Experimental Investigation on Microscopic Residual Oil Distribution During CO2 Huff-and-Puff Process in Tight Oil Reservoirs
The determination of microscopic residual oil distribution is beneficial for exploiting reservoirs to their maximum potential. In order to investigate microscopic residual oil during the carbon dioxide (CO2) huff-and-puff process in tight oil reservoirs, several CO2 huff-and-puff tests with tight sa...
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MDPI AG
2018-10-01
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| Series: | Energies |
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| Online Access: | http://www.mdpi.com/1996-1073/11/10/2843 |
| _version_ | 1798041113076957184 |
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| author | Kun Qian Shenglai Yang Hongen Dou Qian Wang Lu Wang Yu Huang |
| author_facet | Kun Qian Shenglai Yang Hongen Dou Qian Wang Lu Wang Yu Huang |
| author_sort | Kun Qian |
| collection | DOAJ |
| description | The determination of microscopic residual oil distribution is beneficial for exploiting reservoirs to their maximum potential. In order to investigate microscopic residual oil during the carbon dioxide (CO2) huff-and-puff process in tight oil reservoirs, several CO2 huff-and-puff tests with tight sandstone cores were conducted at various conditions. Then, nuclear magnetic resonance (NMR) was used to determine the microscopic residual oil distribution of the cores. The experiments showed that the oil recovery factor increased from 27.22% to 52.56% when injection pressure increased from 5 MPa to 13 MPa. The oil recovery was unable to be substantially enhanced as the injection pressure further increased beyond the minimum miscible pressure. The lower limit of pore distribution where the oil was recoverable corresponded to relaxation times of 2.68 ms, 1.29 ms, and 0.74 ms at an injection pressure of 5 MPa, 11 MPa, and 16 MPa, respectively. Longer soaking time also increased the lower limit of the oil-recoverable pore distribution. However, more cycles had no obvious effect on expanding the interval of oil-recoverable pore distribution. Therefore, higher injection pressure and longer soaking time convert the residual oil in smaller and blind pores into recoverable oil. This investigation provides some technical ideas for oilfields in design development programs for optimizing the production parameters during the CO2 huff-and-puff process. |
| first_indexed | 2024-04-11T22:16:57Z |
| format | Article |
| id | doaj.art-174c320e996f499c902cef1198f5ff2d |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-04-11T22:16:57Z |
| publishDate | 2018-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-174c320e996f499c902cef1198f5ff2d2022-12-22T04:00:21ZengMDPI AGEnergies1996-10732018-10-011110284310.3390/en11102843en11102843Experimental Investigation on Microscopic Residual Oil Distribution During CO2 Huff-and-Puff Process in Tight Oil ReservoirsKun Qian0Shenglai Yang1Hongen Dou2Qian Wang3Lu Wang4Yu Huang5State Key Lab of Oil and Gas Resources and Engineering, China University of Petroleum, Beijing 102249, ChinaState Key Lab of Oil and Gas Resources and Engineering, China University of Petroleum, Beijing 102249, ChinaResearch Institute of Petroleum Exploration and Development, CNPC, Beijing 100083, ChinaState Key Lab of Oil and Gas Resources and Engineering, China University of Petroleum, Beijing 102249, ChinaState Key Lab of Oil and Gas Resources and Engineering, China University of Petroleum, Beijing 102249, ChinaState Key Lab of Oil and Gas Resources and Engineering, China University of Petroleum, Beijing 102249, ChinaThe determination of microscopic residual oil distribution is beneficial for exploiting reservoirs to their maximum potential. In order to investigate microscopic residual oil during the carbon dioxide (CO2) huff-and-puff process in tight oil reservoirs, several CO2 huff-and-puff tests with tight sandstone cores were conducted at various conditions. Then, nuclear magnetic resonance (NMR) was used to determine the microscopic residual oil distribution of the cores. The experiments showed that the oil recovery factor increased from 27.22% to 52.56% when injection pressure increased from 5 MPa to 13 MPa. The oil recovery was unable to be substantially enhanced as the injection pressure further increased beyond the minimum miscible pressure. The lower limit of pore distribution where the oil was recoverable corresponded to relaxation times of 2.68 ms, 1.29 ms, and 0.74 ms at an injection pressure of 5 MPa, 11 MPa, and 16 MPa, respectively. Longer soaking time also increased the lower limit of the oil-recoverable pore distribution. However, more cycles had no obvious effect on expanding the interval of oil-recoverable pore distribution. Therefore, higher injection pressure and longer soaking time convert the residual oil in smaller and blind pores into recoverable oil. This investigation provides some technical ideas for oilfields in design development programs for optimizing the production parameters during the CO2 huff-and-puff process.http://www.mdpi.com/1996-1073/11/10/2843tight oil reservoirenhanced oil recoveryphase behaviornuclear magnetic resonancemicroscopic residual oil distribution |
| spellingShingle | Kun Qian Shenglai Yang Hongen Dou Qian Wang Lu Wang Yu Huang Experimental Investigation on Microscopic Residual Oil Distribution During CO2 Huff-and-Puff Process in Tight Oil Reservoirs Energies tight oil reservoir enhanced oil recovery phase behavior nuclear magnetic resonance microscopic residual oil distribution |
| title | Experimental Investigation on Microscopic Residual Oil Distribution During CO2 Huff-and-Puff Process in Tight Oil Reservoirs |
| title_full | Experimental Investigation on Microscopic Residual Oil Distribution During CO2 Huff-and-Puff Process in Tight Oil Reservoirs |
| title_fullStr | Experimental Investigation on Microscopic Residual Oil Distribution During CO2 Huff-and-Puff Process in Tight Oil Reservoirs |
| title_full_unstemmed | Experimental Investigation on Microscopic Residual Oil Distribution During CO2 Huff-and-Puff Process in Tight Oil Reservoirs |
| title_short | Experimental Investigation on Microscopic Residual Oil Distribution During CO2 Huff-and-Puff Process in Tight Oil Reservoirs |
| title_sort | experimental investigation on microscopic residual oil distribution during co2 huff and puff process in tight oil reservoirs |
| topic | tight oil reservoir enhanced oil recovery phase behavior nuclear magnetic resonance microscopic residual oil distribution |
| url | http://www.mdpi.com/1996-1073/11/10/2843 |
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