Improvement of Gas Compressibility Factor and Bottom-Hole Pressure Calculation Method for HTHP Reservoirs: A Field Case in Junggar Basin, China
Gas reservoirs discovered in the southern margin of the Junggar Basin generally have high temperatures (up to 172.22 °C) and high pressures (up to 171.74 MPa). If using the PVT laboratory to get the gas compressibility factor, data from the laboratory are so little that it will not satisfy the deman...
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2022-11-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/15/22/8705 |
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| author | Yun Xia Wenpeng Bai Zhipeng Xiang Wanbin Wang Qiao Guo Yang Wang Shiqing Cheng |
| author_facet | Yun Xia Wenpeng Bai Zhipeng Xiang Wanbin Wang Qiao Guo Yang Wang Shiqing Cheng |
| author_sort | Yun Xia |
| collection | DOAJ |
| description | Gas reservoirs discovered in the southern margin of the Junggar Basin generally have high temperatures (up to 172.22 °C) and high pressures (up to 171.74 MPa). If using the PVT laboratory to get the gas compressibility factor, data from the laboratory are so little that it will not satisfy the demands of reservoir engineering calculations. There are many empirical correlations for calculating the Z-factor; however, these correlations give large errors at high gas reservoir pressures. The errors in estimating the Z-factor will lead to large errors in estimating all the other gas properties such as gas formation volume factor, gas compressibility, and gas in place. In this paper, a new accurate Z-factor correlation has been developed based on PVT data by correcting the high-pressure part of the most commonly used Dranchuk-Purvis-Robinson Correlation. Multivariate nonlinear regression is used to establish the independent variable function of pseudo-critical temperatures and pressures. By comparing it with the PVT data, the DPR correlation is continuously corrected to be suitable for ultra-deep gas reservoirs with HTHP. The new correlation can be used to determine the Z-factor at any pressure range, especially for high pressures, and the error is less than 1% compared to the PVT data. Then, based on the corrected Z-factor, the Cullender-Smith method is used to calculate the bottom hole pressure in the middle of the reservoir. Finally, the Z-factor under reservoir conditions of well H2 is predicted and the Z-factor chart at different temperatures is provided. |
| first_indexed | 2024-03-09T18:21:41Z |
| format | Article |
| id | doaj.art-8d708b0922464efeb3b433c8a8462f30 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-09T18:21:41Z |
| publishDate | 2022-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-8d708b0922464efeb3b433c8a8462f302023-11-24T08:17:17ZengMDPI AGEnergies1996-10732022-11-011522870510.3390/en15228705Improvement of Gas Compressibility Factor and Bottom-Hole Pressure Calculation Method for HTHP Reservoirs: A Field Case in Junggar Basin, ChinaYun Xia0Wenpeng Bai1Zhipeng Xiang2Wanbin Wang3Qiao Guo4Yang Wang5Shiqing Cheng6Research Institute of Engineering Technology, Xinjiang Oilfield Company, PetroChina, Karamay 834000, ChinaState Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing 102249, ChinaResearch Institute of Engineering Technology, Xinjiang Oilfield Company, PetroChina, Karamay 834000, ChinaResearch Institute of Engineering Technology, Xinjiang Oilfield Company, PetroChina, Karamay 834000, ChinaState Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing 102249, ChinaState Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing 102249, ChinaState Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing 102249, ChinaGas reservoirs discovered in the southern margin of the Junggar Basin generally have high temperatures (up to 172.22 °C) and high pressures (up to 171.74 MPa). If using the PVT laboratory to get the gas compressibility factor, data from the laboratory are so little that it will not satisfy the demands of reservoir engineering calculations. There are many empirical correlations for calculating the Z-factor; however, these correlations give large errors at high gas reservoir pressures. The errors in estimating the Z-factor will lead to large errors in estimating all the other gas properties such as gas formation volume factor, gas compressibility, and gas in place. In this paper, a new accurate Z-factor correlation has been developed based on PVT data by correcting the high-pressure part of the most commonly used Dranchuk-Purvis-Robinson Correlation. Multivariate nonlinear regression is used to establish the independent variable function of pseudo-critical temperatures and pressures. By comparing it with the PVT data, the DPR correlation is continuously corrected to be suitable for ultra-deep gas reservoirs with HTHP. The new correlation can be used to determine the Z-factor at any pressure range, especially for high pressures, and the error is less than 1% compared to the PVT data. Then, based on the corrected Z-factor, the Cullender-Smith method is used to calculate the bottom hole pressure in the middle of the reservoir. Finally, the Z-factor under reservoir conditions of well H2 is predicted and the Z-factor chart at different temperatures is provided.https://www.mdpi.com/1996-1073/15/22/8705southern margin of Junggar Basinnatural gasgas compressibility factorultra-deephigh temperature and high pressurebottom-hole pressure |
| spellingShingle | Yun Xia Wenpeng Bai Zhipeng Xiang Wanbin Wang Qiao Guo Yang Wang Shiqing Cheng Improvement of Gas Compressibility Factor and Bottom-Hole Pressure Calculation Method for HTHP Reservoirs: A Field Case in Junggar Basin, China Energies southern margin of Junggar Basin natural gas gas compressibility factor ultra-deep high temperature and high pressure bottom-hole pressure |
| title | Improvement of Gas Compressibility Factor and Bottom-Hole Pressure Calculation Method for HTHP Reservoirs: A Field Case in Junggar Basin, China |
| title_full | Improvement of Gas Compressibility Factor and Bottom-Hole Pressure Calculation Method for HTHP Reservoirs: A Field Case in Junggar Basin, China |
| title_fullStr | Improvement of Gas Compressibility Factor and Bottom-Hole Pressure Calculation Method for HTHP Reservoirs: A Field Case in Junggar Basin, China |
| title_full_unstemmed | Improvement of Gas Compressibility Factor and Bottom-Hole Pressure Calculation Method for HTHP Reservoirs: A Field Case in Junggar Basin, China |
| title_short | Improvement of Gas Compressibility Factor and Bottom-Hole Pressure Calculation Method for HTHP Reservoirs: A Field Case in Junggar Basin, China |
| title_sort | improvement of gas compressibility factor and bottom hole pressure calculation method for hthp reservoirs a field case in junggar basin china |
| topic | southern margin of Junggar Basin natural gas gas compressibility factor ultra-deep high temperature and high pressure bottom-hole pressure |
| url | https://www.mdpi.com/1996-1073/15/22/8705 |
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