A Semi-Analytical Mathematical Model for Off-Center Fractured Vertical Wells With Asymmetrical Fractures in Columnar Coalbed Methane
Coalbed methane (CBM) is one of the important unconventional oil and gas resources. Since the permeability of the CBM reservoir is very low, CBM is usually developed by hydraulic fracturing technology to enhance gas productivity. In fact, most of the wells are not at the center of the columnar CBM r...
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| Format: | Article |
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Frontiers Media S.A.
2022-02-01
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| Series: | Frontiers in Energy Research |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fenrg.2022.829914/full |
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| author | Anzhao Ji Zhanjun Chen Yufeng Wang Guangsheng Zhang Zhenglin Mao Fenjun Chen |
| author_facet | Anzhao Ji Zhanjun Chen Yufeng Wang Guangsheng Zhang Zhenglin Mao Fenjun Chen |
| author_sort | Anzhao Ji |
| collection | DOAJ |
| description | Coalbed methane (CBM) is one of the important unconventional oil and gas resources. Since the permeability of the CBM reservoir is very low, CBM is usually developed by hydraulic fracturing technology to enhance gas productivity. In fact, most of the wells are not at the center of the columnar CBM reservoirs, which leads to different wellbore pressure responses. It is meaningful to analyze the wellbore pressure response of the off-center fractured vertical wells with asymmetrical fracture. The adsorption-desorption, fracture asymmetry are considered and a semi-analytical mathematical model is established. The pressure wellbore solution of the Laplace domain can be obtained by Laplace transformation, model coupling, and Gauss elimination. Then, the Stehfest numerical inversion is employed to obtain the pressure solution and rate distribution in the real-time domain. This semi-analytical solution is verified; the results show that the wellbore pressure includes six flow regimes, which include bilinear flow, linear flow, elliptic flow, radial flow, arc boundary reflection, and boundary dominated flow regime. The influence of fracture angle, dimensionless conductivity, and off-center distance on wellbore pressure and rate distribution are discussed in detail. |
| first_indexed | 2024-12-20T18:25:57Z |
| format | Article |
| id | doaj.art-a342a98089c14a869e05e2db122825ef |
| institution | Directory Open Access Journal |
| issn | 2296-598X |
| language | English |
| last_indexed | 2024-12-20T18:25:57Z |
| publishDate | 2022-02-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Energy Research |
| spelling | doaj.art-a342a98089c14a869e05e2db122825ef2022-12-21T19:30:10ZengFrontiers Media S.A.Frontiers in Energy Research2296-598X2022-02-011010.3389/fenrg.2022.829914829914A Semi-Analytical Mathematical Model for Off-Center Fractured Vertical Wells With Asymmetrical Fractures in Columnar Coalbed MethaneAnzhao Ji0Zhanjun Chen1Yufeng Wang2Guangsheng Zhang3Zhenglin Mao4Fenjun Chen5School of Energy Engineering, Longdong University, Qingyang, ChinaSchool of Energy Engineering, Longdong University, Qingyang, ChinaSchool of Energy Engineering, Longdong University, Qingyang, ChinaSchool of Energy Engineering, Longdong University, Qingyang, ChinaResearch Institute of Exploration Development, PetroChina Southwest Oil & Gasfield Company, Chengdu, ChinaResearch Institute of Exploration Development, PetroChina Qinghai Oil Field Company, Dunhuang, ChinaCoalbed methane (CBM) is one of the important unconventional oil and gas resources. Since the permeability of the CBM reservoir is very low, CBM is usually developed by hydraulic fracturing technology to enhance gas productivity. In fact, most of the wells are not at the center of the columnar CBM reservoirs, which leads to different wellbore pressure responses. It is meaningful to analyze the wellbore pressure response of the off-center fractured vertical wells with asymmetrical fracture. The adsorption-desorption, fracture asymmetry are considered and a semi-analytical mathematical model is established. The pressure wellbore solution of the Laplace domain can be obtained by Laplace transformation, model coupling, and Gauss elimination. Then, the Stehfest numerical inversion is employed to obtain the pressure solution and rate distribution in the real-time domain. This semi-analytical solution is verified; the results show that the wellbore pressure includes six flow regimes, which include bilinear flow, linear flow, elliptic flow, radial flow, arc boundary reflection, and boundary dominated flow regime. The influence of fracture angle, dimensionless conductivity, and off-center distance on wellbore pressure and rate distribution are discussed in detail.https://www.frontiersin.org/articles/10.3389/fenrg.2022.829914/fullhydraulically fractured wellcoalbed methaneoff-center wellasymmetrical fracturepressure transient response |
| spellingShingle | Anzhao Ji Zhanjun Chen Yufeng Wang Guangsheng Zhang Zhenglin Mao Fenjun Chen A Semi-Analytical Mathematical Model for Off-Center Fractured Vertical Wells With Asymmetrical Fractures in Columnar Coalbed Methane Frontiers in Energy Research hydraulically fractured well coalbed methane off-center well asymmetrical fracture pressure transient response |
| title | A Semi-Analytical Mathematical Model for Off-Center Fractured Vertical Wells With Asymmetrical Fractures in Columnar Coalbed Methane |
| title_full | A Semi-Analytical Mathematical Model for Off-Center Fractured Vertical Wells With Asymmetrical Fractures in Columnar Coalbed Methane |
| title_fullStr | A Semi-Analytical Mathematical Model for Off-Center Fractured Vertical Wells With Asymmetrical Fractures in Columnar Coalbed Methane |
| title_full_unstemmed | A Semi-Analytical Mathematical Model for Off-Center Fractured Vertical Wells With Asymmetrical Fractures in Columnar Coalbed Methane |
| title_short | A Semi-Analytical Mathematical Model for Off-Center Fractured Vertical Wells With Asymmetrical Fractures in Columnar Coalbed Methane |
| title_sort | semi analytical mathematical model for off center fractured vertical wells with asymmetrical fractures in columnar coalbed methane |
| topic | hydraulically fractured well coalbed methane off-center well asymmetrical fracture pressure transient response |
| url | https://www.frontiersin.org/articles/10.3389/fenrg.2022.829914/full |
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