Noise Characteristics and Denoising Methods of Long-Offset Transient Electromagnetic Method
The advantages of the long-offset transient electromagnetic method include deep detection and sensitive response to resistivity anomalies. It is widely used in underground mineral resources exploration, fluid identification in petroleum reservoirs, hydraulic fracturing, and dynamic residual oil and...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-08-01
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| Series: | Minerals |
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| Online Access: | https://www.mdpi.com/2075-163X/13/8/1084 |
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| author | Yang Xu Xingbing Xie Lei Zhou Biao Xi Liangjun Yan |
| author_facet | Yang Xu Xingbing Xie Lei Zhou Biao Xi Liangjun Yan |
| author_sort | Yang Xu |
| collection | DOAJ |
| description | The advantages of the long-offset transient electromagnetic method include deep detection and sensitive response to resistivity anomalies. It is widely used in underground mineral resources exploration, fluid identification in petroleum reservoirs, hydraulic fracturing, and dynamic residual oil and gas monitoring. After the primary field signal is turned off, grounded electrodes or coils are used to observe the secondary eddy field. The secondary field signal decays quickly and has a large dynamic range and a wide frequency band but is easily affected by various natural and human electromagnetic interferences. Therefore, noise reduction and distortion correction are important issues in the processing of transient electromagnetic data. This paper proposes a systematic noise interference suppression process. Multi-period and positive–negative bipolar signal stackings were used to remove random noise and suppress DC offset signals. Then, a time-domain inverse digital recursive method was applied to remove characteristic frequency signals, e.g., power frequency signals and their harmonic interference. A standard noise-free signal was constructed through forward modeling simulation and verified by adding different types of noise. Finally, high-quality transient electromagnetic secondary field attenuation signals were obtained through overlapping windowing technology. We applied this algorithm to obtain electromagnetic data from dynamic monitoring of hydraulic fracturing in Fuling shale gas and from a copper–iron metal mine in Daye City, demonstrating its effectiveness. |
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| id | doaj.art-baeb12e54eef4ccdb0a80ce22979b611 |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-10T23:42:59Z |
| publishDate | 2023-08-01 |
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| spelling | doaj.art-baeb12e54eef4ccdb0a80ce22979b6112023-11-19T02:21:32ZengMDPI AGMinerals2075-163X2023-08-01138108410.3390/min13081084Noise Characteristics and Denoising Methods of Long-Offset Transient Electromagnetic MethodYang Xu0Xingbing Xie1Lei Zhou2Biao Xi3Liangjun Yan4Key Laboratory of Exploration Technology for Oil and Gas Resources (Yangtze University), Ministry of Education, Wuhan 430100, ChinaKey Laboratory of Exploration Technology for Oil and Gas Resources (Yangtze University), Ministry of Education, Wuhan 430100, ChinaKey Laboratory of Exploration Technology for Oil and Gas Resources (Yangtze University), Ministry of Education, Wuhan 430100, ChinaKey Laboratory of Exploration Technology for Oil and Gas Resources (Yangtze University), Ministry of Education, Wuhan 430100, ChinaKey Laboratory of Exploration Technology for Oil and Gas Resources (Yangtze University), Ministry of Education, Wuhan 430100, ChinaThe advantages of the long-offset transient electromagnetic method include deep detection and sensitive response to resistivity anomalies. It is widely used in underground mineral resources exploration, fluid identification in petroleum reservoirs, hydraulic fracturing, and dynamic residual oil and gas monitoring. After the primary field signal is turned off, grounded electrodes or coils are used to observe the secondary eddy field. The secondary field signal decays quickly and has a large dynamic range and a wide frequency band but is easily affected by various natural and human electromagnetic interferences. Therefore, noise reduction and distortion correction are important issues in the processing of transient electromagnetic data. This paper proposes a systematic noise interference suppression process. Multi-period and positive–negative bipolar signal stackings were used to remove random noise and suppress DC offset signals. Then, a time-domain inverse digital recursive method was applied to remove characteristic frequency signals, e.g., power frequency signals and their harmonic interference. A standard noise-free signal was constructed through forward modeling simulation and verified by adding different types of noise. Finally, high-quality transient electromagnetic secondary field attenuation signals were obtained through overlapping windowing technology. We applied this algorithm to obtain electromagnetic data from dynamic monitoring of hydraulic fracturing in Fuling shale gas and from a copper–iron metal mine in Daye City, demonstrating its effectiveness.https://www.mdpi.com/2075-163X/13/8/1084long-offset transient electromagnetic methodsignal stackinginverse filteringoverlapped windowing |
| spellingShingle | Yang Xu Xingbing Xie Lei Zhou Biao Xi Liangjun Yan Noise Characteristics and Denoising Methods of Long-Offset Transient Electromagnetic Method Minerals long-offset transient electromagnetic method signal stacking inverse filtering overlapped windowing |
| title | Noise Characteristics and Denoising Methods of Long-Offset Transient Electromagnetic Method |
| title_full | Noise Characteristics and Denoising Methods of Long-Offset Transient Electromagnetic Method |
| title_fullStr | Noise Characteristics and Denoising Methods of Long-Offset Transient Electromagnetic Method |
| title_full_unstemmed | Noise Characteristics and Denoising Methods of Long-Offset Transient Electromagnetic Method |
| title_short | Noise Characteristics and Denoising Methods of Long-Offset Transient Electromagnetic Method |
| title_sort | noise characteristics and denoising methods of long offset transient electromagnetic method |
| topic | long-offset transient electromagnetic method signal stacking inverse filtering overlapped windowing |
| url | https://www.mdpi.com/2075-163X/13/8/1084 |
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