of tight oil reservoirs in the Chang 8 Member of the Yanchang Formation in southern Ordos Basin Frontiers in Earth Science reservoir evaluation tight oil reservoirs pore type diagenesis physical properties |
| title | Quantitative evaluation of tight oil reservoirs in the Chang 8 Member of the Yanchang Formation in southern Ordos Basin |
| title_full | Quantitative evaluation of tight oil reservoirs in the Chang 8 Member of the Yanchang Formation in southern Ordos Basin |
| title_fullStr | Quantitative evaluation of tight oil reservoirs in the Chang 8 Member of the Yanchang Formation in southern Ordos Basin |
| title_full_unstemmed | Quantitative evaluation of tight oil reservoirs in the Chang 8 Member of the Yanchang Formation in southern Ordos Basin |
| title_short | Quantitative evaluation of tight oil reservoirs in the Chang 8 Member of the Yanchang Formation in southern Ordos Basin |
| title_sort | quantitative evaluation of tight oil reservoirs in the chang 8 member of the yanchang formation in southern ordos basin |
| topic | reservoir evaluation tight oil reservoirs pore type diagenesis physical properties |
| url | https://www.frontiersin.org/articles/10.3389/feart.2022.963316/full |
| work_keys_str_mv | AT beibeiluan quantitativeevaluationoftightoilreservoirsinthechang8memberoftheyanchangformationinsouthernordosbasin AT bozhang quantitativeevaluationoftightoilreservoirsinthechang8memberoftheyanchangformationinsouthernordosbasin AT didongwang quantitativeevaluationoftightoilreservoirsinthechang8memberoftheyanchangformationinsouthernordosbasin AT chaodeng quantitativeevaluationoftightoilreservoirsinthechang8memberoftheyanchangformationinsouthernordosbasin AT fengwang quantitativeevaluationoftightoilreservoirsinthechang8memberoftheyanchangformationinsouthernordosbasin |