Two Improved Acquisition Systems for Deep Subsurface Exploration
Present land seismic surveys mainly focus on acquiring reflection data. The maximum offset is usually 1–1.5 times the depth of targets. Limited offset results in that the acquired diving waves only penetrate the shallow parts of the Earth model, far from targets. Thus, the reflection data are used t...
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| Format: | Article |
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Frontiers Media S.A.
2022-04-01
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| Series: | Frontiers in Earth Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2022.850766/full |
| _version_ | 1819023300082270208 |
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| author | Nengchao Liu Nengchao Liu Gang Yao Gang Yao Zhihui Zou Zhihui Zou Shangxu Wang Shangxu Wang Di Wu Di Wu Xiang Li Xiang Li Jianye Zhou Jianye Zhou |
| author_facet | Nengchao Liu Nengchao Liu Gang Yao Gang Yao Zhihui Zou Zhihui Zou Shangxu Wang Shangxu Wang Di Wu Di Wu Xiang Li Xiang Li Jianye Zhou Jianye Zhou |
| author_sort | Nengchao Liu |
| collection | DOAJ |
| description | Present land seismic surveys mainly focus on acquiring reflection data. The maximum offset is usually 1–1.5 times the depth of targets. Limited offset results in that the acquired diving waves only penetrate the shallow parts of the Earth model, far from targets. Thus, the reflection data are used to build the deep part of the velocity model with migration velocity analysis. However, two issues challenge the success of velocity model building. First, incomplete information. Limited offsets lead to a narrow aperture of observation, which results in an under-determined inversion system. One manifestation is the trade-off between the depth of interfaces/reflectors and the average velocity above them. Second, low signal-to-noise (S/N) ratios. Complex near-surface conditions and geologic structures lead to low S/N ratios for reflection data, which fails to build velocity with reflection data. The fundamental solution to these two issues is to acquire better data with an improved acquisition system. In this work, we propose two types of modified geometries to enhance the penetration depth of the diving waves, especially the first arrivals, which can be used to build a deeper velocity model effectively. Type-I geometry adds extra sparse sources on the extension line of the normal acquisition geometry, whereas Type-II geometry deploys extra sparse receivers on the extension line. Consequently, the new acquisition system includes ultra-large offsets, which acquire diving waves from the deep subsurface. These diving waves, including waveform and first-break time, are particularly useful for recovering deeper velocity, which has paramount significance for the exploration of deep and ultra-deep hydrocarbon reservoirs. Synthetic and field data examples preliminarily demonstrate the feasibility of this improved acquisition system. |
| first_indexed | 2024-12-21T04:36:42Z |
| format | Article |
| id | doaj.art-ec262f95f9744cf9815f3e728197a880 |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-12-21T04:36:42Z |
| publishDate | 2022-04-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-ec262f95f9744cf9815f3e728197a8802022-12-21T19:15:50ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632022-04-011010.3389/feart.2022.850766850766Two Improved Acquisition Systems for Deep Subsurface ExplorationNengchao Liu0Nengchao Liu1Gang Yao2Gang Yao3Zhihui Zou4Zhihui Zou5Shangxu Wang6Shangxu Wang7Di Wu8Di Wu9Xiang Li10Xiang Li11Jianye Zhou12Jianye Zhou13State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing, ChinaCollege of Geophysics, China University of Petroleum (Beijing), Beijing, ChinaState Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing, ChinaUnconventional Petroleum Research Institute, China University of Petroleum (Beijing), Beijing, ChinaKey Lab of Submarine Geosciences and Prospecting Techniques MOE, Ocean University of China, Qingdao, ChinaCollege of Marine Geosciences, Ocean University of China, Qingdao, ChinaState Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing, ChinaCollege of Geophysics, China University of Petroleum (Beijing), Beijing, ChinaState Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing, ChinaCollege of Geophysics, China University of Petroleum (Beijing), Beijing, ChinaState Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing, ChinaUnconventional Petroleum Research Institute, China University of Petroleum (Beijing), Beijing, ChinaState Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing, ChinaCollege of Geophysics, China University of Petroleum (Beijing), Beijing, ChinaPresent land seismic surveys mainly focus on acquiring reflection data. The maximum offset is usually 1–1.5 times the depth of targets. Limited offset results in that the acquired diving waves only penetrate the shallow parts of the Earth model, far from targets. Thus, the reflection data are used to build the deep part of the velocity model with migration velocity analysis. However, two issues challenge the success of velocity model building. First, incomplete information. Limited offsets lead to a narrow aperture of observation, which results in an under-determined inversion system. One manifestation is the trade-off between the depth of interfaces/reflectors and the average velocity above them. Second, low signal-to-noise (S/N) ratios. Complex near-surface conditions and geologic structures lead to low S/N ratios for reflection data, which fails to build velocity with reflection data. The fundamental solution to these two issues is to acquire better data with an improved acquisition system. In this work, we propose two types of modified geometries to enhance the penetration depth of the diving waves, especially the first arrivals, which can be used to build a deeper velocity model effectively. Type-I geometry adds extra sparse sources on the extension line of the normal acquisition geometry, whereas Type-II geometry deploys extra sparse receivers on the extension line. Consequently, the new acquisition system includes ultra-large offsets, which acquire diving waves from the deep subsurface. These diving waves, including waveform and first-break time, are particularly useful for recovering deeper velocity, which has paramount significance for the exploration of deep and ultra-deep hydrocarbon reservoirs. Synthetic and field data examples preliminarily demonstrate the feasibility of this improved acquisition system.https://www.frontiersin.org/articles/10.3389/feart.2022.850766/fullseismic acquisition geometrydiving wavevelocity model buildingnodal seismometerseismic vibrator |
| spellingShingle | Nengchao Liu Nengchao Liu Gang Yao Gang Yao Zhihui Zou Zhihui Zou Shangxu Wang Shangxu Wang Di Wu Di Wu Xiang Li Xiang Li Jianye Zhou Jianye Zhou Two Improved Acquisition Systems for Deep Subsurface Exploration Frontiers in Earth Science seismic acquisition geometry diving wave velocity model building nodal seismometer seismic vibrator |
| title | Two Improved Acquisition Systems for Deep Subsurface Exploration |
| title_full | Two Improved Acquisition Systems for Deep Subsurface Exploration |
| title_fullStr | Two Improved Acquisition Systems for Deep Subsurface Exploration |
| title_full_unstemmed | Two Improved Acquisition Systems for Deep Subsurface Exploration |
| title_short | Two Improved Acquisition Systems for Deep Subsurface Exploration |
| title_sort | two improved acquisition systems for deep subsurface exploration |
| topic | seismic acquisition geometry diving wave velocity model building nodal seismometer seismic vibrator |
| url | https://www.frontiersin.org/articles/10.3389/feart.2022.850766/full |
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