Study on the Propagation Law of CO<sub>2</sub> Displacement in Tight Conglomerate Reservoirs in the Mahu Depression, Xinjiang, China
To achieve the efficient utilization of low-permeability tight sand and gravel reservoirs with strong heterogeneity in the Mahu oil area of Xinjiang, CO<sub>2</sub> injection is used to improve oil recovery. The sweep pattern of the injected gas is closely related to the development of r...
Saved in:
| Main Authors: | , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-02-01
|
| Series: | Energies |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1996-1073/18/4/990 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849718974106828800 |
|---|---|
| author | Long Tan Jigang Zhang Jing Zhang Ruihai Jiang Jianhua Qin Yan Dong Zhenlong Deng Ping Song Chenguang Cui Wenya Zhai Fengqi Tan |
| author_facet | Long Tan Jigang Zhang Jing Zhang Ruihai Jiang Jianhua Qin Yan Dong Zhenlong Deng Ping Song Chenguang Cui Wenya Zhai Fengqi Tan |
| author_sort | Long Tan |
| collection | DOAJ |
| description | To achieve the efficient utilization of low-permeability tight sand and gravel reservoirs with strong heterogeneity in the Mahu oil area of Xinjiang, CO<sub>2</sub> injection is used to improve oil recovery. The sweep pattern of the injected gas is closely related to the development of reservoir pores and throats. Firstly, a three-dimensional model of the average pore-throat radius was established based on complete two-dimensional nuclear magnetic resonance scanning data of the target layer’s full-diameter core in the Wuerhe Formation. Subsequently, an online NMR injection CO<sub>2</sub> continuous oil displacement experiment was conducted using tight conglomerate rock cores to clarify the rules of CO<sub>2</sub> oil displacement in each pore-throat interval. Finally, the three-dimensional pore-throat model was combined with microscopic utilization patterns to quantitatively characterize the reservoir utilization rate of the CO<sub>2</sub> displacement oil and guide on-site dynamic analysis. The research results indicate that the reservoir space of the Wuerhe Formation is mainly composed of residual intergranular pores, accounting for 40.9% of the pores, followed by intragranular dissolution pores and shrinkage pores. The proportion of pore-throat coordination numbers less than 1 is relatively high, reaching 86.3%. The average pore-throat radius calculation model, established using online NMR data from the continuous coring of full-diameter cores, elucidates the characteristics of the average pore-throat radius in the Wuerhe Formation reservoir. Based on gas displacement experiments that explored the pore-throat behavior at the microscale, the calibrated CO<sub>2</sub> injection oil recovery rate was determined to be 43.9%, and the proportion of reserves utilized within the main range during CO<sub>2</sub> displacement amounted to 60.77%. The injection pressure is negatively correlated with the maximum pore-throat radius of the gas injection well group, and negatively correlated with the proportion of the 0.9~2 μm distribution of large pore throats in each gas injection well group. |
| format | Article |
| id | doaj-art-980d763753a347bb905d7b9b3189bcc9 |
| institution | DOAJ |
| issn | 1996-1073 |
| language | English |
| publishDate | 2025-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj-art-980d763753a347bb905d7b9b3189bcc92025-08-20T03:12:14ZengMDPI AGEnergies1996-10732025-02-0118499010.3390/en18040990Study on the Propagation Law of CO<sub>2</sub> Displacement in Tight Conglomerate Reservoirs in the Mahu Depression, Xinjiang, ChinaLong Tan0Jigang Zhang1Jing Zhang2Ruihai Jiang3Jianhua Qin4Yan Dong5Zhenlong Deng6Ping Song7Chenguang Cui8Wenya Zhai9Fengqi Tan10Research Institute of Exploration and Development, PetroChina Xinjiang Oilfield Company, Karamay 834000, ChinaResearch Institute of Exploration and Development, PetroChina Xinjiang Oilfield Company, Karamay 834000, ChinaResearch Institute of Exploration and Development, PetroChina Xinjiang Oilfield Company, Karamay 834000, ChinaCollege of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, ChinaResearch Institute of Exploration and Development, PetroChina Xinjiang Oilfield Company, Karamay 834000, ChinaResearch Institute of Exploration and Development, PetroChina Xinjiang Oilfield Company, Karamay 834000, ChinaResearch Institute of Exploration and Development, PetroChina Xinjiang Oilfield Company, Karamay 834000, ChinaResearch Institute of Exploration and Development, PetroChina Xinjiang Oilfield Company, Karamay 834000, ChinaResearch Institute of Exploration and Development, PetroChina Xinjiang Oilfield Company, Karamay 834000, ChinaResearch Institute of Exploration and Development, PetroChina Xinjiang Oilfield Company, Karamay 834000, ChinaCollege of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, ChinaTo achieve the efficient utilization of low-permeability tight sand and gravel reservoirs with strong heterogeneity in the Mahu oil area of Xinjiang, CO<sub>2</sub> injection is used to improve oil recovery. The sweep pattern of the injected gas is closely related to the development of reservoir pores and throats. Firstly, a three-dimensional model of the average pore-throat radius was established based on complete two-dimensional nuclear magnetic resonance scanning data of the target layer’s full-diameter core in the Wuerhe Formation. Subsequently, an online NMR injection CO<sub>2</sub> continuous oil displacement experiment was conducted using tight conglomerate rock cores to clarify the rules of CO<sub>2</sub> oil displacement in each pore-throat interval. Finally, the three-dimensional pore-throat model was combined with microscopic utilization patterns to quantitatively characterize the reservoir utilization rate of the CO<sub>2</sub> displacement oil and guide on-site dynamic analysis. The research results indicate that the reservoir space of the Wuerhe Formation is mainly composed of residual intergranular pores, accounting for 40.9% of the pores, followed by intragranular dissolution pores and shrinkage pores. The proportion of pore-throat coordination numbers less than 1 is relatively high, reaching 86.3%. The average pore-throat radius calculation model, established using online NMR data from the continuous coring of full-diameter cores, elucidates the characteristics of the average pore-throat radius in the Wuerhe Formation reservoir. Based on gas displacement experiments that explored the pore-throat behavior at the microscale, the calibrated CO<sub>2</sub> injection oil recovery rate was determined to be 43.9%, and the proportion of reserves utilized within the main range during CO<sub>2</sub> displacement amounted to 60.77%. The injection pressure is negatively correlated with the maximum pore-throat radius of the gas injection well group, and negatively correlated with the proportion of the 0.9~2 μm distribution of large pore throats in each gas injection well group.https://www.mdpi.com/1996-1073/18/4/990Mahu DepressionCO<sub>2</sub> displacementfull-diameter coreonline magnetic resonance scanningaverage pore-throat radius |
| spellingShingle | Long Tan Jigang Zhang Jing Zhang Ruihai Jiang Jianhua Qin Yan Dong Zhenlong Deng Ping Song Chenguang Cui Wenya Zhai Fengqi Tan Study on the Propagation Law of CO<sub>2</sub> Displacement in Tight Conglomerate Reservoirs in the Mahu Depression, Xinjiang, China Energies Mahu Depression CO<sub>2</sub> displacement full-diameter core online magnetic resonance scanning average pore-throat radius |
| title | Study on the Propagation Law of CO<sub>2</sub> Displacement in Tight Conglomerate Reservoirs in the Mahu Depression, Xinjiang, China |
| title_full | Study on the Propagation Law of CO<sub>2</sub> Displacement in Tight Conglomerate Reservoirs in the Mahu Depression, Xinjiang, China |
| title_fullStr | Study on the Propagation Law of CO<sub>2</sub> Displacement in Tight Conglomerate Reservoirs in the Mahu Depression, Xinjiang, China |
| title_full_unstemmed | Study on the Propagation Law of CO<sub>2</sub> Displacement in Tight Conglomerate Reservoirs in the Mahu Depression, Xinjiang, China |
| title_short | Study on the Propagation Law of CO<sub>2</sub> Displacement in Tight Conglomerate Reservoirs in the Mahu Depression, Xinjiang, China |
| title_sort | study on the propagation law of co sub 2 sub displacement in tight conglomerate reservoirs in the mahu depression xinjiang china |
| topic | Mahu Depression CO<sub>2</sub> displacement full-diameter core online magnetic resonance scanning average pore-throat radius |
| url | https://www.mdpi.com/1996-1073/18/4/990 |
| work_keys_str_mv | AT longtan studyonthepropagationlawofcosub2subdisplacementintightconglomeratereservoirsinthemahudepressionxinjiangchina AT jigangzhang studyonthepropagationlawofcosub2subdisplacementintightconglomeratereservoirsinthemahudepressionxinjiangchina AT jingzhang studyonthepropagationlawofcosub2subdisplacementintightconglomeratereservoirsinthemahudepressionxinjiangchina AT ruihaijiang studyonthepropagationlawofcosub2subdisplacementintightconglomeratereservoirsinthemahudepressionxinjiangchina AT jianhuaqin studyonthepropagationlawofcosub2subdisplacementintightconglomeratereservoirsinthemahudepressionxinjiangchina AT yandong studyonthepropagationlawofcosub2subdisplacementintightconglomeratereservoirsinthemahudepressionxinjiangchina AT zhenlongdeng studyonthepropagationlawofcosub2subdisplacementintightconglomeratereservoirsinthemahudepressionxinjiangchina AT pingsong studyonthepropagationlawofcosub2subdisplacementintightconglomeratereservoirsinthemahudepressionxinjiangchina AT chenguangcui studyonthepropagationlawofcosub2subdisplacementintightconglomeratereservoirsinthemahudepressionxinjiangchina AT wenyazhai studyonthepropagationlawofcosub2subdisplacementintightconglomeratereservoirsinthemahudepressionxinjiangchina AT fengqitan studyonthepropagationlawofcosub2subdisplacementintightconglomeratereservoirsinthemahudepressionxinjiangchina |