Experimental Study on Profile Control of Polymer and Weak Gel Molecules in Porous Media
Weak gel is a gel system formed by the mixing and crosslinking of a low-concentration polymer and a slow-release crosslinker. It can be used for profile control in deep reservoir, but its effect is greatly affected by mechanical shearing. Currently, the shearing effect on weak gel is mainly studied...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-07-01
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| Series: | Gels |
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| Online Access: | https://www.mdpi.com/2310-2861/8/8/467 |
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| author | Xuanran Li Jing Wei Lun Zhao Jun Ni Libing Fu Jincai Wang |
| author_facet | Xuanran Li Jing Wei Lun Zhao Jun Ni Libing Fu Jincai Wang |
| author_sort | Xuanran Li |
| collection | DOAJ |
| description | Weak gel is a gel system formed by the mixing and crosslinking of a low-concentration polymer and a slow-release crosslinker. It can be used for profile control in deep reservoir, but its effect is greatly affected by mechanical shearing. Currently, the shearing effect on weak gel is mainly studied by way of mechanical stirring, while the effect of porous media shear on weak gel molecules and properties has been rarely discussed. In this paper, polymer solution, aluminum gel and phenolic gel were prepared. The molecular coil size, viscoelastic modulus and microscopic aggregation morphology in water solution of three systems before and after core shearing were investigated, and the injection performance of the three systems in cores with different permeabilities was tested by physical simulation experiments. The study results show that at equivalent permeability, the system with a larger equivalent sphere diameter of molecular coil is more seriously sheared and suffers greater viscosity loss. In the core with permeability of 1.0 D, polymer solution remains as the aggregation, while phenolic gel and aluminum gel cannot form network aggregations and they are inferior to polymer solution in migration capacity in the mid-deep part of the core. In the core with permeability of 1–5.8 D, the polymer solution remains as a Newtonian fluid, while phenolic gel and aluminum gel become purely viscous non-Newtonian fluids. The elastic modulus of aluminum gel and phenolic gel is four times more than that of a polymer. In the core with permeability higher than 8.5 D, aluminum gel and phenolic gel migrate with less effect by core shearing, and their profile control capacity in deep reservoir is higher than that of the polymer. In the core with permeability lower than 8.5 D, because the monomolecular activity of weak gels becomes poor, they migrate in porous media with more effect by core shearing, and their profile control and oil displacement capacity in deep reservoir is lower than that of the polymer. |
| first_indexed | 2024-03-09T09:56:47Z |
| format | Article |
| id | doaj.art-e47e7edc61bd4f86bee3d2ccb00e7e66 |
| institution | Directory Open Access Journal |
| issn | 2310-2861 |
| language | English |
| last_indexed | 2024-03-09T09:56:47Z |
| publishDate | 2022-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Gels |
| spelling | doaj.art-e47e7edc61bd4f86bee3d2ccb00e7e662023-12-01T23:43:29ZengMDPI AGGels2310-28612022-07-018846710.3390/gels8080467Experimental Study on Profile Control of Polymer and Weak Gel Molecules in Porous MediaXuanran Li0Jing Wei1Lun Zhao2Jun Ni3Libing Fu4Jincai Wang5Research Institute of Petroleum Exploration and Development (RIPED), Beijing 100083, ChinaXinjiang Keli New Technology Development Co., Ltd., Karamay 834000, ChinaResearch Institute of Petroleum Exploration and Development (RIPED), Beijing 100083, ChinaResearch Institute of Petroleum Exploration and Development (RIPED), Beijing 100083, ChinaResearch Institute of Petroleum Exploration and Development (RIPED), Beijing 100083, ChinaResearch Institute of Petroleum Exploration and Development (RIPED), Beijing 100083, ChinaWeak gel is a gel system formed by the mixing and crosslinking of a low-concentration polymer and a slow-release crosslinker. It can be used for profile control in deep reservoir, but its effect is greatly affected by mechanical shearing. Currently, the shearing effect on weak gel is mainly studied by way of mechanical stirring, while the effect of porous media shear on weak gel molecules and properties has been rarely discussed. In this paper, polymer solution, aluminum gel and phenolic gel were prepared. The molecular coil size, viscoelastic modulus and microscopic aggregation morphology in water solution of three systems before and after core shearing were investigated, and the injection performance of the three systems in cores with different permeabilities was tested by physical simulation experiments. The study results show that at equivalent permeability, the system with a larger equivalent sphere diameter of molecular coil is more seriously sheared and suffers greater viscosity loss. In the core with permeability of 1.0 D, polymer solution remains as the aggregation, while phenolic gel and aluminum gel cannot form network aggregations and they are inferior to polymer solution in migration capacity in the mid-deep part of the core. In the core with permeability of 1–5.8 D, the polymer solution remains as a Newtonian fluid, while phenolic gel and aluminum gel become purely viscous non-Newtonian fluids. The elastic modulus of aluminum gel and phenolic gel is four times more than that of a polymer. In the core with permeability higher than 8.5 D, aluminum gel and phenolic gel migrate with less effect by core shearing, and their profile control capacity in deep reservoir is higher than that of the polymer. In the core with permeability lower than 8.5 D, because the monomolecular activity of weak gels becomes poor, they migrate in porous media with more effect by core shearing, and their profile control and oil displacement capacity in deep reservoir is lower than that of the polymer.https://www.mdpi.com/2310-2861/8/8/467weak gelporous media shearmolecular coil sizeviscoelastic modulusmolecular aggregation morphology |
| spellingShingle | Xuanran Li Jing Wei Lun Zhao Jun Ni Libing Fu Jincai Wang Experimental Study on Profile Control of Polymer and Weak Gel Molecules in Porous Media Gels weak gel porous media shear molecular coil size viscoelastic modulus molecular aggregation morphology |
| title | Experimental Study on Profile Control of Polymer and Weak Gel Molecules in Porous Media |
| title_full | Experimental Study on Profile Control of Polymer and Weak Gel Molecules in Porous Media |
| title_fullStr | Experimental Study on Profile Control of Polymer and Weak Gel Molecules in Porous Media |
| title_full_unstemmed | Experimental Study on Profile Control of Polymer and Weak Gel Molecules in Porous Media |
| title_short | Experimental Study on Profile Control of Polymer and Weak Gel Molecules in Porous Media |
| title_sort | experimental study on profile control of polymer and weak gel molecules in porous media |
| topic | weak gel porous media shear molecular coil size viscoelastic modulus molecular aggregation morphology |
| url | https://www.mdpi.com/2310-2861/8/8/467 |
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