Research on Stress Sensitivity of Fractured Carbonate Reservoirs Based on CT Technology
Fracture aperture change under stress has long been considered as one of primary causes of stress sensitivity of fractured gas reservoirs. However, little is known about the evolution of the morphology of fracture apertures on flow property in loading and unloading cycles. This paper reports a stres...
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| Format: | Article |
| Language: | English |
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MDPI AG
2017-11-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/10/11/1833 |
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| author | Yongfei Yang Zhihui Liu Zhixue Sun Senyou An Wenjie Zhang Pengfei Liu Jun Yao Jingsheng Ma |
| author_facet | Yongfei Yang Zhihui Liu Zhixue Sun Senyou An Wenjie Zhang Pengfei Liu Jun Yao Jingsheng Ma |
| author_sort | Yongfei Yang |
| collection | DOAJ |
| description | Fracture aperture change under stress has long been considered as one of primary causes of stress sensitivity of fractured gas reservoirs. However, little is known about the evolution of the morphology of fracture apertures on flow property in loading and unloading cycles. This paper reports a stress sensitivity experiment on carbonate core plugs in which Computed Tomography (CT) technology is applied to visualize and quantitatively evaluate morphological changes to the fracture aperture with respect to confining pressure. Fracture models were obtained at selected confining pressures on which pore-scale flow simulations were performed to estimate the equivalent absolute permeability. The results showed that with the increase of confining pressure from 0 to 0.6 MPa, the fracture aperture and equivalent permeability decreased at a greater gradient than their counterparts after 0.6 MPa. This meant that the rock sample is more stress-sensitive at low effective stress than at high effective stress. On the loading path, an exponential fitting was found to fit well between the effective confining pressure and the calculated permeability. On the unloading path, the relationship is found partially reversible, which can evidently be attributed to plastic deformation of the fracture as observed in CT images. |
| first_indexed | 2024-12-10T08:05:19Z |
| format | Article |
| id | doaj.art-42e595f583554989b315647f682fe109 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-12-10T08:05:19Z |
| publishDate | 2017-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-42e595f583554989b315647f682fe1092022-12-22T01:56:41ZengMDPI AGEnergies1996-10732017-11-011011183310.3390/en10111833en10111833Research on Stress Sensitivity of Fractured Carbonate Reservoirs Based on CT TechnologyYongfei Yang0Zhihui Liu1Zhixue Sun2Senyou An3Wenjie Zhang4Pengfei Liu5Jun Yao6Jingsheng Ma7Research Centre of Multiphase Flow in Porous Media, China University of Petroleum (East China), Qingdao 266580, ChinaResearch Centre of Multiphase Flow in Porous Media, China University of Petroleum (East China), Qingdao 266580, ChinaResearch Centre of Multiphase Flow in Porous Media, China University of Petroleum (East China), Qingdao 266580, ChinaResearch Centre of Multiphase Flow in Porous Media, China University of Petroleum (East China), Qingdao 266580, ChinaResearch Centre of Multiphase Flow in Porous Media, China University of Petroleum (East China), Qingdao 266580, ChinaResearch Centre of Multiphase Flow in Porous Media, China University of Petroleum (East China), Qingdao 266580, ChinaResearch Centre of Multiphase Flow in Porous Media, China University of Petroleum (East China), Qingdao 266580, ChinaInstitute of Petroleum Engineering, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, UKFracture aperture change under stress has long been considered as one of primary causes of stress sensitivity of fractured gas reservoirs. However, little is known about the evolution of the morphology of fracture apertures on flow property in loading and unloading cycles. This paper reports a stress sensitivity experiment on carbonate core plugs in which Computed Tomography (CT) technology is applied to visualize and quantitatively evaluate morphological changes to the fracture aperture with respect to confining pressure. Fracture models were obtained at selected confining pressures on which pore-scale flow simulations were performed to estimate the equivalent absolute permeability. The results showed that with the increase of confining pressure from 0 to 0.6 MPa, the fracture aperture and equivalent permeability decreased at a greater gradient than their counterparts after 0.6 MPa. This meant that the rock sample is more stress-sensitive at low effective stress than at high effective stress. On the loading path, an exponential fitting was found to fit well between the effective confining pressure and the calculated permeability. On the unloading path, the relationship is found partially reversible, which can evidently be attributed to plastic deformation of the fracture as observed in CT images.https://www.mdpi.com/1996-1073/10/11/1833CTdigital corefracture openingstress sensitivitypore-scale simulations |
| spellingShingle | Yongfei Yang Zhihui Liu Zhixue Sun Senyou An Wenjie Zhang Pengfei Liu Jun Yao Jingsheng Ma Research on Stress Sensitivity of Fractured Carbonate Reservoirs Based on CT Technology Energies CT digital core fracture opening stress sensitivity pore-scale simulations |
| title | Research on Stress Sensitivity of Fractured Carbonate Reservoirs Based on CT Technology |
| title_full | Research on Stress Sensitivity of Fractured Carbonate Reservoirs Based on CT Technology |
| title_fullStr | Research on Stress Sensitivity of Fractured Carbonate Reservoirs Based on CT Technology |
| title_full_unstemmed | Research on Stress Sensitivity of Fractured Carbonate Reservoirs Based on CT Technology |
| title_short | Research on Stress Sensitivity of Fractured Carbonate Reservoirs Based on CT Technology |
| title_sort | research on stress sensitivity of fractured carbonate reservoirs based on ct technology |
| topic | CT digital core fracture opening stress sensitivity pore-scale simulations |
| url | https://www.mdpi.com/1996-1073/10/11/1833 |
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