Wide-angle reflection acquisition technology for ultradeep reservoirs based on large-scale low-frequency vibroseis
SU Hai1,2(), QIAO Jin1,2, ZHANG Zhong-Nan3, DU Zhong-Dong4, ZHANG Yong-Hao1,2, ZHAO Hui5, LI Ai-Rong1,2
1. School of Earth Science and Engineering, Xi'an Shiyou University, Xi'an 710065, China 2. Key Laboratory of Hydrocarbon Accumulation of Shaanxi Province, Xi'an 710065, China 3. The Seventh District of the Second Gas Production Plant in Yuyang District, Yulin City, Shaanxi Province,Yulin 719054,Cina 4. Changqing Geophysical Department,BGP Inc,CNPC, Xi'an 710016, China 5. The Third Treatment Plant of the Third Gas Production Plant of Changqing Oilfield, Xi'an 710018,China
With the intensification of hydrocarbon exploration in ultradeep reservoirs, conventional seismic exploration methods are no longer applicable to areas with complex surface structures and underground geological structures because they are difficult to acquire effective reflection information with high signal-to-noise ratio, the imaging effects of seismic data are poor, seismic profiles fail to clearly present the geological structures of study areas. Based on the large-scale low-frequency vibroseis excitation technology, the field acquisition requirements, and geological tasks, this study adopted a high-density two-dimensional wide-angle reflection seismic observation system to collect seismic data. This study selected the optimal field acquisition parameters suitable for the study area through numerical simulation of wide-angle seismic waves and field tests. As indicated by the results of this study, the wide-angle reflection acquisition technology for ultradeep reservoirs based on large-scale low-frequency vibroseis can acquire weakly reflected seismic signals at locations with far offset and strong energy, especially the deep low-frequency information, thus effectively improving the signal-to-noise ratio of seismic data. Compared with conventional seismic stacked sections, the wide-angle reflection seismic stacked sections have significantly improved quality, continuous events, clearly visible structural parts, and encouraging seismic imaging effects. The field production practices dominate that the wide-angle reflection seismic exploration technology can be applied to ultradeep hydrocarbon exploration.
Hu W R, Bao J W, Hu B. Trend and progress in global oil and gas exploration[J]. Petroleum Exploration and Development, 2013, 40(4):409-413.
doi: 10.1016/S1876-3804(13)60052-X
[2]
Goloshubin, Gennady M, Korneev. Seismic low-frequency effects from oil-saturated reservoir zones[C]// Salt Lake City: SEG International Exposition and Annual Meeting, 2002.
[3]
Castagna J P, Sun S, Siegfried R W. Instantaneous spectral analysis:Detection of low-frequency shadows associated with hydrocarbons[J]. The Leading Edge, 2003, 22(2):120-127.
doi: 10.1190/1.1559038
[4]
谭晔, 罗丹. 陶知非潜心打造勘探利器[J]. 中国石油石化, 2020(18):72-74.
[4]
Tan H, Luo D. Tao Z F to creat exploration weapon[J]. China Petrochem, 2020(18):72-74.
Zhou J Z, Zhang J H, Niu Q B, et al. Research on the application of key technologies for low-frequency vibroseis "two widths and one height" seismic data processing in Jiandingshan area of Qaidam Basin[J]. Geophysical and Geochemical Exploration, 2020, 44(2):313-320.
Yang J H, Zhang H Z. Outlook on the exploration and development technologies of unconventional,deep and offshore oil and gas[J]. World Petroleum Industry, 2020, 27(6):20-26.
[7]
Richards T C. Wide angle reflections and their application to fingding limestone structures in the footills of wetern Canada[J]. Geophysics, 1960, 25(2):385-407.
doi: 10.1190/1.1438709
Yang Z C, Zhang M, Jing L J, et al. Application of wide-angle seismic reflection to exploration of ultra deep reservoirs in Sichuan Basin[J]. Natural Gas Exploration and Development, 2020, 43(4):62-68.
Zhang Y, Duan M C, Zhong H, et al. Example and analysis of ultra-deep wide-angle seismic exploration technology in Tarim Basin[C]// Proceedings of 2019 Symposium on Geophysical Exploration Technology,China Petroleum Society,Editorial Department of Petroleum Geophysical Exploration, 2019:1310-1313.
Zhang J H, Zhang Z J, Zhang B B, et al. Low frequency signal influences on key seismic data processing procedures[J]. Oil Geophysical Prospecting, 2016, 51(1):54-62,19.
Yang W, Zhou G, Li H Y, et al. Seismic imaging technology for deep strike slip faults in carbonate reservoirs[J]. Xinjiang Petroleum Geology, 2021, 42(2):246-252.
Xie X L, Ma X M, Long H, et al. Parameter selection of seismic exploration in middle and shallow areas based on vibroseis[J]. Geophysical and Geochemical Exploration, 2021, 45(4):1004-1013.
Qiu Q L, Cao N W, Bai Y. Optimization of vibroseis excitation parameter and its application effect[J]. Geophysical and Geochemical Exploration, 2021, 45(3):686-691.
Zhou X Y, Yang Z C, Shi Y, et al. Research and application of ultra-deep wide-angle reflection seismic exploration technology in western Sichuan[C]// Proceedings of the 31st National Natural Gas Academic Annual Conference (2019), 2019:138-143.
Ni Y D, Du Z D, Wang Y D, et al. Wide-angle seismic acquisition and processing technology based on ultra-deep target layer[C]// Proceedings of the 2018 China Geosciences Joint Academic Annual Conference (forty-three)-Topic 93:Ultra-deep (oil and gas) Gravity Magnetic Electroseismic Exploration Technology,Topic 94:Deep Prediction Methods, 2018:61-63.
