Details
Original language | English |
---|---|
Pages (from-to) | 951-972 |
Number of pages | 22 |
Journal | Petroleum science |
Volume | 20 |
Issue number | 2 |
Early online date | 22 Jul 2022 |
Publication status | Published - Apr 2023 |
Abstract
Producing complex fracture networks in a safe way plays a critical role in the hot dry rock (HDR) geothermal energy exploitation. However, conventional hydraulic fracturing (HF) generally produces high breakdown pressure and results only in single main fracture morphology. Furthermore, HF has also other problems such as the increased risk of seismic events and consuption of large amount of water. In this work, a new stimulation method based on cyclic soft stimulation (CSS) and liquid nitrogen (LN2) fracturing, known as cyclic LN2 fracturing is explored, which we believe has the potential to solve the above issues related to HF. The fracturing performances including breakdown pressure and fracture morphology on granites under true-triaxial stresses are investigated and compared with cyclic water fracturing. Cryo-scanning electron microscopy (Cryo-SEM) tests and X-ray computed tomography (CT) scanning tests were used for quantitative characterization of fracture parameters and to evaluate the cyclic LN2 fracturing performances. The results demonstrate that the cyclic LN2 fracturing results in reduced breakdown pressure, with between 21% and 67% lower pressure compared with using cyclic water fracturing. Cyclic LN2 fracturing tends to produce more complex and branched fractures, whereas cyclic water fracturing usually produces a single main fracture under a low number of cycles and pressure levels. Thermally-induced fractures mostly occur around the interfaces of different particles. This study shows the potential benefits of cyclic LN2 fracturing on HDR. It is expected to provide theoretical guidance for the cyclic LN2 fracturing application in HDR reservoirs.
Keywords
- Cyclic injection, Fatigue damage, Hot dry rock, Liquid nitrogen fracturing, Thermal stress
ASJC Scopus subject areas
- Energy(all)
- Fuel Technology
- Earth and Planetary Sciences(all)
- Geotechnical Engineering and Engineering Geology
- Energy(all)
- Energy Engineering and Power Technology
- Earth and Planetary Sciences(all)
- Geophysics
- Earth and Planetary Sciences(all)
- Geology
- Earth and Planetary Sciences(all)
- Geochemistry and Petrology
- Earth and Planetary Sciences(all)
- Economic Geology
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In: Petroleum science, Vol. 20, No. 2, 04.2023, p. 951-972.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Enhance liquid nitrogen fracturing performance on hot dry rock by cyclic injection
AU - Hong, Chun Yang
AU - Yang, Rui Yue
AU - Huang, Zhong Wei
AU - Zhuang, Xiao Ying
AU - Wen, Hai Tao
AU - Hu, Xiao Li
N1 - Funding Information: This research was supported by the Youth Program of the National Natural Science Foundation of China (52004299), Major Project of the National Natural Science Foundation of China (52192621), the National Science Foundation for National R&D Program for Major Research Instruments of China (51827804), Beijing Outstanding Young Scientist Program (BJJWZYJH01201911414038) and the National Science Foundation for Distinguished Young Scholars of China (51725404). The authors also would like to thank Peking University for our Cryo-SEM work and the Yinghua Inspection and Testing (Shanghai) Co. Ltd for their help in CT scanning and data collection.
PY - 2023/4
Y1 - 2023/4
N2 - Producing complex fracture networks in a safe way plays a critical role in the hot dry rock (HDR) geothermal energy exploitation. However, conventional hydraulic fracturing (HF) generally produces high breakdown pressure and results only in single main fracture morphology. Furthermore, HF has also other problems such as the increased risk of seismic events and consuption of large amount of water. In this work, a new stimulation method based on cyclic soft stimulation (CSS) and liquid nitrogen (LN2) fracturing, known as cyclic LN2 fracturing is explored, which we believe has the potential to solve the above issues related to HF. The fracturing performances including breakdown pressure and fracture morphology on granites under true-triaxial stresses are investigated and compared with cyclic water fracturing. Cryo-scanning electron microscopy (Cryo-SEM) tests and X-ray computed tomography (CT) scanning tests were used for quantitative characterization of fracture parameters and to evaluate the cyclic LN2 fracturing performances. The results demonstrate that the cyclic LN2 fracturing results in reduced breakdown pressure, with between 21% and 67% lower pressure compared with using cyclic water fracturing. Cyclic LN2 fracturing tends to produce more complex and branched fractures, whereas cyclic water fracturing usually produces a single main fracture under a low number of cycles and pressure levels. Thermally-induced fractures mostly occur around the interfaces of different particles. This study shows the potential benefits of cyclic LN2 fracturing on HDR. It is expected to provide theoretical guidance for the cyclic LN2 fracturing application in HDR reservoirs.
AB - Producing complex fracture networks in a safe way plays a critical role in the hot dry rock (HDR) geothermal energy exploitation. However, conventional hydraulic fracturing (HF) generally produces high breakdown pressure and results only in single main fracture morphology. Furthermore, HF has also other problems such as the increased risk of seismic events and consuption of large amount of water. In this work, a new stimulation method based on cyclic soft stimulation (CSS) and liquid nitrogen (LN2) fracturing, known as cyclic LN2 fracturing is explored, which we believe has the potential to solve the above issues related to HF. The fracturing performances including breakdown pressure and fracture morphology on granites under true-triaxial stresses are investigated and compared with cyclic water fracturing. Cryo-scanning electron microscopy (Cryo-SEM) tests and X-ray computed tomography (CT) scanning tests were used for quantitative characterization of fracture parameters and to evaluate the cyclic LN2 fracturing performances. The results demonstrate that the cyclic LN2 fracturing results in reduced breakdown pressure, with between 21% and 67% lower pressure compared with using cyclic water fracturing. Cyclic LN2 fracturing tends to produce more complex and branched fractures, whereas cyclic water fracturing usually produces a single main fracture under a low number of cycles and pressure levels. Thermally-induced fractures mostly occur around the interfaces of different particles. This study shows the potential benefits of cyclic LN2 fracturing on HDR. It is expected to provide theoretical guidance for the cyclic LN2 fracturing application in HDR reservoirs.
KW - Cyclic injection
KW - Fatigue damage
KW - Hot dry rock
KW - Liquid nitrogen fracturing
KW - Thermal stress
UR - http://www.scopus.com/inward/record.url?scp=85138308186&partnerID=8YFLogxK
U2 - 10.1016/j.petsci.2022.07.004
DO - 10.1016/j.petsci.2022.07.004
M3 - Article
AN - SCOPUS:85138308186
VL - 20
SP - 951
EP - 972
JO - Petroleum science
JF - Petroleum science
SN - 1672-5107
IS - 2
ER -