Phase Behavior Identification and Formation Mechanisms of the BZ19-6 Condensate Gas Reservoir in the Deep Bozhong Sag, Bohai Bay Basin, Eastern China
Significant developments have been observed in recent years, in the field of deep part exploration in the Bozhong Sag, Bohai Bay Basin in eastern China. The BZ19-6 large condensate gas field, the largest gas field in the Bohai Bay Basin, was discovered for the first time in a typical oil-type basin....
Saved in:
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2021-01-01
|
| Series: | Geofluids |
| Online Access: | http://dx.doi.org/10.1155/2021/6622795 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832561357040386048 |
|---|---|
| author | Zhenliang Wang Shengdong Xiao Feilong Wang Guomin Tang Liwen Zhu Zilong Zhao |
| author_facet | Zhenliang Wang Shengdong Xiao Feilong Wang Guomin Tang Liwen Zhu Zilong Zhao |
| author_sort | Zhenliang Wang |
| collection | DOAJ |
| description | Significant developments have been observed in recent years, in the field of deep part exploration in the Bozhong Sag, Bohai Bay Basin in eastern China. The BZ19-6 large condensate gas field, the largest gas field in the Bohai Bay Basin, was discovered for the first time in a typical oil-type basin. The proven oil and gas geological reserves in the deeply buried hills of the Archean metamorphic rocks, amount to approximately 3×108 tons of oil equivalent. However, the phase behavior and genetic mechanisms of hydrocarbon fluids are still unclear. In this study, the phase diagram identification method and various empirical statistical methods, such as the block diagram method, φ1 parameter method, rank number method, and Z-factor method were implemented to comprehensively identify the phase behavior types of the BZ19-6 condensate gas reservoir. The genetic mechanism of the BZ19-6 condensate gas reservoir was investigated in detail through analyses of physical properties of the fluid at high temperatures and pressures, organic geochemical characteristics of condensate oil and gas, and regional tectonic background. Consequently, this study is shown as follows: (1) The BZ19-6 condensate gas reservoir is a part of a secondary condensate gas reservoir with oil rings, formed synthetically since the Neogene period due to multiple factors, such as retrograde evaporation from deep burial and high temperature, inorganic CO2 charging from the deep mantle, and late natural gas invasion. (2) The hydrocarbon accumulation process of the BZ19-6 condensate gas reservoir is as follows: First, a large amount of oil is accumulated at the end of the lower Minghuazhen deposition (5 Ma BP); second, a large amount of natural gas is generated in the deep-source kitchen and mantle-derived inorganic CO2 charged into the early formed oil reservoirs at the end of the upper Minghuazhen deposition (2 Ma BP). As a result, the content of gaseous hydrocarbons in the hydrocarbon system of the reservoir increased, which led to large amounts of liquid hydrocarbons dissolved in gaseous hydrocarbons and significantly reduced the critical temperature of the hydrocarbon system. Therefore, existing secondary condensate gas reservoirs are formed when the critical temperature is lower than the formation temperature and it enters the critical condensate temperature range. |
| format | Article |
| id | doaj-art-5b2f601125e3408fbaabc4ee77fe965a |
| institution | Kabale University |
| issn | 1468-8115 1468-8123 |
| language | English |
| publishDate | 2021-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geofluids |
| spelling | doaj-art-5b2f601125e3408fbaabc4ee77fe965a2025-02-03T01:25:11ZengWileyGeofluids1468-81151468-81232021-01-01202110.1155/2021/66227956622795Phase Behavior Identification and Formation Mechanisms of the BZ19-6 Condensate Gas Reservoir in the Deep Bozhong Sag, Bohai Bay Basin, Eastern ChinaZhenliang Wang0Shengdong Xiao1Feilong Wang2Guomin Tang3Liwen Zhu4Zilong Zhao5State Key Laboratory of Continental Dynamics (Northwest University), Xi’an, Shaanxi 710069, ChinaState Key Laboratory of Continental Dynamics (Northwest University), Xi’an, Shaanxi 710069, ChinaTianjin Branch of China National Offshore Oil Limited Corporation, Tianjin 300452, ChinaTianjin Branch of China National Offshore Oil Limited Corporation, Tianjin 300452, ChinaState Key Laboratory of Continental Dynamics (Northwest University), Xi’an, Shaanxi 710069, ChinaState Key Laboratory of Continental Dynamics (Northwest University), Xi’an, Shaanxi 710069, ChinaSignificant developments have been observed in recent years, in the field of deep part exploration in the Bozhong Sag, Bohai Bay Basin in eastern China. The BZ19-6 large condensate gas field, the largest gas field in the Bohai Bay Basin, was discovered for the first time in a typical oil-type basin. The proven oil and gas geological reserves in the deeply buried hills of the Archean metamorphic rocks, amount to approximately 3×108 tons of oil equivalent. However, the phase behavior and genetic mechanisms of hydrocarbon fluids are still unclear. In this study, the phase diagram identification method and various empirical statistical methods, such as the block diagram method, φ1 parameter method, rank number method, and Z-factor method were implemented to comprehensively identify the phase behavior types of the BZ19-6 condensate gas reservoir. The genetic mechanism of the BZ19-6 condensate gas reservoir was investigated in detail through analyses of physical properties of the fluid at high temperatures and pressures, organic geochemical characteristics of condensate oil and gas, and regional tectonic background. Consequently, this study is shown as follows: (1) The BZ19-6 condensate gas reservoir is a part of a secondary condensate gas reservoir with oil rings, formed synthetically since the Neogene period due to multiple factors, such as retrograde evaporation from deep burial and high temperature, inorganic CO2 charging from the deep mantle, and late natural gas invasion. (2) The hydrocarbon accumulation process of the BZ19-6 condensate gas reservoir is as follows: First, a large amount of oil is accumulated at the end of the lower Minghuazhen deposition (5 Ma BP); second, a large amount of natural gas is generated in the deep-source kitchen and mantle-derived inorganic CO2 charged into the early formed oil reservoirs at the end of the upper Minghuazhen deposition (2 Ma BP). As a result, the content of gaseous hydrocarbons in the hydrocarbon system of the reservoir increased, which led to large amounts of liquid hydrocarbons dissolved in gaseous hydrocarbons and significantly reduced the critical temperature of the hydrocarbon system. Therefore, existing secondary condensate gas reservoirs are formed when the critical temperature is lower than the formation temperature and it enters the critical condensate temperature range.http://dx.doi.org/10.1155/2021/6622795 |
| spellingShingle | Zhenliang Wang Shengdong Xiao Feilong Wang Guomin Tang Liwen Zhu Zilong Zhao Phase Behavior Identification and Formation Mechanisms of the BZ19-6 Condensate Gas Reservoir in the Deep Bozhong Sag, Bohai Bay Basin, Eastern China Geofluids |
| title | Phase Behavior Identification and Formation Mechanisms of the BZ19-6 Condensate Gas Reservoir in the Deep Bozhong Sag, Bohai Bay Basin, Eastern China |
| title_full | Phase Behavior Identification and Formation Mechanisms of the BZ19-6 Condensate Gas Reservoir in the Deep Bozhong Sag, Bohai Bay Basin, Eastern China |
| title_fullStr | Phase Behavior Identification and Formation Mechanisms of the BZ19-6 Condensate Gas Reservoir in the Deep Bozhong Sag, Bohai Bay Basin, Eastern China |
| title_full_unstemmed | Phase Behavior Identification and Formation Mechanisms of the BZ19-6 Condensate Gas Reservoir in the Deep Bozhong Sag, Bohai Bay Basin, Eastern China |
| title_short | Phase Behavior Identification and Formation Mechanisms of the BZ19-6 Condensate Gas Reservoir in the Deep Bozhong Sag, Bohai Bay Basin, Eastern China |
| title_sort | phase behavior identification and formation mechanisms of the bz19 6 condensate gas reservoir in the deep bozhong sag bohai bay basin eastern china |
| url | http://dx.doi.org/10.1155/2021/6622795 |
| work_keys_str_mv | AT zhenliangwang phasebehavioridentificationandformationmechanismsofthebz196condensategasreservoirinthedeepbozhongsagbohaibaybasineasternchina AT shengdongxiao phasebehavioridentificationandformationmechanismsofthebz196condensategasreservoirinthedeepbozhongsagbohaibaybasineasternchina AT feilongwang phasebehavioridentificationandformationmechanismsofthebz196condensategasreservoirinthedeepbozhongsagbohaibaybasineasternchina AT guomintang phasebehavioridentificationandformationmechanismsofthebz196condensategasreservoirinthedeepbozhongsagbohaibaybasineasternchina AT liwenzhu phasebehavioridentificationandformationmechanismsofthebz196condensategasreservoirinthedeepbozhongsagbohaibaybasineasternchina AT zilongzhao phasebehavioridentificationandformationmechanismsofthebz196condensategasreservoirinthedeepbozhongsagbohaibaybasineasternchina |