Performance evaluation of microemulsion acid for integrated acid fracturing in Middle Eastern carbonate reservoirs
Considering the characteristics of carbonate reservoirs in the Middle East, a low-viscosity microemulsion acid that can be prepared on site and has an appropriate retardation ability was developed. It was compared with four conventional acid systems (hydrochloric acid, gelled acid, emulsified acid a...
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| Format: | Article |
| Language: | English |
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KeAi Communications Co., Ltd.
2023-10-01
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| Series: | Petroleum Exploration and Development |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S1876380423604586 |
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| author | Yunjin WANG Fujian ZHOU Hang SU Yuan LI Fuwei YU Rencheng DONG Qing WANG Junjian LI |
| author_facet | Yunjin WANG Fujian ZHOU Hang SU Yuan LI Fuwei YU Rencheng DONG Qing WANG Junjian LI |
| author_sort | Yunjin WANG |
| collection | DOAJ |
| description | Considering the characteristics of carbonate reservoirs in the Middle East, a low-viscosity microemulsion acid that can be prepared on site and has an appropriate retardation ability was developed. It was compared with four conventional acid systems (hydrochloric acid, gelled acid, emulsified acid and surfactant acid) through experiments of rotating disk, multistage acid fracturing and core flooding with CT scanning. The micro-etching characteristics and conductivity of fracture surfaces were clarified, and the variation of saturation field during water invasion and flowback of spent acid and the recovery of oil phase relative permeability were quantitatively evaluated. The study shows that the addition of negatively charged agent to the oil core of microemulsion acid can enhance its adsorption capacity on the limestone surface and significantly reduce the H+ mass transfer rate. Moreover, the negatively charged oil core is immiscible with the Ca2 + salt, so that the microemulsion acid can keep an overall structure not be damaged by Ca2 + salt generated during reaction, with adjustable adsorption capacity and stable microemulsion structure. With high vertical permeability along the fracture walls, the microemulsion acid can penetrate into deep fracture wall to form network etching, which helps greatly improve the permeability of reservoirs around the fractures and keep a high conductivity under a high closure pressure. The spent microemulsion acid is miscible with crude oil to form microemulsion. The microemulsion, oil and water are in a nearly miscible state, with basically no water block and low flowback resistance, the flowback of spent acid and the relative permeability of oil are recovered to a high degree. |
| first_indexed | 2024-03-11T16:52:01Z |
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| id | doaj.art-0352e33f408040e39e978904fb98025e |
| institution | Directory Open Access Journal |
| issn | 1876-3804 |
| language | English |
| last_indexed | 2024-03-11T16:52:01Z |
| publishDate | 2023-10-01 |
| publisher | KeAi Communications Co., Ltd. |
| record_format | Article |
| series | Petroleum Exploration and Development |
| spelling | doaj.art-0352e33f408040e39e978904fb98025e2023-10-21T04:22:26ZengKeAi Communications Co., Ltd.Petroleum Exploration and Development1876-38042023-10-0150511961205Performance evaluation of microemulsion acid for integrated acid fracturing in Middle Eastern carbonate reservoirsYunjin WANG0Fujian ZHOU1Hang SU2Yuan LI3Fuwei YU4Rencheng DONG5Qing WANG6Junjian LI7State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, China; MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing 102249, ChinaState Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, China; MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing 102249, China; Corresponding authorChina National Oil and Gas Exploration and Development Corporation, Beijing 100034, ChinaPetroChina Research Institute of Petroleum Exploration & Development, Beijing 100083, ChinaPetroChina Research Institute of Petroleum Exploration & Development, Beijing 100083, ChinaUniversity of Texas at Austin, Austin TX78712, USAState Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, China; MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing 102249, ChinaState Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, China; MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing 102249, ChinaConsidering the characteristics of carbonate reservoirs in the Middle East, a low-viscosity microemulsion acid that can be prepared on site and has an appropriate retardation ability was developed. It was compared with four conventional acid systems (hydrochloric acid, gelled acid, emulsified acid and surfactant acid) through experiments of rotating disk, multistage acid fracturing and core flooding with CT scanning. The micro-etching characteristics and conductivity of fracture surfaces were clarified, and the variation of saturation field during water invasion and flowback of spent acid and the recovery of oil phase relative permeability were quantitatively evaluated. The study shows that the addition of negatively charged agent to the oil core of microemulsion acid can enhance its adsorption capacity on the limestone surface and significantly reduce the H+ mass transfer rate. Moreover, the negatively charged oil core is immiscible with the Ca2 + salt, so that the microemulsion acid can keep an overall structure not be damaged by Ca2 + salt generated during reaction, with adjustable adsorption capacity and stable microemulsion structure. With high vertical permeability along the fracture walls, the microemulsion acid can penetrate into deep fracture wall to form network etching, which helps greatly improve the permeability of reservoirs around the fractures and keep a high conductivity under a high closure pressure. The spent microemulsion acid is miscible with crude oil to form microemulsion. The microemulsion, oil and water are in a nearly miscible state, with basically no water block and low flowback resistance, the flowback of spent acid and the relative permeability of oil are recovered to a high degree.http://www.sciencedirect.com/science/article/pii/S1876380423604586Middle East carbonatemicroemulsion acidacid-rock reactionconductivityspent acid flowbackpermeability recovery |
| spellingShingle | Yunjin WANG Fujian ZHOU Hang SU Yuan LI Fuwei YU Rencheng DONG Qing WANG Junjian LI Performance evaluation of microemulsion acid for integrated acid fracturing in Middle Eastern carbonate reservoirs Petroleum Exploration and Development Middle East carbonate microemulsion acid acid-rock reaction conductivity spent acid flowback permeability recovery |
| title | Performance evaluation of microemulsion acid for integrated acid fracturing in Middle Eastern carbonate reservoirs |
| title_full | Performance evaluation of microemulsion acid for integrated acid fracturing in Middle Eastern carbonate reservoirs |
| title_fullStr | Performance evaluation of microemulsion acid for integrated acid fracturing in Middle Eastern carbonate reservoirs |
| title_full_unstemmed | Performance evaluation of microemulsion acid for integrated acid fracturing in Middle Eastern carbonate reservoirs |
| title_short | Performance evaluation of microemulsion acid for integrated acid fracturing in Middle Eastern carbonate reservoirs |
| title_sort | performance evaluation of microemulsion acid for integrated acid fracturing in middle eastern carbonate reservoirs |
| topic | Middle East carbonate microemulsion acid acid-rock reaction conductivity spent acid flowback permeability recovery |
| url | http://www.sciencedirect.com/science/article/pii/S1876380423604586 |
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