Hydration characteristics and mechanism study of artificial fracture surface in illite rich shale gas reservoir: A case study of Longmaxi formation shale in Yongchuan District
With high clay content in shale gas reservoir, the hydration is easy during hydraulic fracturing, which will affect the fracture conductivity and productivity of gas wells. The illite content of the Longmaxi formation shale in Yongchuan District is high (more than 80% of clay mineral content), and g...
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2023-12-01
|
| Series: | Energy Reports |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2352484723003013 |
| _version_ | 1797781873905106944 |
|---|---|
| author | Xingxing Ding Qing You Jianfa Wu Jian Zhang Jiawei Liu Caili Dai Ning Sun Linan Wei Yongpeng Sun |
| author_facet | Xingxing Ding Qing You Jianfa Wu Jian Zhang Jiawei Liu Caili Dai Ning Sun Linan Wei Yongpeng Sun |
| author_sort | Xingxing Ding |
| collection | DOAJ |
| description | With high clay content in shale gas reservoir, the hydration is easy during hydraulic fracturing, which will affect the fracture conductivity and productivity of gas wells. The illite content of the Longmaxi formation shale in Yongchuan District is high (more than 80% of clay mineral content), and gas wells have a high productivity after fracturing and shut-in. However, the hydration effect mechanism of fracturing fluid on illite rich shale is not clear. Therefore, in this paper, core hydration experiments are performed for the illite rich shale reservoir. The water imbibition characteristic of near-fracture shale is obtained, and the micro-morphology and microfracture development characteristics of hydration are studied. Moreover, the hydration mechanism of near-fracture shale is then explored from the aspects of ion diffusion and mineral interlayer spacing variation. It is deduced that the fracturing fluid is spontaneously imbibed into small pores preferentially during well shut-in after fracturing. After the near-fracture shale is touched by water, some clay minerals peel and fall off from the fracture surface after hydration, accompanied by the development of microfractures. The interlayer spacing of clay minerals expands (smectite expands by 8.8% and illite 1.5%) after water immersion, and the ion diffusion occurs. The first 15 h is the rapid diffusion stage (surface effect), while the second 15 h is the stable rising stage (internal effect). This study systematically analyzes the hydration characteristics of near-fracture illite rich shale and reveals its hydration mechanism, which are crucial for the optimization of well shut-in time and exploitation system of shale gas reservoir after fracturing. |
| first_indexed | 2024-03-13T00:03:04Z |
| format | Article |
| id | doaj.art-b1bcc62fe0454e7386be6ed21a51d64f |
| institution | Directory Open Access Journal |
| issn | 2352-4847 |
| language | English |
| last_indexed | 2024-03-13T00:03:04Z |
| publishDate | 2023-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Energy Reports |
| spelling | doaj.art-b1bcc62fe0454e7386be6ed21a51d64f2023-07-13T05:29:46ZengElsevierEnergy Reports2352-48472023-12-01941744186Hydration characteristics and mechanism study of artificial fracture surface in illite rich shale gas reservoir: A case study of Longmaxi formation shale in Yongchuan DistrictXingxing Ding0Qing You1Jianfa Wu2Jian Zhang3Jiawei Liu4Caili Dai5Ning Sun6Linan Wei7Yongpeng Sun8School of Energy Resources, China University of Geosciences, Beijing 100083, ChinaSchool of Energy Resources, China University of Geosciences, Beijing 100083, China; Corresponding authors.Shale Gas Institute of Southwest Oil & Gas Field Company, PetroChina, Chengdu, Sichuan 610051, China; Shale Gas Evaluation and Exploitation Key Laboratory of Sichuan Province, Chengdu 610213, ChinaShale Gas Institute of Southwest Oil & Gas Field Company, PetroChina, Chengdu, Sichuan 610051, China; Shale Gas Evaluation and Exploitation Key Laboratory of Sichuan Province, Chengdu 610213, ChinaShale Gas Institute of Southwest Oil & Gas Field Company, PetroChina, Chengdu, Sichuan 610051, ChinaKey Laboratory of Unconventional Oil & Gas Development (China University of Petroleum (East China)), Ministry of Education, Qingdao 266580, ChinaKey Laboratory of Unconventional Oil & Gas Development (China University of Petroleum (East China)), Ministry of Education, Qingdao 266580, ChinaKey Laboratory of Unconventional Oil & Gas Development (China University of Petroleum (East China)), Ministry of Education, Qingdao 266580, ChinaKey Laboratory of Unconventional Oil & Gas Development (China University of Petroleum (East China)), Ministry of Education, Qingdao 266580, China; Corresponding authors.With high clay content in shale gas reservoir, the hydration is easy during hydraulic fracturing, which will affect the fracture conductivity and productivity of gas wells. The illite content of the Longmaxi formation shale in Yongchuan District is high (more than 80% of clay mineral content), and gas wells have a high productivity after fracturing and shut-in. However, the hydration effect mechanism of fracturing fluid on illite rich shale is not clear. Therefore, in this paper, core hydration experiments are performed for the illite rich shale reservoir. The water imbibition characteristic of near-fracture shale is obtained, and the micro-morphology and microfracture development characteristics of hydration are studied. Moreover, the hydration mechanism of near-fracture shale is then explored from the aspects of ion diffusion and mineral interlayer spacing variation. It is deduced that the fracturing fluid is spontaneously imbibed into small pores preferentially during well shut-in after fracturing. After the near-fracture shale is touched by water, some clay minerals peel and fall off from the fracture surface after hydration, accompanied by the development of microfractures. The interlayer spacing of clay minerals expands (smectite expands by 8.8% and illite 1.5%) after water immersion, and the ion diffusion occurs. The first 15 h is the rapid diffusion stage (surface effect), while the second 15 h is the stable rising stage (internal effect). This study systematically analyzes the hydration characteristics of near-fracture illite rich shale and reveals its hydration mechanism, which are crucial for the optimization of well shut-in time and exploitation system of shale gas reservoir after fracturing.http://www.sciencedirect.com/science/article/pii/S2352484723003013Shale gasClay mineralHydration characteristicsIonic diffusionInterlayer spacing expansion |
| spellingShingle | Xingxing Ding Qing You Jianfa Wu Jian Zhang Jiawei Liu Caili Dai Ning Sun Linan Wei Yongpeng Sun Hydration characteristics and mechanism study of artificial fracture surface in illite rich shale gas reservoir: A case study of Longmaxi formation shale in Yongchuan District Energy Reports Shale gas Clay mineral Hydration characteristics Ionic diffusion Interlayer spacing expansion |
| title | Hydration characteristics and mechanism study of artificial fracture surface in illite rich shale gas reservoir: A case study of Longmaxi formation shale in Yongchuan District |
| title_full | Hydration characteristics and mechanism study of artificial fracture surface in illite rich shale gas reservoir: A case study of Longmaxi formation shale in Yongchuan District |
| title_fullStr | Hydration characteristics and mechanism study of artificial fracture surface in illite rich shale gas reservoir: A case study of Longmaxi formation shale in Yongchuan District |
| title_full_unstemmed | Hydration characteristics and mechanism study of artificial fracture surface in illite rich shale gas reservoir: A case study of Longmaxi formation shale in Yongchuan District |
| title_short | Hydration characteristics and mechanism study of artificial fracture surface in illite rich shale gas reservoir: A case study of Longmaxi formation shale in Yongchuan District |
| title_sort | hydration characteristics and mechanism study of artificial fracture surface in illite rich shale gas reservoir a case study of longmaxi formation shale in yongchuan district |
| topic | Shale gas Clay mineral Hydration characteristics Ionic diffusion Interlayer spacing expansion |
| url | http://www.sciencedirect.com/science/article/pii/S2352484723003013 |
| work_keys_str_mv | AT xingxingding hydrationcharacteristicsandmechanismstudyofartificialfracturesurfaceinilliterichshalegasreservoiracasestudyoflongmaxiformationshaleinyongchuandistrict AT qingyou hydrationcharacteristicsandmechanismstudyofartificialfracturesurfaceinilliterichshalegasreservoiracasestudyoflongmaxiformationshaleinyongchuandistrict AT jianfawu hydrationcharacteristicsandmechanismstudyofartificialfracturesurfaceinilliterichshalegasreservoiracasestudyoflongmaxiformationshaleinyongchuandistrict AT jianzhang hydrationcharacteristicsandmechanismstudyofartificialfracturesurfaceinilliterichshalegasreservoiracasestudyoflongmaxiformationshaleinyongchuandistrict AT jiaweiliu hydrationcharacteristicsandmechanismstudyofartificialfracturesurfaceinilliterichshalegasreservoiracasestudyoflongmaxiformationshaleinyongchuandistrict AT cailidai hydrationcharacteristicsandmechanismstudyofartificialfracturesurfaceinilliterichshalegasreservoiracasestudyoflongmaxiformationshaleinyongchuandistrict AT ningsun hydrationcharacteristicsandmechanismstudyofartificialfracturesurfaceinilliterichshalegasreservoiracasestudyoflongmaxiformationshaleinyongchuandistrict AT linanwei hydrationcharacteristicsandmechanismstudyofartificialfracturesurfaceinilliterichshalegasreservoiracasestudyoflongmaxiformationshaleinyongchuandistrict AT yongpengsun hydrationcharacteristicsandmechanismstudyofartificialfracturesurfaceinilliterichshalegasreservoiracasestudyoflongmaxiformationshaleinyongchuandistrict |